TWI790949B - Semiconductor device - Google Patents

Abstract

Disclosed are a semiconductor device and a method of manufacturing the same. The semiconductor device includes a semiconductor structure including a first conductive semiconductor layer, a second conductive semiconductor layer, an active layer disposed between the first conductive semiconductor layer and the second conductive semiconductor layer, and a plurality of recesses disposed up to a portion of the first conductive semiconductor layer through the second conductive semiconductor layer and the active layer, first electrodes disposed inside the plurality of recesses and electrically connected to the first conductive semiconductor layer, a second electrode electrically connected to the second conductive semiconductor layer, a third electrode disposed on the second electrode; and a reflective layer disposed on the second electrode and the third electrode.

Description

Semiconductor device

The present invention relates to a semiconductor device and a manufacturing method thereof.

Semiconductor devices including compounds such as GaN and AlGaN have many advantages such as energy in an easily tunable wide frequency gap and the like, and can be variously used for light emitting devices, light receiving devices, various diodes, and the like.

Specifically, light-emitting elements (such as light-emitting diodes or laser diodes) using synthetic semiconductor materials such as group III-V elements or group II-VI elements can be achieved through the development of thin film growth technology and element materials. Various colors of light such as red light, green light, blue light, and ultraviolet light are realized, and white light with high efficiency is also realized by using fluorescent materials or by combining colors. Compared with conventional light sources such as fluorescent lamps, incandescent lamps and the like, light emitting devices have advantages such as low power consumption, semi-permanent life, fast response, safety and environmental friendliness.

In addition, light-receiving elements (such as photodetectors or solar cells) manufactured using synthetic semiconductor materials such as group III-V elements or group II-VI elements can absorb Photocurrents are generated to utilize light in various wavelength ranges from gamma rays to radiation wavelengths. In addition, the light-receiving element has advantages such as fast response speed, safety, environmental friendliness, and simple control of element materials, and thus can be easily used in power control, microwave circuits, or communication modules.

Therefore, semiconductor devices are increasingly used in transmission modules of optical communication components, light-emitting diode backlights that replace cold cathode fluorescent lamps (CCFL) to form backlights for liquid crystal display (LCD) devices, and can replace fluorescent lamps or White light-emitting diode lighting devices for incandescent bulbs, automotive headlights, traffic lights, and sensors for detecting gas and fire. In addition, the semiconductor device can be applied to high-frequency application circuits, other power control devices and communication modules.

In particular, light-emitting elements emitting light in the ultraviolet wavelength range can be used for solidification of liquids, medical use and sterilization by performing a curing or sterilization action.

Recently, research on ultraviolet light-emitting elements has been actively conducted. However, there are problems that UV-emitting elements are still difficult to implement in a vertical form and have relatively low light extraction efficiency.

In addition, there is a problem that current does not diffuse sufficiently in the semiconductor layer because the ultraviolet light-emitting element has a high aluminum (Al) content. As a result, the light output of the UV-emitting element becomes weaker, and the operating voltage increases.

The present invention relates to providing a vertical ultraviolet light-emitting component.

The present invention is concerned with providing a method of fabricating a UV-emitting device that facilitates a laser lift-off (LLO) process.

The present invention relates to providing a semiconductor device with improved light extraction rate.

The present invention is concerned with providing a semiconductor device with excellent current spreading efficiency.

The present invention relates to providing a semiconductor device with reduced operating voltage.

It should be noted that the objects of the present invention are not limited to those described above. And other objects of the present invention will be apparent to those skilled in the art from the following description.

According to one aspect of the present invention, a semiconductor device is provided, which includes a semiconductor structure, and the semiconductor structure includes a first conductivity type semiconductor layer, a second conductivity type semiconductor layer, The active layer between the semiconductor layers of the first conductivity type and a plurality of notches that reach a part of the first conductivity type semiconductor layer and pass through the second conductivity type semiconductor layer and the active layer; are arranged inside the plurality of notches and A plurality of first electrodes electrically connected to the first conductivity type semiconductor layer; a second electrode electrically connected to the second conductivity type semiconductor layer; and a light absorbing layer disposed along the edge of the semiconductor structure, wherein the The light absorbing layer is thicker than the second electrode.

The light absorbing layer and the second electrode may include indium tin oxide (ITO).

The width of the light absorbing layer may be smaller than the shortest distance from the outermost side of the semiconductor structure to the second electrode.

The semiconductor device may further include a first conductive layer electrically connected to the first electrode, a second conductive layer electrically connected to the second electrode, and a conductive substrate electrically connected to the first conductive layer.

The semiconductor device may further include a first insulating layer disposed inside the recess and configured to insulate the first conductive layer from the active layer and the second conductive type semiconductor layer, and disposed between the first conductive layer and the second conductive layer the second insulating layer.

The light absorbing layer may be disposed between the second conductive type semiconductor layer and the first insulating layer.

The active layer can emit light in the ultraviolet wavelength range.

According to another aspect of the present invention, there is provided a method of manufacturing a semiconductor device, which includes forming a semiconductor device by sequentially forming a main absorption layer, a first conductivity type semiconductor layer, an active layer, and a second conductivity type semiconductor layer on a substrate. structure, forming a light absorbing layer on a channel layer disposed between a plurality of chip regions of the semiconductor structure, forming electrodes on the plurality of chip regions and the channel layer, and separating the substrate by applying laser light to the substrate The substrate, wherein the main absorption layer and the light absorption layer absorb the laser light.

The method may further include separating the plurality of wafer regions by dicing the channel layer after separating the substrate, wherein the separated wafer regions include a portion of the light absorbing layer.

The method may further include separating the plurality of wafer regions by dicing the channel layer after separating the substrate, wherein the separated wafer regions include a portion of the light absorbing layer.

Forming the light absorbing layer may include forming a recess and a protruding portion protruding from a bottom surface of the recess by etching the channel layer, and the protruding portion may surround a plurality of wafer regions.

The present invention further provides a semiconductor device, the semiconductor device includes: a semiconductor structure, which includes a first conductivity type semiconductor layer, a second conductivity type semiconductor layer, disposed between the first conductivity type semiconductor layer and the second conductivity type semiconductor layer An active layer between the semiconductor layers and a plurality of notches that reach a part of the first conductive type semiconductor layer and pass through the second conductive type semiconductor layer and the active layer; a plurality of first electrodes, which are arranged on in the recesses and electrically connected to the first conductive type semiconductor layer; a second electrode electrically connected to the second conductive type semiconductor layer; a third electrode disposed on the second electrode; and A reflection layer is arranged on the second electrode and the third electrode.

The present invention further provides a semiconductor device, the semiconductor device includes: a semiconductor Bulk structure, which includes a first conductivity type semiconductor layer, a second conductivity type semiconductor layer, an active layer arranged between the first conductivity type semiconductor layer and the second conductivity type semiconductor layer and set up to the first conductivity type semiconductor layer A plurality of notches that are part of a conductive semiconductor layer and pass through the second conductive semiconductor layer and the active layer; a plurality of first electrodes are arranged in the notches and are electrically connected to the first conductive type semiconductor layer; and a second electrode, which is electrically connected to the second conductivity type semiconductor layer; an electron blocking layer, disposed between the active layer and the second conductivity type semiconductor layer, wherein the active layer includes a plurality of wells layer and multiple barrier layers; the second conductivity type semiconductor layer includes a 2-1 conductivity type semiconductor layer and a 2-2 conductivity type semiconductor layer; the 2-1 conductivity type semiconductor layer is in contact with the second electrode, and the 2 -2 conductivity type semiconductor layer is disposed between the electron blocking layer and the 2-1 conductivity type semiconductor layer; and the aluminum content of the 2-1 conductivity type semiconductor layer is smaller than the aluminum content of the well layer, and the 2-2 conductivity type semiconductor layer The aluminum content of the type semiconductor layer is higher than that of the well layer.

1: Substrate/semiconductor device

2: Ontology

2a: Layering

2b: layered

2c: layering

2d: layered

2e: layered

3: Groove

4: light transmission layer

5a: The first lead frame

5b: The second lead frame

5c: The third lead frame

5d: The fourth lead frame

5e: fifth lead frame

10: Wafer area

10a: Semiconductor device

10b: Semiconductor device

10c: Semiconductor device

10d: Semiconductor device

11a: notch

11b: protrusion

12: Channel layer

13: Light absorbing layer

13a: side surface

13b: side surface

13c: side surface

13d: side surface

21: First opening

22: Second opening

120:Semiconductor Structures

124: first conductivity type semiconductor layer

124a: 1-1 conductivity type semiconductor layer

124b: 1-2 conductivity type semiconductor layer

126: active layer

126a: well layer

126b: barrier layer

127: second conductivity type semiconductor layer

127a: 2-1 conductivity type semiconductor layer

127b: 2-2 Conduction Type Semiconductor Layer

127c: section

127G: first surface

128: notch

129: Electron blocking layer

129a: Section 1-1

129b: Section 1-2

129c: notch

131: the first insulating layer

131a: Extension

132: Second insulating layer

142: first electrode

143: upper surface

146: second electrode

150: second conductive layer

160: bonding layer

165: the first conductive layer

166: Second electrode pad

170: Substrate

180: passivation layer

246: second electrode

247: The third electrode

247-1: unit electrode

247-2: side electrode

247a: The first layer

247b: second layer

247c: The third layer

248: reflective layer

248a: First Hole/Extension

L ₁ : Width

L ₂ : the shortest distance

L ₁₁ : first width

L ₁₂ : Extension

d ₁ : thickness

d ₂ : Thickness

d ₃ : thickness

d ₄ : distance

M: electrode layer

P1: Main absorbent layer

P ₂ : Effective light-emitting area

P ₃ : Low current density area

S ₁ : electric hole

W ₁ : diameter

W ₂ : Interval

W ₃ : Interval

W ₄ : Width

θ ₁ : Inclination angle

θ ₅ : Inclination angle

For those generally skilled in the art, the above and other objects, features and advantages of the present invention will become more apparent by describing in detail exemplary embodiments with reference to the accompanying drawings, in which:

FIG. 1 is a conceptual view of a semiconductor device according to a first embodiment of the present invention;

Figure 2a is an enlarged view of part A of Figure 1;

2b is a plan view of the semiconductor device according to the first embodiment of the present invention;

FIG. 3 is a diagram illustrating problems that occur when a substrate is removed from a conventional structure;

4a to 4c are views showing a damaged state of a semiconductor device when the substrate is removed;

5a to 5d are a view for describing a method of manufacturing the semiconductor device according to the first embodiment of the present invention;

6 is a view showing a state in which a semiconductor structure is formed by mesa etching to form a channel layer and a light absorbing layer between a plurality of semiconductor devices;

7 is a view showing a state in which the substrate is removed from the semiconductor structure;

Fig. 8 is a view showing a modified example of Fig. 6;

FIG. 9 is a view showing a state in which the substrate is removed from the semiconductor structure having the structure in FIG. 8 picture;

10 is a conceptual view of a semiconductor device according to a second embodiment of the present invention;

Figures 11a to 11b are diagrams for depicting the structure of improving the light output according to the change of the number of notches;

12 is a plan view of the semiconductor device according to the second embodiment of the present invention;

Fig. 13 is a sectional view viewed along the A-A line of Fig. 12;

Fig. 14 is a sectional view of a third electrode of the present invention;

Fig. 15 a is the view showing the state of the third electrode absorbing ultraviolet light;

Fig. 15b is a graph showing the reflectivity measured by different reflective layers relative to light in a 280nm wavelength band;

Fig. 16 is a view showing a state in which a plurality of unit electrodes surround a notch;

Fig. 17 is an enlarged view of part A of Fig. 12;

Fig. 18 is a view showing a modified example of Fig. 13;

Fig. 19 is a view showing an example of the modification of the third electrode of the present invention;

20 is a plan view of a semiconductor device according to a third embodiment of the present invention;

Fig. 21 is a sectional view viewed along the B-B line of Fig. 20;

22 is a cross-sectional view of a semiconductor device according to a fourth embodiment of the present invention;

Fig. 23 is an enlarged view of part B of Fig. 22;

24 is a conceptual view of a semiconductor device according to a fifth embodiment of the present invention;

Figure 25a is an enlarged view of part A of Figure 24;

Figure 25b is a partially enlarged view of one of Figure 25a;

26 is a graph showing an aluminum content in a thickness direction of the semiconductor device according to the fifth embodiment of the present invention;

Figures 27a and 27b are diagrams for depicting structures that improve light output according to changes in the number of notches;

28 is a plan view of the semiconductor device according to the fifth embodiment of the present invention;

29 is a plan view of a semiconductor device according to a sixth embodiment of the present invention;

30 is a plan view of a semiconductor device according to a seventh embodiment of the present invention;

31 is a plan view of a semiconductor device according to an eighth embodiment of the present invention;

32 is a graph showing light output and power conversion efficiency (wall-plug efficiency, WPE) measured by the semiconductor devices according to the fifth to eighth embodiments;

33 is a conceptual view of a semiconductor device according to a ninth embodiment of the present invention;

Figure 34 is a plan view of Figure 33;

35 is a conceptual view of a semiconductor device package according to an embodiment of the present invention;

36 is a plan view of a semiconductor device package according to an embodiment of the present invention; and

Fig. 37 is a view showing a modified example of Fig. 36 .

The embodiments of the present invention may be modified in other forms, or several embodiments may be combined with each other. The scope of the present invention is not limited to each of the embodiments described below.

Even when the content described in a specific embodiment is not described in other embodiments, the content can be understood as being related to the other embodiments unless otherwise described or the content contradicts the specific embodiment in other embodiments.

For example, when the features of element A are described in one particular embodiment and the features of element B are described in another embodiment, it should be understood that embodiments in which element A and element B are combined are within the scope of the invention and spirit, even when such embodiments are not explicitly described.

As used herein, it will be understood that when an element is referred to as being formed "on or under" another element, it can be in direct contact with the other element, or at least one intervening element may also be present. Furthermore, the terms "upper (above)" or "lower (below)" can encompass both an orientation of above and below.

Hereinafter, embodiments of the present invention will be described more fully with reference to the accompanying drawings so that those skilled in the art can easily implement the embodiments.

Fig. 1 is a conceptual view of a semiconductor device according to a first embodiment of the present invention, Fig. 2A is an enlarged view of part A of Fig. 1 , and Fig. 2B is the view according to the first embodiment of the present invention A plan view of a semiconductor device.

Referring to Fig. 1, the semiconductor device according to this first embodiment of the present invention includes: a semiconductor structure 120, which includes a first conductivity type semiconductor layer 124, an active layer 126 and a second conductivity type semiconductor layer 127; a first electrode 142, which is connected to the first conductivity type semiconductor The bulk layer 124 is electrically connected; and a plurality of second electrodes 246 are electrically connected to the second conductive type semiconductor layer 127 .

The semiconductor structure 120 can output light in an ultraviolet (UV) wavelength range. For example, the semiconductor structure 120 can output light in a near ultraviolet wavelength range (UV-A), output a light in an extreme ultraviolet wavelength range (UV-B) and output light in a deep ultraviolet wavelength range (UV-C) . The wavelength range can be determined by a content ratio of aluminum (Al) in the semiconductor structure 120 .

For example, the light in the near ultraviolet wavelength range (UV-A) may have a wavelength in the range of 320nm to 420nm, and the light in the extreme ultraviolet wavelength range (UV-B) may have a wavelength in the range of 280nm to 320nm. wavelength, and the light in the deep ultraviolet wavelength range (UV-C) may have a wavelength in the range of 100 nm to 280 nm.

The semiconductor structure 120 includes the first conductive type semiconductor layer 124 , the second conductive type semiconductor layer 127 and the active layer 126 disposed between the first conductive type semiconductor layer 124 and the second conductive type semiconductor layer 127 .

x1

1,0

y1

1,and 0

x1+y1

1)的半導體材料，例如GaN、AlGaN、InGaN、InAlGaN及諸如此類。該第一摻雜劑可為一N型摻雜劑，例如Si、Ge、Sn、Se或Te。當該第一摻雜劑為一N型摻雜劑，用該第一摻雜劑來摻雜之該第一導電型半導體層124可為一N型半導體層。 The first conductivity type semiconductor layer 124 can be realized by a compound semiconductor, such as a group III-V element, a group II-VI element or the like, and can be doped with a first dopant. The first conductivity type semiconductor layer 124 can be selected from a composition chemical formula: In _x1 Al _y1 Ga _1-x1-y1 N(0

x1

1,0

y1

1, and 0

x1+y1

1) Semiconductor materials such as GaN, AlGaN, InGaN, InAlGaN and the like. The first dopant can be an N-type dopant, such as Si, Ge, Sn, Se or Te. When the first dopant is an N-type dopant, the first conductive type semiconductor layer 124 doped with the first dopant can be an N-type semiconductor layer.

The active layer 126 is disposed between the first conductive type semiconductor layer 124 and the second conductive type semiconductor layer 127 . The active layer 126 is a layer, and the electrons (or holes) injected through the first conductive type semiconductor layer 124 and the holes (or electrons) injected through the second conductive type semiconductor layer 127 are in this layer. meet. In the active layer 126, when the electron and the hole coincide, the electron can be converted to a low energy level and can generate light with an ultraviolet wavelength.

The active layer 126 can have any of the following structures: single well structure, multi-well structure, single quantum well (SQW) structure, multiple quantum well (MQW) structure, quantum dot structure and quantum wire structure, and the active layer The structure is not limited to this.

x5

1,0

y2

1,and 0

x5+y2

1)的一半導體材料或是選自AlInN、AlGaAs、GaP、GaAs、GaAsP及AlGaInP構成之一群組中的一材料來形成。當該第二摻雜劑為一P型摻雜劑，例如Mg、Zn、Ca、Sr、Ba或諸如此類，用該第二摻雜劑來摻雜之該第二導電型半導體層127可為一P型半導體層。 The second conductivity type semiconductor layer 127 can be realized by a compound semiconductor, such as a group III-V element, a group II-VI element or the like, and can be doped with a second dopant. The second conductivity type semiconductor layer 127 can be composed of a chemical formula: In _x5 Al _y2 Ga _1-x5-y2 N(0

x5

1,0

y2

1, and 0

x5+y2

1) is formed by a semiconductor material or a material selected from the group consisting of AlInN, AlGaAs, GaP, GaAs, GaAsP and AlGaInP. When the second dopant is a P-type dopant, such as Mg, Zn, Ca, Sr, Ba or the like, the second conductivity type semiconductor layer 127 doped with the second dopant can be a P-type semiconductor layer.

The semiconductor structure 120 according to this embodiment includes a plurality of notches. The notches can be disposed from a first surface 127G of the second conductive type semiconductor layer 127 to a part of the first conductive type semiconductor layer 124 through the active layer 126 .

The first electrode 142 can be disposed in the recess 128 and electrically connected to the first conductive type semiconductor layer 124 . A first conductive layer 165 can be disposed in the recesses 128 to electrically connect the first electrodes 142 . A first insulating layer 131 can be disposed in the recesses 128 to electrically isolate the first conductive layer 165 from the second conductive type semiconductor layer 127 and the active layer 126 .

As the aluminum content of the semiconductor structure 120 increases, a current spreading performance of the semiconductor structure 120 may decrease. In addition, when compared with a GaN-based blue light-emitting device (transverse magnetic field mode TM mode), the total amount of light emitted to one side surface of the active layer is increased. The transverse magnetic field mode can mainly occur in a UV semiconductor device.

The UV semiconductor device may have a lower current spreading performance than the GaN-based blue semiconductor device. Therefore, compared with the GaN-based blue semiconductor device, the ultraviolet light semiconductor device needs to be provided with relatively more first electrodes 142 .

The second electrodes 246 can be disposed on the first surface 127G of the second conductive type semiconductor layer 127 . The second electrode 246 may include a light-transmitting electrode that absorbs relatively less amount of ultraviolet light.

The first electrode 142 and the second electrode 246 can be ohmic electrodes. The first electrode 142 and the second electrode 246 may include at least one of the following: indium tin oxide (ITO), indium zinc oxide (IZO), indium zinc tin oxide (IZTO), indium zinc aluminum oxide (IAZO), oxide Indium gallium zinc oxide (IGZO), indium tin gallium oxide (IGTO), zinc aluminum oxide (AZO), antimony tin oxide (ATO), zinc gallium oxide (GZO), oxygen Indium zinc nitride (IZON), aluminum-gallium zinc oxide (AGZO), indium-gallium zinc oxide (IGZO), zinc oxide (ZnO), iridium oxide (IrOx), ruthenium oxide (RuOx), nickel oxide (NiO) , ruthenium oxide/indium tin oxide (RuOx/ITO), nickel/iridium oxide/gold (Ni/IrOx/Au), nickel/iridium oxide gold/indium tin oxide (Ni/IrOx/Au/ITO), Ag (silver) , nickel (Ni), chromium (Cr), titanium (Ti), aluminum (Al), rhodium (Rh), palladium (Pd), iridium (Ir), tin (Sn), indium (In), ruthenium (Ru) , magnesium (Mg), zinc (Zn), platinum (Pt), gold (Au), hafnium (Hf), and the like, but the present invention is not limited to the above materials.

A light absorbing layer 13 may be disposed on one of the outermost edges of the semiconductor device. The light absorbing layer 13 can absorb a laser light that is used to remove the substrate on which the semiconductor structure is grown. In some cases, the light absorbing layer 13 can absorb the light emitted from the active layer 126 . Therefore, an area of the light absorbing layer 13 is preferably reduced.

Referring to FIG. 2 a , the light absorbing layer 13 may be disposed between the second conductive type semiconductor layer 127 and the first insulating layer 131 . A width L ₁ of the light absorbing layer 13 in a horizontal direction (an X-axis direction) may be smaller than a shortest distance L ₂ from an outermost side of the semiconductor device to the second electrode 246 .

Since the light-absorbing layer 13 can absorb the ultraviolet light generated in the active layer 126 , when the width L ₁ of the light-absorbing layer 13 increases, the light extraction rate can decrease. Therefore, the width _L1 of the light absorbing layer 13 can be formed to be short so as not to overlap with the semiconductor structure 120 in a thickness direction (a Y-axis direction). That is to say, the light absorbing layer 13 may have a first width L ₁₁ . However, the present invention is not limited thereto, and the light absorbing layer 13 may further extend inward to L ₁₂ in the semiconductor device to overlap with the semiconductor structure 120 in the thickness direction. The extended portion L ₁₂ of the light absorbing layer 13 can be formed with manufacturing tolerance or process margin.

The width L ₁ of the light absorbing layer 13 may be 1 μm to 20 μm at the outermost side of the semiconductor device, but is not limited thereto.

It may be advantageous to form the second electrode 246 to be thin so as not to absorb light generated at the active layer 126 . For example, a thickness _d1 of the second electrode 246 may be 1 nm to 20 nm. Conversely, it may be advantageous to form the light absorbing layer 13 thick so as to absorb the maximum amount of laser light to remove the growth substrate. For example, a thickness d2 of the light absorbing layer 13 may be 15 nm to 100 nm.

Therefore, when the light absorbing layer 13 and the second electrode 246 have the same composition, the thickness d2 of the light absorbing layer 13 can be greater than the thickness d ₁ of the second electrode 246 . For example, the light absorbing layer 13 and the second electrode 246 can be a conductive oxidation electrode, which has a material such as indium tin oxide (ITO), but the invention is not limited thereto. The material of the light absorbing layer 13 is not limited as long as it has an energy band gap smaller than that of the laser light used for laser lift-off (LLO).

The light absorbing layer 13 and the second electrode 246 can be disposed on a lower surface of the semiconductor structure 120 . That is to say, the light absorbing layer 13 and the second electrode 246 can be coplanar. For example, the light absorbing layer 13 and the second electrode 246 can be disposed on the lower surface 127G of the second conductive type semiconductor layer 127 of the semiconductor structure 120 , but the invention is not limited thereto. Furthermore, the light absorbing layer 13 can be disposed between a passivation layer and the first insulating layer 131 , and an outer end thereof can be exposed outside.

Referring to FIG. 2b, the light absorbing layer 13 may be disposed on four side surfaces 13a, 13b, 13c and 13d of the semiconductor device along the edges of the semiconductor device. That is to say, the light absorbing layer 13 can be continuously disposed along the side surface of the semiconductor structure 120 . However, the present invention is not limited thereto, and the light absorbing layer 13 may only consist of a first light absorbing layer 13a disposed on a first side surface and a second light absorbing layer 13a disposed on a second side surface. The absorption layer 13b is composed. That is, the light absorbing layer 13 can be selectively provided only on a desired one of the side surfaces.

Referring to FIG. 1 again, a second conductive layer 150 can be electrically connected to the second electrodes 246 . The second conductive layer 150 may include a material with good adhesion to the first insulating layer 131 . For example, the second conductive layer 150 can be formed from at least one material selected from a group consisting of Cr, Al, Ti, Ni, Au, and the like or alloys thereof, and can be a single layer or multiple layers.

A second electrode pad 166 may be disposed at a corner of the semiconductor device. The second electrode pad 166 may have a concave central part and an upper surface may have a concave part and a convex part. A wire (not shown) can be connected to the concave portion of the upper surface of the second electrode pad 166 . Therefore, a connection area can be enlarged and the second electrode pad 166 and the wire can be connected more firmly.

Since the second electrode pad 166 can reflect light, when the second electrode pad 166 gets closer to the semiconductor structure 120 , the light extraction rate can be improved accordingly.

The second electrode pad 166 can be disposed at a higher level than the active layer 126 . Therefore, the second electrode pad 166 can reflect upwardly the light emitted from the active layer 126 in the horizontal direction of the device, and thus the light extraction rate can be improved accordingly, and a direction angle of the light can be controlled.

The second electrode pad 166 can pass through the first insulating layer 131 and can electrically connect the second conductive layer 150 and the second electrode 246 .

The first insulating layer 131 can electrically isolate the first electrode 142 from the active layer 126 and the second conductive type semiconductor layer 127 . Furthermore, the first insulating layer 131 can cover the light absorbing layer 13 .

The first insulating layer 131 can be formed by at least one selected from a group consisting of the following materials: SiO ₂ , Six _{O y} , Si ₃ N ₄ , _Six N _y , SiO _x N _y , Al ₂ O ₃ , TiO _2. AlN and the like, however, the present invention is not limited thereto. The first insulating layer 131 can be formed as a single layer or multiple layers. For example, the first insulating layer 131 can be a distributed Bragg reflector (DBR), which has a multilayer structure including silicon oxide (Si oxide) or a titanium compound (Ti compound). However, the present invention is not limited thereto, and the first insulating layer 131 may have various reflective structures.

A second insulating layer 132 can electrically isolate the second conductive layer 150 from the first conductive layer 165 . The first conductive layer 165 can pass through the second insulating layer 132 and can be electrically connected to the first electrode 142 .

The first conductive layer 165 and a bonding layer 160 can be arranged according to a shape of the lower surface of the semiconductor structure 120 and a shape of the recess 128 . The first conductive layer 165 can be made of a material with high reflectivity. For example, the first conductive layer 165 may include aluminum. When the first conductive layer 165 includes aluminum, the first conductive layer 165 reflects the light emitted from the active layer 126 upward, thereby improving the light extraction efficiency.

The bonding layer 160 may include a conductive material. For example, the bonding layer 160 may include a material selected from a group consisting of: gold (gold), tin (tin), indium (indium), aluminum (aluminum), silicon (silicon), silver (silver) , nickel (nickel) and copper (copper), or one of their alloys (alloy). The bonding layer 160 can bond the semiconductor structure 120 to a substrate 170 during a laser lift-off process.

The substrate 170 can be made of a conductive material. For example, the substrate 170 may include a metal or a semiconductor material. The substrate 170 can be a metal with excellent electrical and/or thermal conductivity. In this case, the heat generated during the operation of the semiconductor device can be quickly discharged outside.

The substrate 170 may include a material selected from a group consisting of: silicon, molybdenum, tungsten, copper and aluminum or an alloy thereof . The substrate 170 can electrically connect the first conductive type semiconductor layer 124 with an external electrode.

The passivation layer 180 can be formed on the upper surface and side surfaces of the semiconductor structure 120 . The passivation layer 180 can be partially in ohmic contact with the first insulating layer 131 at a region adjacent to the second electrode 246 or under one of the second electrodes 246 .

An uneven part may be formed on the upper surface of the semiconductor structure 120 . The uneven portions are used to improve the extraction efficiency of light emitted by the semiconductor structure 120 . The uneven parts may have different average heights according to the wavelength of the ultraviolet light. The UV-C may have a height of about 300nm to 800nm, so when the average height thereof is about 500nm to 600nm, the light extraction rate may be improved.

FIG. 3 is a view for describing a problem that occurs when a substrate is removed from a conventional structure, and FIGS. 4a to 4c show a state where a semiconductor device is damaged when the substrate is removed. view.

Referring to FIG. 3 , in the method for removing the substrate of a semiconductor device, a semiconductor structure 120 can be formed on a substrate 1 , and then the semiconductor structure 120 can be divided into a plurality of wafer regions 10 and a channel layer 12 . Then, a plurality of electrode layers M1 can be formed on the semiconductor structure 120, and the substrate 1 can be removed.

A laser light can be used to remove the substrate 1 . A main absorption layer P1 for absorbing a laser light can be formed in the semiconductor structure 120 . However, when the semiconductor structure 120 is an ultraviolet semiconductor structure, the energy of the laser light is so strong that the laser light can pass through the semiconductor structure 120 and damage the channel layer 12 .

For example, when the laser light passes through the main absorption layer P1 and is absorbed into the electrode layer M1 formed on the channel layer 12, separation may occur in the electrode layer M1. The electrode layer M1 can be a first conductive layer or a bonding layer, but the invention is not limited thereto. On the other hand, by Layers that can partially absorb the laser light (eg, electrodes) are disposed in the wafer regions 10 , and the wafer regions 10 can be relatively less damaged than the channel layer 12 .

However, the electrode layer M1 formed on the channel layer 12 is connected to the electrode layers M1 of the wafer regions 10 . Therefore, when separation occurs in the electrode layer M1 of the channel layer 12, the wafer regions 10 may also be damaged. Referring to Figures 4a to 4c, it can be seen that the channel layer 12 is damaged and thus the wafer regions 10 are also damaged.

Therefore, it is important to prevent the laser light from being transmitted to the channel layer 12 or damage to the channel layer 12 from amplifying to the wafer regions 10 .

5a to 5d are views for describing a method of manufacturing the semiconductor device according to the first embodiment of the present invention, and FIG. 6 is a view showing a semiconductor structure formed on a plurality of semiconductor devices by mesa etching 7 is a view showing a state in which the substrate is removed from the semiconductor structure.

The method for manufacturing the semiconductor device according to the embodiment includes: by sequentially forming a main absorption layer P1, a first conductivity type semiconductor layer 124, an active layer 126 and a second conductivity type on a substrate 1 The semiconductor layer 127 forms a semiconductor structure; is placed on a channel layer 12 between a plurality of wafer regions 10 to form a light absorbing layer 13; forms a plurality of electrodes on the wafer regions 10 and the channel layer 12; and by using a Laser light is directed to the substrate 1 to separate the substrate 1 .

5a, in forming the semiconductor structure, the semiconductor structure 120 can be formed by sequentially forming the main absorption layer P1, the first conductivity type semiconductor layer 124, the active layer 126 and the second conductivity type on the substrate 1. type semiconductor layer 127 is formed.

The substrate 1 can be formed of a material selected from the following group: sapphire (Al ₂ O ₃ ), silicon carbide (SiC), gallium arsenide (GaAs), gallium nitride (GaN), zinc oxide (ZnO), silicon (Si), gallium phosphide (GaP), indium phosphide (InP) and germanium (Ge), but the invention is not limited thereto.

The main absorption layer P1 can be made of a material with a low aluminum content, and can absorb the laser light. For example, the main absorption layer P1 can be an AlGaN monolayer or a superlattice structure.

Referring to FIG. 5 a and FIG. 6 , in forming the light absorbing layer 13 , the light absorbing layer 13 can be formed on the channel layer 12 . The light absorbing layer 13 may include a material having an energy band gap sufficient to absorb a LLO laser. A wavelength range of the laser stripping laser light is not particularly limited. The light absorbing layer 13 can be ITO, but the invention is not limited thereto. For example, The light absorbing layer 13 may have the same composition as the second electrode.

In terms of forming the electrodes, the first electrodes 142, the second electrodes 246, the second conductive layer 150, the first conductive layer 165 and the conductive substrate 170 can be sequentially formed on the wafer region 10 And on the channel layer 12.

Referring to FIG. 5 b and FIG. 7 , in separating the substrate 1 , the substrate 1 can be separated from the semiconductor structure 120 by using a laser light. In this example, the main absorbing layer P1 can be separated by absorbing the laser light.

Since the light absorbing layer 13 is additionally disposed on the channel layer 12 , most of the laser light passing through the main absorbing layer P1 can be absorbed into the light absorbing layer 13 . Therefore, the electrode layers M1 , the first conductive layer 165 and the second conductive layer 150 formed on the channel layer 120 do not absorb the laser light, and thus the separation phenomenon can be improved.

Referring to FIG. 5c, the wafer regions 10 can be separated by mesa etching a surface of the semiconductor structure 120 from which the substrate 1 is removed. In this case, a part of the light absorbing layer 13 can be disposed within the wafer region 10 . However, the present invention is not limited thereto, and the semiconductor structure 120 can be etched so that the light absorbing layer 13 has no overlap in a thickness direction.

Referring to FIG. 5 d , a space between the semiconductor structures 120 separated from each other can be cut and divided into a plurality of semiconductor devices, and the passivation layer 180 can be formed on the semiconductor structures 120 and the light absorbing layer 13 .

FIG. 8 is a view showing a modified example of FIG. 6 , and FIG. 9 is a view showing a state where the substrate is removed from the semiconductor structure having the structure of FIG. 8 .

Referring to FIGS. 8 and 9 , instead of forming the light absorbing layer on the channel layer 12 , a plurality of notches 11 a and a plurality of protrusions 11 b protruding from the bottom surfaces of the notches 11 a may be formed. The protrusions 11 b can be disposed around the wafer regions 10 . In this example, even when the electrode layer M1 of the channel layer 12 absorbs the laser light and is separated, the separation can be prevented from extending to the wafer regions 10 by the protrusions 11 b. That is to say, the protruding portions 11b can be used as an anti-blocking wall to prevent the expansion of separation. However, the present invention is not limited thereto, and when the recesses 11a and the protrusions 11b are formed, a light absorbing layer may be further formed thereon.

FIG. 10 is a conceptual view of a semiconductor device according to a second embodiment of the present invention. FIGS. 11a to 11b are used to illustrate the structure of improving light output according to the change of the number of notches. view.

Referring to FIG. 10, the semiconductor device according to the second embodiment of the present invention includes: a semiconductor structure 120, which includes a first conductivity type semiconductor layer 124, an active layer 126, and a second conductivity type semiconductor layer 127; A plurality of first electrodes 142 are electrically connected to the first conductive type semiconductor layer 124 ; and a plurality of second electrodes 246 are electrically connected to the second conductive type semiconductor layer 127 .

The semiconductor structure 120 includes the first conductive type semiconductor layer 124 , the second conductive type semiconductor layer 127 and the active layer 126 disposed between the first conductive type semiconductor layer 124 and the second conductive type semiconductor layer 127 . The content described in Figure 1 can be applied to this structure.

The semiconductor structure 120 according to this embodiment includes a plurality of notches 128 . The notches 128 can be formed from a first surface 127G of the second conductive type semiconductor layer 127 through the active layer 126 to a part of the first conductive type semiconductor layer 124 .

The first electrode 142 can be disposed in the recess 128 and electrically connected to the first conductive type semiconductor layer 124 . A first conductive layer 165 can be disposed in the notches 128 to electrically connect the first electrodes 142 . A first insulating layer 131 is disposed in the recesses 128 to electrically isolate the first conductive layer 165 from the second conductive type semiconductor layer 127 and the active layer 126 .

The first insulating layer 131 may include a plurality of first openings 21 . The first electrode 142 can be disposed in the first opening 21 of the first insulating layer 131 and electrically connected to the first conductive type semiconductor layer 124 .

The first electrode 142 is preferably separated from a side surface of the notch 128 to ensure the yield and/or reliability of the semiconductor device. The first insulating layer 131 can be disposed between the first electrode 142 and the side surface of the notch 128 in the notch 128 to ensure the reliability of the semiconductor device.

Therefore, when the diameter of the recess 128 is 20 μm or more, an operating limit for disposing the first electrode 142 and the first insulating layer 131 in the recess 128 can be obtained and thus the reliability of the semiconductor device can be obtained. Spend. Furthermore, in order to obtain a proper area of the active layer 126, the notch 128 is preferably configured to have a diameter of 70 μm or less. The diameter of the notch 128 may be a maximum diameter of the notch 128 formed on the first surface 127G of the second conductive type semiconductor layer 127 .

Referring to FIG. 11A, when the semiconductor structure 120 based on gallium oxide emits ultraviolet In addition, the GaO-based semiconductor structure 120 may include aluminum, and when an aluminum content of the semiconductor structure 120 increases, a current spreading performance of the semiconductor structure 120 may become low. Furthermore, when the active layer includes aluminum and emits ultraviolet light, compared with a GaN-based blue light-emitting device (transverse magnetic field mode TM mode), it is emitted to one side surface of the active layer The total amount of light is increased. The transverse magnetic field mode can mainly occur in a UV semiconductor device.

The ultraviolet semiconductor device has a lower current spreading performance than the gallium nitride based blue light emitting device. Therefore, the ultraviolet semiconductor device requires a relatively larger number of first electrodes 142 than the GaN-based blue light emitting device.

When the aluminum content increases, the current spreading performance may decrease. Referring to FIG. 11 a , a current can be spread only around each first electrode 142 and the current density can drop significantly at a position away from the first electrode 142 . Therefore, an effective light emitting area _P2 can be reduced.

The effective light-emitting region _P2 can be defined as an area up to a boundary position whose current density is 40% or less of a central point of the first electrode 142 having the highest current density. For example, the effective light emitting region _P2 can be adjusted within a range of 40 μm from a central point of the notch according to a level of injection current and an aluminum content.

The current density in a low current density region _P3 is low, so an amount of light emitted in the low current density region _P3 may be smaller than an amount of light emitted in the effective light emitting region _P2 . Therefore, light output can be improved by additionally disposing the first electrode 142 in the low current density region _P3 with low current density or by using a reflective structure.

In general, since the GaN-based semiconductor device emitting blue light has a relatively high current spreading performance, the areas of the notch 128 and the first electrode 142 are preferably minimized. This is because as the areas of the notch 128 and the first electrode 142 increase, an area of the active layer 126 decreases. However, in this embodiment, due to the high aluminum content and relatively low current spreading performance, it is best to increase the area of the first electrode 142 and/or the second electrode 142 even when the area of the active layer 126 is reduced. The number of electrodes 142 is used to reduce an area of the low current density region P ₃ , or a reflective structure is provided in the low current density region P ₃ .

Referring to FIG. 11 b , when the number of the notches 128 is increased to 48, the notches 128 can be arranged in a zigzag pattern instead of being arranged straight in a grid pattern. In this example, due to the reduced area of the low current density region _P3 , most of the active layer 126 can participate in light emission.

When the number of the notches 128 is 70 to 110, a current can be spread more effectively, an operating voltage can be further reduced and light output can be improved. In a semiconductor device that emits UV-C, 70 or more notches 128 are preferably provided to obtain electrical and optical properties, and 110 or more notches 128 are preferably provided to obtain the active layer 126 volume and optical properties.

Referring to FIG. 10 again, the second electrodes 246 may be disposed on the first surface 127G of the second conductive type semiconductor layer 127 . The second electrode 246 may include a light-transmitting electrode that absorbs relatively less amount of ultraviolet light.

The first electrode 142 and the second electrode 246 can be ohmic electrodes. Each of the first electrode 142 and the second electrode 246 may include at least one of the following: indium tin oxide (ITO), indium zinc oxide (IZO), indium zinc tin oxide (IZTO), indium zinc aluminum oxide (IAZO) , Indium Gallium Zinc Oxide (IGZO), Indium Tin Gallium Oxide (IGTO), Zinc Aluminum Oxide (AZO), Antimony Tin Oxide (ATO), Zinc Gallium Oxide (GZO), Indium Zinc Oxide Nitride (IZON), Aluminum-Gallium Zinc Oxide (AGZO), Indium-Gallium Zinc Oxide (IGZO), Zinc Oxide (ZnO), Iridium Oxide (IrOx), Ruthenium Oxide (RuOx), Nickel Oxide (NiO), Ruthenium Oxide/Indium Tin Oxide (RuOx/ITO) , nickel/iridium oxide/gold (Ni/IrOx/Au), or nickel/iridium oxide/indium tin oxide (Ni/IrOx/Au/ITO), Ag (silver), nickel (Ni), chromium (Cr), Titanium (Ti), aluminum (Al), rhodium (Rh), palladium (Pd), iridium (Ir), tin (Sn), indium (In), ruthenium (Ru), magnesium (Mg), zinc (Zn), Platinum (Pt), gold (Au), hafnium (Hf), and the like, but the present invention is not limited to the above materials.

A third electrode 247 can be disposed under the second electrode 246 . The third electrode 247 can be disposed between the second conductive layer 150 and the second electrode 246 to improve the current injection efficiency. The third electrode 247 may be a non-light-transmitting electrode including a metal.

However, when the third electrode 247 is made of a highly conductive material, the third electrode 247 can be a light-transmitting electrode. The third electrode 247 may include: indium tin oxide (ITO), indium zinc oxide (IZO), indium zinc tin oxide (IZTO), indium zinc aluminum oxide (IAZO), indium gallium zinc oxide (IGZO), indium tin gallium oxide (IGTO), aluminum zinc oxide (AZO), antimony tin oxide (ATO), gallium zinc oxide (GZO), indium zinc oxide nitride (IZON), aluminum-gallium zinc oxide (AGZO), indium-gallium zinc oxide (IGZO) ), zinc oxide (ZnO), iridium oxide (IrOx), ruthenium oxide (RuOx), nickel oxide (NiO), ruthenium oxide/indium tin oxide (RuOx/ITO), nickel/iridium oxide/gold (Ni/IrOx/Au ), or nickel/iridium oxide/indium tin oxide (Ni/IrOx/Au/ITO), Ag (silver), nickel (Ni), chromium (Cr), titanium (Ti), aluminum (Al), rhodium (Rh ), palladium (Pd), Iridium (Ir), tin (Sn), indium (In), ruthenium (Ru), magnesium (Mg), zinc (Zn), platinum (Pt), gold (Au), hafnium (Hf) and the like, but the present invention Not limited to the above materials.

A reflective layer 248 can cover a part of the second electrode 246 and a part of the third electrode 247 . Therefore, the reflective layer 248 can reflect the light emitted from the active layer 126 to improve the light extraction rate. The reflective layer 248 may include an insulating material.

The reflective layer 248 may be composed of a first reflective layer with a first refractive index and a second reflective layer with a second refractive index. For example, the reflective layer 248 can be a distributed Bragg reflector (DBR), but the invention is not limited thereto. For example, the reflective layer 248 may have a structure in which a layer with a high refractive index and a layer with a low refractive index are stacked repeatedly. The reflective layer 248 can be an insulating material, such as HfO _x , Six _{O y} , _Six N _y , SiON, TiO _x or the like, and can include at least one of the above insulating materials.

The second conductive layer 150 can be electrically connected to the third electrodes 247 through holes disposed in the reflective layer 248 . Furthermore, the second conductive layer 150 may include a material with good adhesion to the first insulating layer 131 . For example, the second conductive layer 150 can be formed from at least one material selected from a group consisting of Cr, Al, Ti, Ni, Au, and the like or alloys thereof, and can be a single layer or multiple layers.

A portion of the second conductive layer 150 may be in contact with the first insulating layer 131 . When the second conductive layer 150 and the first insulating layer 131 are in contact with each other, a material with good adhesion is disposed between the second conductive layer 150 and the first insulating layer 131, and thus due to the The problem of reliability degradation caused by heat generated during operation of semiconductor devices can be solved.

The first insulating layer 131 can electrically isolate the first electrode 142 from the active layer 126 and the second conductive type semiconductor layer 127 . Furthermore, the first insulating layer 131 can electrically isolate the second conductive layer 150 from the first conductive layer 165 .

The first insulating layer 131 can include a plurality of first openings 21 passing through the notches 128 , and the first electrode 142 can be disposed in the first openings 21 . Furthermore, the first insulating layer 131 may include a second opening 22 for electrically connecting a second electrode pad 166 to the second conductive layer 150 . The widths of the first opening 21 and the second opening 22 can be different from each other.

The second electrode pad 166 can pass through the second opening of the first insulating layer 131 22 is electrically connected to the second conductive layer 150 and the second electrodes 246 .

The width of the second opening 22 of the first insulating layer 131 can be 60% or more of a total width of the second electrode pad 166 to obtain the electrical quality of the semiconductor device, and can be used for the second electrode pad 166. The total width of the pad 166 is 95% or less to obtain the luminous efficiency relative to the area of the semiconductor device.

For example, the width of the second opening 22 is preferably 40 μm or more to obtain the electrical quality of the semiconductor device. Since the second electrode pad 166 is not a part of providing light in an area of an upper surface of the semiconductor device, the preferred setting of the second electrode pad 166 must be able to obtain an area for a wiring process and The electrical quality of the semiconductor device is obtained.

The second electrode pad 166 used in the wiring process is preferably formed to have a width of 40 μm or more and is configured to obtain the electrical quality of the semiconductor device by current injection. Furthermore, the second electrode pad 166 for the wiring process is preferably set to have a width of 120 μm or less, so that an area of the non-light-emitting region between the semiconductor device and the semiconductor structure can be minimized.

At least one second electrode pad 166 can be provided, and the width of the second electrode pad 166 can be equivalent to a width of a single second electrode pad 166 .

Considering the width of the second electrode pad 166 , when the width of the second opening 22 is larger than 120 μm, the second conductive layer 150 may be exposed outside. When the second conductive layer 150 is exposed, the second conductive layer 150 may be exposed to external moisture or pollutants, and thus the quality of current injection is degraded. Therefore, in order not to expose the second conductive layer 150 , the width of the second opening 22 is preferably set to have a width of 120 μm or less.

The second insulating layer 132 can electrically isolate the second conductive layer 150 from the first conductive layer 165 . The first conductive layer 165 can be electrically connected to the first electrodes 142 through the second insulating layer 132 .

The first conductive layer 165 and a bonding layer 160 can be arranged according to a shape of the lower surface of the semiconductor structure 120 and a shape of the recess 128 . The first conductive layer 165 can be made of a material with high reflectivity. For example, the first conductive layer 165 may include aluminum. When the first conductive layer 165 includes aluminum, the first conductive layer 165 reflects the light emitted from the active layer 126 upward, thereby improving the light extraction efficiency.

The bonding layer 160 may include a conductive material. For example, the bonding layer 160 may include a material selected from a group consisting of: gold (gold), tin (tin), indium (indium), aluminum (aluminum), silicon (silicon), silver (silver) , nickel (nickel) and copper (copper), or one of their alloys (alloy). The bonding layer 160 can bond the semiconductor structure 120 to a substrate 170 during a laser lift-off process.

The substrate 170 can be made of a conductive material. For example, the substrate 170 may include a metal or a semiconductor material. The substrate 170 can be a metal with excellent electrical and/or thermal conductivity. In this case, the heat generated during the operation of the semiconductor device can be quickly discharged outside.

The substrate 170 may include a material selected from a group consisting of: silicon, molybdenum, tungsten, copper and aluminum or an alloy thereof . The substrate 170 can electrically connect the first conductive type semiconductor layer 124 with an external electrode.

A passivation layer 180 may be formed on the upper surface and side surfaces of the semiconductor structure 120 . The passivation layer 180 may be partially in ohmic contact with the first insulating layer 131 at a region adjacent to the second electrode 246 or under one of the second electrodes 246 .

An uneven part may be formed on the upper surface of the semiconductor structure 120 . The uneven portions are used to improve the extraction efficiency of light emitted by the semiconductor structure 120 . The uneven parts may have different average heights according to the wavelength of the ultraviolet light. The UV-C may have a height of about 300nm to 800nm, so when the average height thereof is about 500nm to 600nm, the light extraction rate may be improved.

Fig. 12 is a plan view of the semiconductor device according to the second embodiment of the present invention, Fig. 13 is a sectional view viewed along line A-A of Fig. 12, and Fig. 14 is a sectional view of a third electrode of the present invention Views, FIG. 15a is a view showing the state of the third electrode absorbing ultraviolet light, and FIG. 15b is a graph showing the reflectivity measured by different reflective layers relative to light in a 280nm wavelength band.

Referring to FIG. 12 , the third electrode 247 may be disposed between adjacent notches 128 when viewed from above. The third electrode 247 may include a plurality of holes S ₁ and the notches 128 may be disposed in the holes S ₁ .

The holes _S1 can have a ring shape or a polygonal shape, such as a triangle, a rectangle or a pentagon. However, the present invention is not limited thereto, and the holes S ₁ may have various shapes.

13, the first insulating layer 131 may include an extension 131a extending toward the first surface 127G of the second conductivity type semiconductor layer 127, and the second electrode 246 may be disposed on the second conductivity type semiconductor layer 127G. layer 127 on the first surface 127G.

A space W ₂ can be formed between the first insulating layer 131 and the second electrode 246 , and a part of the second conductive type semiconductor layer 127 can be exposed through the space W ₂ . The reflective layer 248 can be disposed in the space W ₂ and can be in contact with the second conductive type semiconductor layer 127 . When the reflective layer 248 is in contact with the second conductive type semiconductor layer 127, the reflective layer 248 is arranged to surround the second electrode 246, and thus the problem of separation between the second electrode 246 and the reflective layer 248 can be solved. And the reliability of the semiconductor device can be obtained.

The third electrode 247 can be disposed under the second electrode 246 . Furthermore, the third electrode 247 can be disposed between the second conductive layer 150 and the second electrode 246 to improve the current injection efficiency. When the second conductive layer 150 is directly connected to the second electrode 246 without connecting to the third electrode 247, due to the non-conductivity of the reflective layer 248, for sufficient current spreading, a thickness of the second electrode 246 should be Increase. When the thickness of the second electrode 246 is increased, the probability of the light emitted by the active layer 126 being absorbed by the second electrode 246 may be increased, thereby reducing the optical performance of the light emitting device.

When the thickness of the second electrode 246 is less than 1nm, the second electrode 246 is too thin to be properly placed, resulting in reduced electrical performance, and when the thickness of the second electrode 246 is greater than 15nm, a light absorption rate increases and the semiconductor device The light extraction rate can be reduced. The thickness of the third electrode 247 may be from 200 nm to 1.0 μm, but the invention is not limited thereto.

The reflective layer 248 may include a first hole 248 a exposing a part of the third electrode 247 . The exposed third electrode 247 can be electrically connected with the second conductive layer 150 .

A width of the first hole 248a may be smaller than a width W ₁ of the third electrode 247 . When the width of the first hole 248a is greater than the width W ₁ of the third electrode 247 , a space can be formed between the third electrode 247 and the reflective layer 248 , and thus the light extraction rate can be reduced.

Referring to FIG. 14, the third electrode 247 may include a first layer 247a including aluminum (Al) and a second layer 247b disposed between the second electrode 246 and the first layer 247a. between. The first layer 247a including aluminum (Al) may serve as a reflective layer that reflects UV light. However, the adhesion between aluminum (Al) and indium tin oxide (ITO) may not be sufficient to suppress heat generated during operation of the semiconductor device or caused by agglomeration or migration of other materials. separation phenomenon. Thus, the second layer 247b can be used to bond the first layer 247a to the second electrode 246 . The second layer 247b may include at least one of chromium (Cr), titanium (Ti) and nickel (Ni).

A third layer 247c can be disposed under the first layer 247a. The third layer 247c can be used to prevent the displacement of the aluminum of the first layer 247a to an adjacent layer or to bond the first layer 247a to other layers. The third layer 247c may include at least one of Ni, Ti, No, Pt, W, Au and Ni.

The third electrode 247 includes aluminum to reflect UV light, but the second layer 247b absorbs the UV light and thus light extraction efficiency may be poor. As shown in FIG. 15a, when an area of the third electrode 247 increases, the light absorption area of the second layer 247b may increase and thus the light extraction rate decreases.

Therefore, in one embodiment, a distributed Bragg reflector (DBR) 248 with high reflection of UV light can be used and thus the light extraction rate can be increased. Referring to Figure 15b, when an ITO light-transmitting electrode is used as the second electrode and a distributed Bragg mirror is used as the reflective layer, it can be seen that relative to 280nm UV light, its reflective power is higher than that of using aluminum as the reflective layer. of reflection.

However, since the distributed Bragg reflector (DBR) 248 is non-conductive, a current injection area is small and thus the thickness of the second electrode 246 should be increased to increase the current spreading efficiency. When the second electrode 246 is thickened, there is a problem that the light absorption rate of UV light increases. Therefore, in one embodiment, by using the third electrode 247 to spread a current, the thickness of the second electrode 246 can be controlled to be thin.

According to this embodiment, as the area of the third electrode 247 increases, the current spreading efficiency can be increased while the light extraction rate can be decreased. That is, a trade-off between the current spreading efficiency and the light extraction rate may occur. Therefore, an appropriate area ratio of the third electrode 247 may play an important role.

When viewed from above, the area ratio of the third electrode 247 and the reflective layer 248 can be from 1:0.8 to 1:1.3. Here, the areas of the third electrode 247 and the reflective layer 248 are from above It can be the largest area when viewing.

When the area ratio is greater than 1:0.8, the area of the reflective layer 248 can be increased and thus the light extraction rate can be improved. When the area ratio is less than 1:0.8 (for example, 1:0.6), the area of the reflective layer 248 may be reduced and thus the light extraction rate may decrease.

Furthermore, when the area ratio is less than 1:1.3, the area of the third electrode can be sufficiently obtained and thus the current spreading efficiency can be improved. When the area ratio is greater than 1:1.3, the area of the third electrode may be relatively reduced and thus the current spreading efficiency may decrease.

An area ratio of the first surface 127G of the second conductive type semiconductor layer 127 to the third electrode 247 can be from 1:0.3 to 1:0.7. When the area ratio is greater than 1:0.3, the area of the third electrode 247 can be increased and thus the current spreading efficiency can be sufficiently increased, and when the area ratio is controlled to be 1:0.7 or below, the light absorption of the third electrode 247 can be improved. When the area ratio is less than 1:0.3, the area of the third electrode 247 may decrease and thus the current spreading efficiency may decrease. Furthermore, when the area ratio is greater than 1:0.7, the light absorption area of the third electrode 247 may increase and thus the light extraction rate may decrease.

An area ratio of the first surface 127G of the second conductive type semiconductor layer 127 to the first electrode 142 can range from 1:0.08 to 1:0.15. When the area ratio is greater than 1:0.08, the area of the first electrode 142 can be increased and thus the current spreading efficiency can be sufficiently increased, and when the area ratio is controlled to be 1:0.15 or below, the light absorption of the first electrode 142 can be improved. When the area ratio is less than 1:0.08, the area of the first electrode 142 may decrease and thus the current spreading efficiency may decrease. Furthermore, when the area ratio is greater than 1:0.7, the interval between the first electrodes 142 may be reduced and thus the area of the third electrode 247 may not be sufficiently obtained. Therefore, the area of the third electrode 247 can be reduced and thus the current spreading efficiency is reduced.

The area of the third electrode 247 may be smaller than the area of the second electrode 246 . 13, the ratio of the width W ₃ of the second electrode 246 disposed between adjacent notches 128 to the width W ₁ of the third electrode 247 (W ₃ : W ₁ ) can be from 1:0.4 to 1:0.8 . When the ratio is less than 1:0.4, the area of the third electrode 247 can be reduced and thus the current spreading efficiency is reduced, and when the ratio is greater than 1:0.8, the light absorption of the third electrode 247 can be increased and thus the light extraction rate decline.

An inclination angle _θ1 of the reflective layer 248 can range from 20 degrees to 80 degrees. When the inclination angle of the reflective layer 248 is less than 20 degrees, the thickness of the reflective layer 248 may not be maintained sufficiently and thus the reflective force may be reduced. Furthermore, when the inclination angle is greater than 80 degrees, it is difficult for the second conductive layer 150 to be formed on one side surface of the reflective layer 248 .

FIG. 16 is a view showing a state where a plurality of unit electrodes surround a notch, and FIG. 17 is an enlarged view of part A of FIG. 12 .

Referring to FIG. 16, each notch 128 may be provided in a unit electrode 247-1. The third electrode 247 can be an aggregate of the unit electrodes 247 - 1 surrounding the notches 128 . The unit electrodes 247-1 can be integrally formed to share a sidewall, but the invention is not limited thereto. For example, the unit electrodes 247-1 may be separated from each other.

The ratio of the area of the notch 128 to the hole S ₁ separated by the unit electrode 247 - 1 can be from 1:2.0 to 1:5.0. When the area ratio is less than 1:2.0, the area of the reflective layer 248 can be reduced and thus the light extraction rate is reduced. When the area ratio is greater than 1:5.0, the area of the reflective layer 248 does not increase, and the area of a reflective electrode can be reduced. And thus the current spreading efficiency is lowered.

Referring to FIG. 17 , a distance d ₁ between a side surface of the third electrode 247 and a side surface of the semiconductor structure 120 may range from 1.0 μm to 10 μm. When the distance d ₁ is less than 1.0 μm, it is difficult to obtain an operating margin. Furthermore, when the distance d ₁ is greater than 10 μm, the current spreading efficiency of the side surface may decrease. However, the present invention is not limited thereto, and the third electrode 247 can be formed reaching the side surface of the semiconductor structure 120 .

Fig. 18 is a view showing a modified example of Fig. 13; Fig. 19 is a view showing a modified example of the third electrode of the present invention.

Referring to FIG. 18 , the reflective layer 248 may extend into the notches 128 along the first insulating layer 131 . According to the above structure, since the reflective layer 248 is disposed in the notches 128 , the light emitted from the active layer 126 in the transverse magnetic field mode can be reflected upward. The second insulating layer 132 can cover an extension 248 a of the reflective layer 248 extending into the recesses 128 .

Referring to FIG. 19 , the third electrode 247 may include a plurality of end portions 247b extending to the side surface of the semiconductor structure 120 and an end electrode 247-2 connecting the end portions 247b.

The edge electrode 247 - 2 can be continuously disposed along an edge of the semiconductor structure 120 . Therefore, the current spreading efficiency can be improved even at the edge. However, the present invention is not limited thereto, and the side electrode 247-2 can be divided into a plurality of parts.

Fig. 20 is a plane of a semiconductor device according to a third embodiment of the present invention As for the plane view, Fig. 21 is a sectional view viewed along the line B-B of Fig. 20.

Referring to FIG. 20 , when viewed from above, the semiconductor device may include a plurality of notches 128 and a plurality of third electrodes 247 . The third electrodes 247 can be separated from each other and each of the third electrodes 247 can be surrounded by the notches 128 . The third electrodes 247 according to the described embodiment may be arranged in areas without certain recesses 128 .

A diameter of the third electrode 247 may be larger than a diameter of the notches 128 , but the invention is not limited thereto. For example, the diameter of the third electrode 247 may be smaller than or equal to the diameter of the notches 128 . Furthermore, the third electrode 247 may have a polygonal shape when viewed from above.

Referring to FIG. 21 , the second conductive layer 150 and the second electrode 246 may be electrically connected to each other in a region where the third electrode 247 is disposed, and the second electrode 246 and the third electrode 247 may not be therein. A region where the third electrode 247 is disposed is isolated by the reflective layer 248 . Therefore, the area of the reflective layer 248 can be increased and thus the light extraction efficiency can be improved.

FIG. 22 is a cross-sectional view of a semiconductor device according to a fourth embodiment of the present invention, and FIG. 23 is an enlarged view of part B of FIG. 22 .

Referring to FIG. 22 and FIG. 23 , a plurality of third electrodes 247 may be disposed between a first notch 128 and a second notch 128 adjacent to each other. That is, only one third electrode 247 is not integrally formed between the adjacent first notches 128 and the second notches 128 , but there may be a plurality of third electrodes 247 disposed therebetween. Therefore, the current spreading efficiency can be further improved.

24 is a conceptual view of a semiconductor device according to a fifth embodiment of the present invention, FIG. 25a is an enlarged view of a part A of FIG. 24, and FIG. 25b is a partial enlarged view of a part A of FIG. 25a.

Referring to FIG. 24, the semiconductor device according to the embodiment includes: a semiconductor structure 120 including a first conductivity type semiconductor layer 124, a second conductivity type semiconductor layer 127, and an active layer 126; a plurality of first electrodes 142 , which is electrically connected to the first conductive type semiconductor layer 124 ; and a plurality of second electrodes 146 , which are electrically connected to the second conductive type semiconductor layer 127 .

The first conductive type semiconductor layer 124 , the active layer 126 and the second conductive type semiconductor layer 127 can be disposed in a first direction (a Y-axis direction). Hereinafter, the first direction (Y-axis direction), which is a thickness direction of each layer, is defined as a vertical direction, and a second direction (an X-axis direction) is perpendicular to the first direction (Y-axis direction) and is defined as a horizontal direction. The features described in FIG. 1 are applicable to a basic architecture of the semiconductor device itself.

Referring to FIG. 25 a and FIG. 25 b , a first insulating layer 131 can electrically isolate the first electrode 142 from the active layer 126 and the second conductive type semiconductor layer 127 . Furthermore, the first insulating layer 131 can electrically isolate the second electrode 146 and a second conductive layer 150 from a first conductive layer 165 . In addition, the first insulating layer 131 can be used to prevent one side surface of the active layer 126 from being oxidized during the process of the semiconductor device.

The first insulating layer 131 can be formed by at least one selected from a group consisting of the following materials: SiO ₂ , Six _{O y} , Si ₃ N ₄ , _Six N _y , SiO _x N _y , Al ₂ O ₃ , TiO _2. AlN and the like, however, the present invention is not limited thereto. The first insulating layer 131 can be formed as a single layer or multiple layers. For example, the first insulating layer 131 can be a distributed Bragg reflector (DBR), which has a multilayer structure including silicon oxide (Si oxide) or a titanium compound (Ti compound). However, the present invention is not limited thereto, and the first insulating layer 131 may have various reflective structures.

When the first insulating layer 131 performs a reflective function, the light emitted from the active layer 126 towards the side surface can be reflected upwards and thus the light extraction rate can be improved. In this example, as the number of notches 128 increases, the light extraction rate can be further improved.

A diameter W ₃ of the first electrode 142 may range from 24 μm to 50 μm. When the diameter W ₃ of the first electrode 142 satisfies the above range, it is favorable for current spreading and a large number of first electrodes 142 can be arranged. When the diameter W ₃ of the first _electrode 142 is greater than 24 μm, the current injected into the first conductivity type semiconductor layer 124 can be sufficiently obtained; The first electrodes 142 on the semiconductor layer 124 of a conductivity type can therefore obtain current spreading performance.

A diameter W ₁ of the notches 128 may range from 38 μm to 60 μm. The diameter W ₁ of the notches 128 can be defined as the widest area in the notch, which is disposed under the second conductive type semiconductor layer 127 . The diameter W ₁ of the notches 128 may be a diameter of the notches 128 disposed on a bottom surface of the second conductive type semiconductor layer 127 .

When the diameter _W1 of the recesses 128 is 38 μm or above, when forming the first electrode 142 disposed in the recess 128, it is possible to obtain an area to electrically connect the first electrode 142 to the first electrode 142. One of the operating limits of the conductive type semiconductor layer 124 . When the diameter W ₁ of the notches 128 is 60 μm or less, it is possible to avoid reducing the volume of the active layer 126 for disposing the first electrode 142 and thus possibly reducing the luminous efficiency.

An inclination angle _θ5 of the notches 128 can range from 70° to 90°. When the inclination angle _θ5 of the notches 128 satisfies the above range, it is beneficial to form the first electrode 142 on the upper surface and a large number of notches 128 can be formed.

When the inclination angle _θ5 is less than 70 degrees, an area of the removed portion of the active layer 126 may increase, but an area of a region where the first electrode 142 is disposed may decrease. Therefore, current injection performance decreases and luminous efficiency may decrease. Therefore, an area ratio of the first electrode 142 and the second electrode 146 can be adjusted using the inclination angle _θ5 of the notches 128 .

A thickness d ₂ of the first electrode 142 may be smaller than a thickness d ₃ of the first insulating layer 131 , and a distance d ₄ between the first electrode 142 and the first insulating layer 131 may be from 0 μm to 4 μm.

When the thickness d ₂ of the first electrode 142 is smaller than the thickness d ₃ of the first insulating layer 131 , when the first conductive layer 165 is placed, the degradation of the first-order coverage (step coverage property) occurs, such as detachment. , cracking or something like that can be solved. Furthermore, the first electrode 142 is separated from the first insulating layer 131 by a distance _d4 and thus the gap-filling property of the second insulating layer 132 can be improved.

The distance d ₄ between the first electrode 142 and the first insulating layer 131 can range from 0 μm to 4 μm. When the distance _d4 between the first electrode 142 and the first insulating layer 131 is 4 μm or less, the width of the first insulating layer 131 disposed on the upper surface of the recess 128 can be obtained, and the first insulating layer The obtained width of 131 can provide a current blocking function, thereby obtaining the reliability of the semiconductor device.

An upper surface 143 of the recess 128 may include: a first region d5, in which the first insulating layer 131 and the first conductive type semiconductor layer 124 are in contact with each other, a second region _d4 , The second insulating layer 132 and the first conductivity type semiconductor layer 124 are in contact with each other in the second region _d4 , and a third region d6, the first electrode 142 and the first conductivity type semiconductor layer in the third region d6 The semiconductor layers 124 are in contact with each other. The third region d6 may have the same width as the width W ₃ of the first electrode 142 .

When the first insulating layer 131 and the second insulating layer 132 are made of the same material, the first insulating layer 131 and the second insulating layer 132 may not be separated from each other by physical and/or chemical bonding. In this example, a sum of the width of the first region d5 and the width of the second region _d4 can be defined as the width of the first region d5 or the width of the second region _d4 .

When the notch 128 and the diameter W ₁ of the notch 128 have an inclination angle θ ₅ , as the width of the first region d5 increases, the width of the third region d6 becomes narrower, and as the width of the first region d5 Decrease, the width of the third region d6 can be widened.

The width of the first region d5 can be from 5 μm to 14 μm. When the width of the first region d5 is 5 μm or more, an operating margin for obtaining the first region d5 can be obtained, and thus the reliability of the semiconductor device can be improved. In the example where the width of the first region d5 exceeds 14 μm, when the notch 128 and the diameter W ₁ of the notch 128 have the inclination angle θ ₅ , the width W ₃ of the first electrode 142 can be reduced and thus the current performance can be reduced. .

Therefore, in order to make the current distribution of the semiconductor device uniform and obtain the current injection performance, the width of the third region d6 can be determined by adjusting the width of the first region d5 and the width of the second region _d4 .

Furthermore, when a total area of the notches 128 increases, an area where the second electrodes 146 can be disposed can decrease. The ratio of the total area of the first electrodes 142 to the total area of the second electrodes 146 can be determined by the above complementary relationship, and the width of the notches 128 and/or the total area of the notches 128 can be determined Freely design within the above range to optimize the current density by matching the density of electrons and holes.

A thickness of the second electrode 146 may be smaller than a thickness of the first insulating layer 131 . Therefore, the level coverage of the second conductive layer 150 and the second insulating layer 132 surrounding the second electrode 146 can be achieved, and the reliability of the semiconductor device can be improved. The second electrode 146 may be separated from the first insulating layer 131 by a first distance S ₂ of 1 μm to 4 μm. When the first distance _S2 is 1 μm or more, an operation limit can be obtained in disposing the second electrode 146 between the first insulating layers 131, and thus the electrical and optical performance and reliability of the semiconductor device can be improved . When the first distance S ₂ is 4 μm or less, the total area of a region where the second electrodes 146 are disposed can be reduced, and the operating voltage performance of the semiconductor device can be improved.

The second conductive layer 150 can cover the second electrodes 146 . Therefore, the second electrode pad 166, the second conductive layer 150 and the second electrode 146 can form an electrical channel layer (electrical channel layer).

The second conductive layer 150 can completely surround the second electrodes 146 and be in contact with a side surface and an upper surface of the first insulating layer 131 . The second conductive layer 150 can be made of a material with good adhesion to the first insulating layer 131 . The second conductive layer 150 can be formed of at least one material selected from a group consisting of Cr, Al, Ti, Ni, Au and the like or alloys thereof, and can be a single layer or multiple layers.

When the second conductive layer 150 is in contact with the side surface and the upper surface of the first insulating layer 131, the thermal and electrical stability of the second electrodes 146 can be improved. Furthermore, the second conductive layer 150 may have a function of reflecting light emitted toward a space between the first insulating layer 131 and the second electrode 146 .

The second conductive layer 150 can be disposed at the first distance _S2 between the first insulating layer 131 and the second electrode 146 . At the first distance _S2 , the second conductive layer 150 can be in contact with the side surface and an upper surface of the second electrode 146 and the side surface and an upper surface of the first insulating layer 131 . Moreover, the second conductive layer 150 and the second conductive type semiconductor layer 127 are in contact with each other to form a region in which a Schottky junction is disposed within the first distance _S2 , and Thus by forming a Schottky junction, a current can be easily spread. But the present invention is not limited thereto, and the region where the above-mentioned Schottky junction is located can be freely arranged in a structure in which a resistance between the second conductive layer 150 and the second conductive type semiconductor layer 127 is greater than A resistor between the second electrode 146 and the second conductive type semiconductor layer 127 .

The second insulating layer 132 can electrically isolate the second electrode 146 and the second conductive layer 150 from the first conductive layer 165 . The first conductive layer 165 can be electrically connected to the first electrode 142 through the second insulating layer 132 . The second insulating layer 132 and the first insulating layer 131 can be formed of the same material or of different materials.

The first conductivity type semiconductor layer 124 may include a 1-2 conductivity type semiconductor layer 124b with a relatively low aluminum content and a 1-1 conductivity type semiconductor layer 124a with a relatively high aluminum content. The aluminum content of the 1-1 conductive type semiconductor layer 124a may be from 60% to 70%, and the aluminum content of the 1-2 conductive type semiconductor layer 124b may be from 40% to 50%. The aluminum content of the 1-2 conductivity type semiconductor layer 124b may be lower than that of a well layer. The 1-2 conductive type semiconductor layer 124b is disposed adjacent to the active layer 126 . Therefore, the 1-2 with relatively low aluminum content The conductive type semiconductor layer 124b can be electrically connected to the first electrode 142 and the 1-2 conductive type semiconductor layer 124b can be in contact with the first electrode 142 .

The first electrode 142 can be disposed in the 1-2 conductive type semiconductor layer 124b. That is to say, the notch 128 is preferably formed to reach the 1-2 conductivity type semiconductor layer 124b. This is because the 1-1 conductivity type semiconductor layer 124a has a high aluminum content and relatively low current spreading performance. Therefore, the first electrode 142 can contact the 1-2 conductive type semiconductor layer 124b in the notch 128, and can form an ohmic contact.

The structure described in FIG. 1 can be applied to the second conductive layer 150 , the second electrode 146 , the second electrode pad 166 , the bonding layer 160 and the conductive substrate 170 .

26 is a graph showing an aluminum content in a thickness direction of the semiconductor device according to the fifth embodiment of the present invention.

The second conductivity type semiconductor layer 127 of the semiconductor device according to the embodiment includes aluminum in a surface layer and is in contact with the second electrode 246 . When a GaN thin film is disposed between the second conductivity type semiconductor layer 127 and the second electrode 246 for ohmic contact, there is a problem that the GaN thin film absorbs most of the light with a UV wavelength, resulting in a decrease in optical performance. . Therefore, in one embodiment, the aluminum content of the second conductive type semiconductor layer 127 needs to be adjusted to make it possible to make ohmic contact with the second electrode 246 without a GaN film.

According to this embodiment, the first conductive type semiconductor layer 124 , the active layer 126 and the second conductive type semiconductor layer 127 may all be AlGaN or AlN. However, the present invention is not limited thereto.

The active layer 126 can have a plurality of well layers 126 a and a plurality of barrier layers 126 b, and an electron blocking layer 129 can be disposed between the active layer 126 and the second conductive type semiconductor layer 127 .

The electron blocking layer 129 may have an aluminum content of 50% to 90%. When the aluminum content of the electron blocking layer 129 is less than 50%, the height of an energy barrier for blocking electrons may be insufficient and the light emitted by the active layer 126 may be absorbed by the electron blocking layer 129 . When the aluminum content is greater than 90%, the electrical performance of the semiconductor device may be reduced.

The electron blocking layer 129 may include a 1-1 segment 129a and a 1-2 segment 129b. When the 1-1 segment 129a is close to the electron blocking layer 129, its aluminum content may increase. An aluminum content of the 1-1 section 129a may range from 80% to 100%. Therefore, the 1-1 segment of the electron blocking layer 129 129a may be the portion with the highest aluminum content in the semiconductor structure. The 1-1 segment 129a may be AlGaN or AlN. The 1-1 segment 129a can also be a superlattice layer in which AlGaN and AlN are alternately arranged.

A thickness of the 1-1 segment 129a may be from 0.1 nm to 4 nm. When the first conductivity type semiconductor layer 124 is made of an N-type semiconductor, and the second conductivity type semiconductor layer 127 is made of a P-type semiconductor, in order to effectively block electrons from moving from the first conductivity type semiconductor layer 124 to the second In the second conductivity type semiconductor layer 127, the thickness of the 1-1 segment 129a may be 0.1 nm or more.

Moreover, in order to effectively obtain the injection efficiency of holes from the second conductive type semiconductor layer 127 into the active layer 126, the thickness of the 1-1 segment 129a may be 4 nm or less.

However, the present invention is not limited thereto, and the thickness of the 1-1 section 129a can be less than 0.1 nm to achieve a function of injecting holes from the second conductive type semiconductor layer 127 to the active layer 126, rather than blocking A function of electrons moving from the first conductive type semiconductor layer 124 to the second conductive type semiconductor layer 127 . Moreover, in order to obtain the blocking effect of electrons moving from the first conductive type semiconductor layer 124 to the second conductive type semiconductor layer 127 instead of the injection efficiency of holes from the second conductive type semiconductor layer 127 into the active layer 126, The thickness of the 1-1 segment 129a may be greater than 4 nm.

In an embodiment of the present invention, in order to obtain the injection efficiency of holes from the second conductivity type semiconductor layer 127 into the active layer 126 and to obtain the blocking electrons from moving from the first conductivity type semiconductor layer 124 to the second conductivity type semiconductor layer 127, the 1-1 section 129a can be set to have a thickness of 0.1 nm to 4 nm. However, when the electron blocking function or the hole injection function should be obtained alternatively, the above numerical range can be exceeded.

The 1-2 segment 129b may include an undoped segment. The 1-2 section 129b prevents a dopant from spreading on the active layer 126 .

The second conductivity type semiconductor layer 127 may include a 2-1 conductivity type semiconductor layer 127a and a 2-2 conductivity type semiconductor layer 127b. The 2-1 conductivity type semiconductor layer 127 a can be a surface region directly in contact with the second electrode 146 . The 2-2 conductivity type semiconductor layer 127b can be disposed between the electron blocking layer 129 and the 2-1 conductivity type semiconductor layer 127a.

An aluminum content of the 2-1 conductivity type semiconductor layer 127a may be smaller than that of the well layer 126a One of the aluminum content. Here, the well layer 126a may be the well layer with the lowest aluminum content among the plurality of well layers. When the aluminum content of the 2-1 conductivity type semiconductor layer 127a is higher than the aluminum content of the well layer 126a, a resistance between the 2-1 conductivity type semiconductor layer 127a and the second electrode 146 becomes high, and may not be able to achieve sufficient The ohmic contact and the current injection efficiency can be reduced.

An average aluminum content of one of the 2-1 conductive type semiconductor layers 127a may be from 1% to 35% or from 1% to 10%. When the average aluminum content is greater than 35%, sufficient ohmic contact with the second electrode may not be achieved, and when the average aluminum content is less than 1%, the average aluminum content is nearly the same as a GaN content and thus light is blocked by the 2-1 The conductive type semiconductor layer 127a absorbs.

A thickness of the 2-1 conductive type semiconductor layer 127a may be from 1 nm to 10 nm. As mentioned above, since the aluminum content of the 2-1 conductive type semiconductor layer 127a for ohmic contact is low, the 2-1 conductive type semiconductor layer 127a can absorb UV light. Therefore, from the viewpoint of light output, it is beneficial to control the thickness of the 2-1 conductive type semiconductor layer 127a to be as thin as possible.

However, when the thickness of the 2-1 conductive semiconductor layer 127a is controlled to be 1 nm or less, the 2-1 conductive semiconductor layer 127a is too thin and thus it is difficult to greatly reduce the aluminum content. Also, when its thickness is thicker than 10 nm, the total amount of absorbed light is too large and thus the light output efficiency may decrease.

A thickness of the 2-2 conductive type semiconductor layer 127b may range from 10 nm to 100 nm. For example, the thickness of the 2-2 conductive type semiconductor layer 127b may be 25 nm. When the thickness of the 2-2 conductive type semiconductor layer 127b is less than 10 nm, resistance in a horizontal direction increases and thus current injection efficiency may decrease. Furthermore, when the thickness of the 2-2 conductive type semiconductor layer 127b is greater than 100 nm, resistance in a vertical direction increases and thus current injection efficiency may decrease.

The thickness of the 2-1 conductive type semiconductor layer 127a may be smaller than the thickness of the 2-2 conductive type semiconductor layer 127b. A thickness ratio of the 2-1 conductive type semiconductor layer 127a to the 2-2 conductive type semiconductor layer 127b can be from 1:5 to 1:50. When the thickness ratio is less than 1:5, the thickness of the 2-1 conductive type semiconductor layer 127a becomes too thick and thus light output efficiency may decrease. Furthermore, when the thickness ratio is greater than 1:50, the thickness of the 2-1 conductive type semiconductor layer 127a becomes too thin. Therefore, it is difficult to reduce the aluminum content to a desired aluminum content in a thin thickness range.

The aluminum content of the 2-2 conductivity type semiconductor layer 127b may be higher than that of the well layer 126a. For example, to generate ultraviolet light, the aluminum content of the well layer 126a may be from about 30% to 50%. When the aluminum content of the 2-2 conductivity type semiconductor layer 127b is lower than the aluminum content of the well layer 126a, because the The 2-2 conductive type semiconductor layer 127b absorbs ultraviolet light, and the light extraction rate can be reduced.

An average aluminum content of one of the 2-2 conductive type semiconductor layers 127b may range from 40% to 80%. When the average aluminum content of the 2-2 conductivity type semiconductor layer 127b is less than 40%, there will be a problem that the 2-2 conductivity type semiconductor layer 127b absorbs light, and when the average aluminum content of the 2-2 conductivity type semiconductor layer 127b If it is greater than 80%, there will be a problem that the current injection efficiency will decrease. For example, the average aluminum content of the 2-2 conductive type semiconductor layer 127b may be 50%.

The aluminum content of the 2-2 conductivity type semiconductor layer 127b can be reduced in a section 127c away from the active layer 126 . In this example, a decrease in the aluminum content of the 2-1 conductivity type semiconductor layer 127a may be greater than a decrease in the aluminum content of the section 127c of the 2-2 conductivity type semiconductor layer 127b. That is, a variation rate of the aluminum content of the 2-1 conductive type semiconductor layer 127a in a thickness direction may be greater than a variation rate of the aluminum content of the 2-2 conductive type semiconductor layer 127b.

The thickness of the 2-2 conductive type semiconductor layer 127b is greater than the thickness of the 2-1 conductive type semiconductor layer 127a. However, since the aluminum content of the 2-2 conductive semiconductor layer 127b should be higher than that of the well layer 126, the aluminum content of the 2-2 conductive semiconductor layer 127b can be relatively gradually reduced. However, since the thickness of the 2-1 conductive type semiconductor layer 127a is thin and the variation range of the aluminum content is large, the reduction of the aluminum content can be relatively large.

An end point of the second conductive type semiconductor layer 127 with the lowest aluminum content may be an end point of the 2-1 conductive type semiconductor layer 127a in contact with the second electrode. In this example, the aluminum content can be from 1% to 10%. When the aluminum content is less than 1%, light absorption may increase, and when the aluminum content is greater than 10%, ohmic properties may decrease.

The end point of the second conductivity type semiconductor layer 127 at which the aluminum content is the lowest may be the end point closest to the electron blocking layer 129 . In this case, as mentioned above, the aluminum content of the electron blocking layer 129 can be from 50% to 90%. Therefore, the maximum aluminum content of one of the second conductivity type semiconductor layers 127 can be from 50% to 90%.

Therefore, the aluminum content of the second conductive type semiconductor layer 127 in the thickness direction can range from 1% to 90% or from 10% to 90%. Furthermore, a ratio of the lowest aluminum content of the second conductive type semiconductor layer 127 to the highest aluminum content of the second conductive type semiconductor layer 127 may be 1:5 or 1:90.

Figures 27a and 27b are used to illustrate the improvement of light output according to the number of notches. The view of structure, Fig. 28 is a plan view according to this semiconductor device of this fifth embodiment of the present invention, Fig. 29 is a plan view according to a semiconductor device of a sixth embodiment of the present invention, Fig. 30 is according to A plan view of a semiconductor device according to a seventh embodiment of the present invention. FIG. 31 is a plan view of a semiconductor device according to an eighth embodiment of the present invention. FIG. 32 shows a plan view of a semiconductor device according to the fifth to eighth embodiments. A graph of measured light output and power conversion efficiency (wall-plug efficiency, WPE) of the semiconductor devices of the embodiment.

Referring to FIG. 27a, when the GaN-based semiconductor structure 120 emits ultraviolet light, the GaN-based semiconductor structure 120 may include aluminum. When the aluminum content of the semiconductor structure 120 increases, the current spreading performance in the semiconductor structure 120 may decrease. Moreover, when the active layer 126 includes aluminum and emits ultraviolet light, compared with a GaN-based blue light-emitting device (transverse magnetic field mode TM mode), the amount of light incident on the side surface of the active layer 126 increases by this lateral direction. The magnetic field mode can mainly occur in a UV semiconductor device.

The UV semiconductor device has a lower current spreading performance than the GaN-based blue semiconductor device. Therefore, compared with the GaN-based blue semiconductor device, the ultraviolet light semiconductor device needs to be provided with a relatively large number of first electrodes 142 .

When the aluminum content increases, the current spreading performance may decrease. Referring to FIG. 27 a , the current can only spread around each first electrode 142 and the current density can drop significantly at a position away from the first electrode 142 . Therefore, an effective light emitting area _P2 can be reduced.

The effective light-emitting region _P2 can be defined as an area up to a boundary position whose current density is 40% or less of a central point of the first electrode 142 having the highest current density. For example, the effective light emitting region _P2 can be adjusted within a range of 40 μm from a central point of the notch according to a level of injection current and an aluminum content.

The current density in a low current density region _P3 is low, so an amount of light emitted in the low current density region _P3 may be smaller than an amount of light emitted in the effective light emitting region _P2 . Therefore, light output can be improved by additionally disposing the first electrode 142 in the low current density region _P3 with low current density or by using a reflective structure.

In general, since the GaN-based semiconductor device emitting blue light has a relatively high current spreading performance, the areas of the notch 128 and the first electrode 142 are preferably minimized. This is because as the areas of the notch 128 and the first electrode 142 increase, an area of the active layer 126 decreases. However, in this embodiment, due to the high aluminum content and relatively low current spreading performance, it is best to increase the area of the first electrode 142 and/or the second electrode 142 even when the area of the active layer 126 is reduced. The number of electrodes 142 is used to reduce an area of the low current density region P ₃ , or a reflective structure is provided in the low current density region P ₃ .

Referring to FIG. 28b, when the number of the notches 128 is increased to 48, the notches 128 can be arranged in a zigzag pattern instead of being arranged straight in a horizontal and a vertical direction. In this example, due to the reduced area of the low current density region _P3 , most of the active layer 126 can participate in light emission.

Referring to FIGS. 28 to 31, it can be seen from the figures that when the number of the notches 128 increases to 79, 96, 116 and 137 respectively, a low current density area (dotted ring area) further decreases.

Table 1 below shows the following respective measurement results in Examples 1 to 4: a total area of a semiconductor structure (ISO area), an area of a P-type ohmic electrode (a second area), an area of an N-type ohmic electrode ( - the first area), the area ratio and the number of notches.

The area (ISO area) of the semiconductor structure may be the maximum horizontal cross-sectional area including the areas of the recesses.

The area of the first electrode can be an area of an N-type ohmic electrode, and its area relative to 100% of the semiconductor structure increases as the number of notches 128 increases.

The area of the second electrode can be the area of a P-type ohmic electrode, which decreases with the increase of the number of notches 128 relative to the 100% area of the semiconductor structure.

Table 2 below shows the following respective measurement results in Examples 5 to 8: the area of a semiconductor structure (ISO area), the area of a notch, the area of a second conductivity type semiconductor layer, the area of a first conductive layer and a The area of the second electrode pad.

The area of the notches can be the entire area of the notches, and the maximum area relative to 100% of the semiconductor structure increases as the number of notches increases. Here, the area of each notch may be a maximum area in a thickness direction.

The area of the second conductive type semiconductor layer can be the entire area of the second conductive type semiconductor layer, and its area relative to 100% of the semiconductor structure decreases as the number of notches 128 increases.

The area of the first conductive layer can be the full area of the area of the first conductive layer, which The area relative to 100% of the semiconductor structure decreases as the number of notches 128 increases.

The second electrode pad is designed to have a constant area relative to 100% of the area of the semiconductor structure regardless of the number of notches.

Referring to Examples 5 to 8, it can be seen that as the number of notches 128 increases, the area of the active layer and the area of the second electrode decrease, and the total area of the notch 128 and the total area of the first electrode gradually increase.

In Examples 5 to 8, the size of the semiconductor device is the same, the size of the notch is the same, and the size of the first electrode is the same. For example, the diameter of the notches 128 is equal to 56 μm, and the diameter of the first electrodes is equal to 42 μm.

The first area where the first electrodes 142 are in contact with the first conductivity type semiconductor layer 124 may be the largest cross-sectional area of the semiconductor device 120 in a horizontal direction. 4.9% to 8.6%.

When the first area of the first electrodes 142 is 4.9% or more, sufficient current injection performance can be obtained and thus light output can be obtained, and when the first area of the first electrodes 142 is 8.6% or less, it can be obtained The active layer area and the second electrode area can thus improve voltage handling performance and light output.

Furthermore, the total area of the notches 128 is 16% to 24.6% of the maximum cross-sectional area of the semiconductor device 120 in the horizontal direction. When the total area of the notches 128 cannot satisfy the above conditions, it becomes difficult to control the total area of the first electrodes 142 to be 4.9% to 8.6% of the maximum cross-sectional area. When the semiconductor device 120 is made of AlGaN, because of the high resistance of the semiconductor device 120, the current injection performance of the current injected into the semiconductor device 120 from the outside and the current spreading performance in the semiconductor device 120 can be smaller than that of a gallium nitride-based semiconductor device 120. Therefore, when the total area of the notches in the horizontal direction is 16% or more of the maximum cross-sectional area of the semiconductor device 120, electrical characteristics due to current injection performance and current spreading can be obtained. When the total area of the notches is 24.6% or less of the maximum cross-sectional area, the volume of the active layer 126 that emits light can be obtained and thus optical properties such as light output or the like can be obtained.

The second area of the second electrodes 246 in contact with the second conductive type semiconductor layer 127 may be 41.9% to 62.6% of the maximum cross-sectional area of the semiconductor device 120 in the horizontal direction. The second area can be an entire area where the second electrode 246 is in contact with the second conductive type semiconductor layer 127 .

The second area used to obtain the voltage operation performance of the semiconductor device and the hole injection performance of the semiconductor device 120 may be 42% or more of the maximum cross-sectional area of the semiconductor device 120 in the horizontal direction. Moreover, in order to achieve a balance between the electron injection performance and hole injection performance of the semiconductor device 120 and the optical and electrical characteristics of the semiconductor device, the second area can be the maximum cross-sectional area of the semiconductor device 120 in the horizontal direction 62.6% or less.

According to the embodiments, since a surface of the second conductive type semiconductor layer in contact with the second electrode includes aluminum, the current spreading performance may be relatively reduced. Therefore, there is a need to improve the current spreading performance by increasing a contact area of the second electrode.

Referring to Fig. 32, the example 5 (#1) 100% light based on the number of the notches 128 being 79 In terms of output, the light output of Example 6 (#2) with the number of notches 128 being 96 is improved by 4% compared with Example 1. Furthermore, compared with Example 1, the light output of Example 7 (#3) in which the number of the notches 128 is increased to 116 is improved by 3%. However, it can be seen that the light output of Example 8 (#4) in which the number of the notches 128 is increased to 137 is considerably lower than that of Example 7 (#3).

Furthermore, it can be seen that the power conversion efficiency (WPE) shows the same trend as the light output. The power conversion efficiency can be output power efficiency and/or input power efficiency. For example, a horizontal dotted line E1 may be a reference point for a desired power conversion efficiency, but the present invention is not limited thereto.

The first area and the second area are inversely proportional to each other. That is, when the number of notches increases in order to increase the number of first electrodes, the area of the second electrodes decreases. In Examples 5 and 8, it can be seen that excessive reduction of the first area or the second area results in a decrease in light output.

Referring to FIG. 32, it can be seen that when the number of notches ranges from 79 to 137, the light output and power conversion efficiency are quite high.

Therefore, a ratio (first area: The second area) can be controlled within a range of 1:4.87 to 1:12.7.

When the area ratio is greater than 1:4.87, the second area relative to the first area can be sufficiently obtained. Therefore, the current injection performance of the second electrode can be improved, so a balance between electrons and holes injected into the active layer 126 can be achieved. Furthermore, the current injection performance of the semiconductor device can be improved.

For example, in Example 8, the second area is only about 41.9%, so a balance between electrons and holes injected into the active layer 126 cannot be achieved and the current injection performance of the semiconductor device may be reduced. Therefore, the light output of the semiconductor device can be reduced.

In order to obtain the first area relative to the second area, the area ratio of the two can be adjusted to be less than 1:12.7. When the area ratio is adjusted to be less than 1:12.7, the current injection performance of the first electrode can be improved, and the balance of electrons and holes injected into the active layer 126 can be obtained, and therefore the current injection performance of the semiconductor device can be improved. . For example, in Example 1, the first area is only about 4.9%, so the current injection performance may be reduced.

Furthermore, a ratio of the maximum cross-sectional area of the semiconductor structure in the horizontal direction to the areas of the notches may be 1:0.16 to 1:0.246. When the area ratio is greater than 1:0.16, it can The first area is sufficiently obtained and thus the current injection performance of the first electrode can be improved. Furthermore, when the area ratio is less than 1:0.246, the second area can be obtained and thus the current injection performance can be improved.

FIG. 33 is a conceptual view of a semiconductor device according to a ninth embodiment of the present invention, and FIG. 34 is a plan view of FIG. 33 .

Referring to FIG. 33, the configuration described above can be applied to a semiconductor structure 120 itself. The notches 128 can be configured to reach a part of the first conductive type semiconductor layer 124 and pass through the second conductive type semiconductor layer 127 and the active layer 126 .

The first electrode 142 can be disposed on the upper surface of the recess 128 and can be electrically connected to the first conductive type semiconductor layer 124 . The second electrode 146 may be formed under the second conductive type semiconductor layer 127 . The second electrode 146 can be in contact with and electrically connected to the 2-1 conductive type semiconductor layer 127a.

The 2-1 conductive type semiconductor layer 127a in contact with the second electrode 146 has an average aluminum content of 10% to 35% and thus can easily perform ohmic connection. Furthermore, when the thickness of the 2-1 conductive type semiconductor layer 127a is from 1 nm to 10 nm, the amount of light absorption can be small.

When the second electrode 146 is a metal oxide such as ITO, the 2-1 conductive type semiconductor layer 127a can be in contact with oxygen. Therefore, the aluminum disposed on the surface of the 2-1 conductive type semiconductor layer 127a can react with oxygen to form aluminum oxide. In addition, NO and nitrides thereof, oxides such _{as Ga2O3} or the like may be formed.

The second electrode pad 166 may be disposed at a corner of the semiconductor device. The second electrode pad 166 may have a concave central portion and one of its upper surfaces may have a concave portion and a convex portion. A wire (not shown) can be connected to the concave portion of the upper surface of the second electrode pad 166 . Therefore, a connection area can be enlarged and the second electrode pad 166 and the wire can be connected more firmly.

The first insulating layer 131 can electrically isolate the first electrode 142 from the active layer 126 and the second conductive type semiconductor layer 127 . Furthermore, the first insulating layer 131 can electrically isolate the second electrode 146 and the second conductive layer 150 from the first conductive layer 165 .

The semiconductor device may include a side reflective portion Z ₁ disposed at an edge thereof. The side reflection part _Z1 can be formed by protruding the second conductive layer 150 , the first conductive layer 165 and the substrate 170 in the thickness direction (a Y-axis direction). Referring to FIG. 34 , the side reflection part _Z1 may be disposed along the edge of the semiconductor device and may surround the semiconductor structure.

The second conductive layer 150 of the side reflection part _Z1 may protrude higher than the active layer 126 to reflect the light emitted upward by the active layer 126 . Therefore, even if no additional reflective layer is formed, light emitted in the horizontal direction (an X-axis direction) due to the transverse magnetic field mode (TM mode) at the outermost periphery can be reflected upward.

The inclination angle of the side reflector _Z1 can be from 90 degrees to 145 degrees. The inclination angle may be an angle formed by the second conductive layer 150 and a horizontal plane (an XZ plane). As the angle goes from 90 degrees to 145 degrees, the efficiency of reflecting light traveling upwards towards the side surface may decrease.

FIG. 35 is a conceptual view of a semiconductor device package according to an embodiment of the present invention, FIG. 36 is a plan view of a semiconductor device package according to an embodiment of the present invention, and FIG. 37 shows FIG. 36 A view of an instance after modification.

Referring to FIG. 35, the semiconductor device package may include a body 2 having a groove 3 formed therein, a semiconductor device 1 disposed on the body 2 and a pair of lead frames 5a and 5b disposed on the body 2 and is electrically connected to the semiconductor device 1. This semiconductor device 1 may include all of the above-mentioned configurations.

The body 2 may comprise a material or a coating that reflects ultraviolet light. The body 2 can be formed by stacking a plurality of layers 2a, 2b, 2c, 2d and 2e. The plurality of layers 2a, 2b, 2c, 2d and 2e may comprise the same material or different materials.

The groove 3 may be formed away from the semiconductor device to be wider, and a step portion 3 a may be formed on an inclined surface of the groove 3 .

A light-transmitting layer 4 can cover the groove 3 . The light-transmitting layer 4 can be made of glass but the invention is not limited thereto. The light-transmitting layer 4 is not particularly limited as long as it is a material that can effectively transmit ultraviolet light. An interior of the groove 3 can be an empty space.

Referring to FIG. 36, the semiconductor device can be disposed on a first lead frame 5a and can be connected to the first lead frame 5a by a second lead frame 5b and a wire. In this example, the second lead frame 5b may be disposed to surround the side surface of the first lead frame.

Referring to FIG. 37, a plurality of semiconductor devices 10a, 10b, 10c, and 10d may be provided in a semiconductor package. In this example, the lead frame may include first to fifth lead frames 5a to 5b.

A first semiconductor device 10a can be disposed on a first lead frame 5a and can be connected to a second lead frame 5b by a wire. A second semiconductor device 10b can be disposed on the second lead frame 5b and can be connected to a third lead frame 5c by a wire. A third semiconductor device 10c can be disposed on the third lead frame 5c and can be connected to a fourth lead frame 5d by a wire. A fourth semiconductor device 10d can be disposed on the fourth lead frame 5d and can be connected to a fifth lead frame 5e by a wire.

The semiconductor device can be applied to various types of light emitting elements. For example, the light emitting elements may include a sterilizing device, a hardening device, an exposure device, a lighting device, a display device and a vehicle light. That is, the semiconductor device can be applied to various electronic devices provided to provide light sources.

The sterilizing device may include the semiconductor device according to the embodiment for sterilizing a desired area. The sterilizing device can be applied to home appliances, such as water purifiers, air conditioners, refrigerators and the like, but the present invention is not limited thereto. That is, the sterilizing device can be applied to various products (eg, medical devices) that need to be sterilized.

For example, the water purifier may include a sterilizing device according to this embodiment for sterilizing flowing water. The sterilizing device can be arranged in a nozzle through which water flows or in a water outlet and emits ultraviolet light. In this case, the sterilizing device may include a waterproof structure.

The curing device may include the semiconductor device according to the embodiment, and is used for curing various liquids. The concept of the liquid can be broadly defined to include various materials cured by using ultraviolet light thereon. For example, the hardening device can harden various resins. Or the hardening device can be used in a cosmetic product, such as nail trimming.

In the exposure apparatus, a photomask having a desired pattern can be placed on a sample coated with photoresist, which is a material that reacts with light, and the desired pattern can be obtained by using ultraviolet light. into a photoresist film. For example, a semiconductor device embedded as a main part of an electronic device, a printed circuit board or a display panel can use photolithography to form a fine circuit pattern in an exposure process.

According to the embodiments, a yield of a vertical light emitting device can be improved.

Furthermore, the current spreading performance is high and thus the light output can be improved.

Furthermore, an operating voltage can be reduced.

Various advantages and effects of the present invention are not limited to the above, and can be more easily understood through the description of specific embodiments of the present invention.

While the invention has been particularly shown and described with reference to illustrative embodiments thereof, it should be understood that various changes in form and detail could be made therein without departing from the spirit and scope of the following claims. For example, each component specifically shown in these embodiments can be modified and implemented. Furthermore, all differences related to modifications and applications are to be construed as included within the scope of the invention as defined by the appended claims.

120:Semiconductor Structures

124: first conductivity type semiconductor layer

126: active layer

127: second conductivity type semiconductor layer

127G: first surface

128: notch

131: the first insulating layer

132: Second insulating layer

142: first electrode

143: upper surface

150: second conductive layer

160: bonding layer

165: the first conductive layer

166: Second electrode pad

170: Substrate

180: passivation layer

246: second electrode

Claims (10)

A semiconductor device comprising: A semiconductor structure, which includes a first conductivity type semiconductor layer, a second conductivity type semiconductor layer, an active layer arranged between the first conductivity type semiconductor layer and the second conductivity type semiconductor layer, and an active layer arranged to reach the a plurality of notches in one part of the first conductive type semiconductor layer and passing through the second conductive type semiconductor layer and the active layer; a plurality of first electrodes disposed in the recesses and electrically connected to the first conductivity type semiconductor layer; a second electrode electrically connected to the second conductivity type semiconductor layer; a third electrode disposed on the second electrode; and A reflection layer is arranged on the second electrode and the third electrode. The semiconductor device according to claim 1, wherein the reflective layer includes a first hole exposing a part of the third electrode, and a width of the first hole is smaller than a width of the third electrode. The semiconductor device according to claim 1, wherein the reflective layer comprises a first reflective layer having a first refractive index and a second reflective layer having a second refractive index. The semiconductor device according to claim 1, wherein the reflective layer is a distributed Bragg reflector. The semiconductor device according to any one of claims 1-4, wherein the area ratio of the third electrode and the reflective layer is 1:0.8 to 1:1.3. A semiconductor device comprising: A semiconductor structure, which includes a first conductivity type semiconductor layer, a second conductivity type semiconductor layer, an active layer arranged between the first conductivity type semiconductor layer and the second conductivity type semiconductor layer, and an active layer arranged to reach the a plurality of notches in one part of the first conductive type semiconductor layer and passing through the second conductive type semiconductor layer and the active layer; a plurality of first electrodes disposed in the recesses and electrically connected to the first conductivity type semiconductor layer; a second electrode electrically connected to the second conductivity type semiconductor layer; and an electron blocking layer disposed between the active layer and the second conductivity type semiconductor layer, Wherein the active layer includes a plurality of well layers and a plurality of barrier layers; The second conductivity type semiconductor layer includes a 2-1 conductivity type semiconductor layer and a 2-2 conductivity type semiconductor layer Body layer; The 2-1 conductivity type semiconductor layer is in contact with the second electrode, and the 2-2 conductivity type semiconductor layer is disposed between the electron blocking layer and the 2-1 conductivity type semiconductor layer; and The aluminum content of the 2-1 conductive type semiconductor layer is smaller than that of the well layer, and the aluminum content of the 2-2 conductive type semiconductor layer is higher than that of the well layer. The semiconductor device according to claim 6, wherein the first conductivity type semiconductor layer includes a 1-1 conductivity type semiconductor layer and a 1-2 conductivity type semiconductor layer located below the 1-1 conductivity type semiconductor layer, wherein the The aluminum content of the 1-2 conductive type semiconductor layer is lower than the aluminum content of the 1-1 conductive type semiconductor layer. The semiconductor device according to claim 6, wherein the ratio between the first area of the first electrode in contact with the first semiconductor layer and the second area of the second electrode in contact with the second semiconductor layer is 1:4.87 to 1:12.7. The semiconductor device according to claim 8, wherein the first area is 4.9% to 8.6% of a maximum cross-sectional area of the semiconductor structure in the horizontal direction. The semiconductor device according to any one of claims 6-9, wherein the thickness ratio of the 2-1 conductive type semiconductor layer to the 2-2 conductive type semiconductor layer is 1:5 to 1:50.

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