TWI692651B - Optical devices and fabrication method thereof - Google Patents

Abstract

An optical device is provided. The optical device includes a substrate including a plurality of pixel units, a dielectric layer disposed on the substrate, a patterned light-transmitting layer disposed on the dielectric layer and corresponded to the pixel units, and a plurality of continuous light-shielding layers disposed on the dielectric layer and located on the both sides of the patterned light-transmitting layer. A method for fabricating an optical device is also provided.

Description

Optical element and its manufacturing method

The invention relates to an optical element, in particular to an optical element with a collimating effect and a manufacturing method thereof.

Traditionally, as an optical element for fingerprint recognition, both sides of its collimator are provided with light shielding layers to prevent incident light from leaking to adjacent pixel regions. For example, it is one of the methods to provide multiple stacked light shielding layers on both sides of the collimator. The multi-layer stacked light shielding layer is formed by stacking black light shielding material layers and transparent material layers on top of each other. Although the manufacturing method of this shading layer is relatively simple, since the black shading material layer and the transparent material layer are arranged in a stacked manner, the light incident on the collimator may still pass through the transparent material layers on both sides Refraction or diffraction leaks to the adjacent pixel area and further interferes with the light reception of the adjacent pixel area. From this point of view, this design cannot reliably solve the problem of crosstalk interference.

Therefore, it is expected to develop an optical element and a related manufacturing method that have an ideal collimating effect and can effectively avoid cross-talk.

According to an embodiment of the invention, an optical element is provided. The optical element includes: a substrate including a plurality of pixel units; a dielectric layer disposed on the substrate; a patterned light-transmitting layer disposed on the dielectric layer and corresponding to the pixel units; and A plurality of continuous light-shielding layers are provided on the dielectric layer and located on both sides of the patterned light-transmitting layer.

According to some embodiments, the patterned light-transmitting layer includes an organic material having a light transmittance of 90% or more.

According to some embodiments, the patterned light-transmitting layer transmits light with a wavelength greater than 550 nm.

According to some embodiments, the ratio of the thickness to the width of the patterned light-transmitting layer is between 5:1 and 15:1.

According to some embodiments, the ratio of the width of the patterned light-transmitting layer to the width of the pixel unit is between 0.5:1 and 0.75:1.

According to some embodiments, the light shielding layer is continuous in the longitudinal direction.

According to some embodiments, the light-shielding layer includes an oxide layer and a light-shielding material layer, and the light-shielding material layer surrounds the oxide layer.

According to some embodiments, the light-shielding material layer includes titanium nitride, titanium-tungsten alloy, or tungsten metal.

According to some embodiments, the thickness of the light-shielding material layer is between 300 and 1,500 angstroms.

According to some embodiments, the optical element of the present invention further includes a touch glass disposed on the patterned light-transmitting layer and the continuous light-shielding layer.

According to an embodiment of the present invention, a method for manufacturing an optical element is provided. The manufacturing method includes the following steps: providing a substrate including a plurality of pixel units; forming a dielectric layer on the substrate; forming a patterned light-transmitting layer on the dielectric layer, and corresponding to the pixel units; Frankly forming a light-shielding material layer on the area between the patterned light-transmitting layers; and forming an oxide layer on the light-shielding material layer to form a plurality of continuous light-shielding layers on both sides of the patterned light-transmitting layer.

According to some embodiments, the region between the patterned light-transmitting layer and the light-shielding material layer is formed by chemical vapor deposition (CVD), physical vapor deposition (PVD), or sputtering.

According to some embodiments, before forming the light-shielding material layer, it further includes forming a barrier layer overly the region between the patterned light-transmitting layers.

According to some embodiments, after forming the oxide layer, an etch back or a chemical mechanical polishing process is further performed to form the continuous light-shielding layer on both sides of the patterned light-transmitting layer.

In the present invention, the light-shielding layers provided on both sides of the light-transmitting layer (collimator) are longitudinally continuous light-shielding layers, that is, the light-shielding layer extends in a direction perpendicular to the substrate to form a continuous shape, and does not exist in the light-shielding layer Any gap through which light penetrates. Therefore, when light enters the light-transmitting layer, the incident light will not leak from the light-shielding layers on both sides of the light-transmitting layer to the adjacent pixel units. It can enter the pixel units corresponding to the lower part more intensively, effectively improving the cross-talk phenomenon that may occur between adjacent pixels. In addition, the ratio of the thickness to the width of the light-transmitting layer defined in the present invention (for example, between 5:1 to 15:1) and the ratio of the width of the light-transmitting layer to the width of the pixel unit (for example, between 0.5:1 to 0.75:1) are all specific and appropriate ratio range, the specific size ratio relationship between this structure can not only maintain the light collimation effect, but also keep the light signal reaching the bottom of the light-transmitting layer (connecting the pixel units) to a certain appropriate The intensity actually helps to maintain the light receiving effect of the pixel unit. In addition, the present invention adopts a step-by-step process step to gradually increase the thickness of the light-transmitting layer. This method can avoid the excessively thick light-transmitting layer made by the one-time process in the subsequent processes (such as various deposition methods and chemical mechanical polishing ( CMP)) may cause the structure to fall over.

In order to make the above objects, features and advantages of the present invention more comprehensible, a preferred embodiment is described below in conjunction with the accompanying drawings, which are described in detail below.

10‧‧‧Optical components

12‧‧‧ substrate

14‧‧‧dielectric layer

16, 160‧‧‧ Patterned light-transmitting layer

18. 180‧‧‧Continuous shading layer

20‧‧‧Pixel unit

22, 220‧‧‧Direction of vertical substrate

24, 240 ‧‧‧ oxide layer

25, 250‧‧‧ barrier layer

26, 260‧‧‧ shading material layer

28‧‧‧Touch glass

30, 300‧‧‧ Patterned areas between light-transmitting layers

32, 320‧‧‧ flattening steps

34、340‧‧‧Optical structure

P‧‧‧ Width of pixel unit

t‧‧‧ Thickness of shading material layer

T‧‧‧thickness of patterned light-transmitting layer

W‧‧‧Width of patterned light-transmitting layer

Figure 1 is a schematic cross-sectional view of an optical element according to an embodiment of the present invention; Figures 2A-2E are schematic cross-sectional views of a method of manufacturing an optical element according to an embodiment of the present invention; Figures 3A-3E are based on this An embodiment of the invention is a schematic cross-sectional view of a method for manufacturing an optical element.

Please refer to FIG. 1, according to an embodiment of the present invention, an optical element 10 is provided. FIG. 1 is a schematic cross-sectional view of the optical element 10.

As shown in FIG. 1, in this embodiment, the optical element 10 includes a substrate 12, a dielectric layer 14, a patterned light-transmitting layer 16, and a plurality of continuous light-shielding layers 18. The substrate 12 includes a plurality of pixel units 20. The dielectric layer 14 is disposed on the substrate 12. The patterned light-transmitting layer 16 is disposed on the dielectric layer 14 and corresponds to the pixel unit 20. The continuous light-shielding layer 18 is disposed on the dielectric layer 14 and is located on both sides of the patterned light-transmitting layer 16.

In some embodiments, the substrate 12 may include a silicon substrate or any suitable substrate material.

In some embodiments, the dielectric layer 14 may include oxide, nitride, oxynitride, or any suitable dielectric material.

In some embodiments, the patterned light-transmitting layer 16 may include an organic material with a transmittance of more than 90%, such as an epoxy resin or a photoresist-like material with a transmittance of more than 90%.

In some embodiments, the patterned light-transmitting layer 16 can transmit light with a wavelength greater than 550 nanometers, such as green light or other visible light or non-visible light.

In some embodiments, the ratio of the thickness T and the width W of the patterned light-transmitting layer 16 is approximately 5:1 to 15:1.

In some embodiments, the ratio of the thickness T to the width W of the patterned light-transmitting layer 16 is approximately 10:1.

In some embodiments, the ratio of the width W of the patterned light-transmitting layer 16 to the width P of the pixel unit 20 is approximately 0.5:1 to 0.75:1.

In some embodiments, the ratio of the width W of the patterned light-transmitting layer 16 to the width P of the pixel unit 20 is approximately 0.5:1.

In some embodiments, the light shielding layer 18 may be longitudinally continuous. The longitudinal direction here refers to a direction 22 perpendicular to the substrate 12, that is, the light shielding layer 18 extends along the direction 22 to form a continuous state.

In some embodiments, the light shielding layer 18 includes an oxide layer 24 and a light shielding material layer 26, and the light shielding material layer 26 surrounds the oxide layer 24.

In some embodiments, the oxide layer 24 may include a high density plasma (HDP) oxide layer or a spin on glass (SOG) oxide layer.

In some embodiments, the light-shielding material layer 26 may include titanium nitride, titanium-tungsten alloy, tungsten metal, or other metal materials with good light-shielding properties.

In some embodiments, the thickness t of the light-shielding material layer 26 is approximately 300 to 1,500 angstroms.

In some embodiments, a barrier layer (not shown) is provided between the light-shielding material layer 26 and the patterned light-transmitting layer 16 to promote adhesion of the light-shielding material layer 26 and the patterned light-transmitting layer 16.

In some embodiments, the above-mentioned barrier layer may be an oxide layer with a thickness of approximately 800 to 1,000 angstroms.

In some embodiments, the optical element 10 of the present invention further includes a touch glass 28 disposed on the patterned light-transmitting layer 16 and the continuous light-shielding layer 18.

The optical element 10 of the present invention can be widely used in the field of optical identification, such as fingerprint identification.

Please refer to FIGS. 2A-2E. According to an embodiment of the present disclosure, a method for manufacturing an optical element 10 is provided. 2A-2E are schematic cross-sectional views of the method of manufacturing the optical element 10.

As shown in FIG. 2A, a substrate 12 is provided. The substrate 12 includes a plurality of pixel units 20.

In some embodiments, the substrate 12 may include a silicon substrate or any suitable substrate material.

After that, a dielectric layer 14 is formed on the substrate 12.

In some embodiments, the dielectric layer 14 may include oxide, nitride, oxynitride, or any suitable dielectric material.

After that, a light-transmitting layer (not shown) is formed on the dielectric layer 14. Next, a patterned photoresist layer (not shown) is formed on the transparent layer. After that, using the patterned photoresist layer as a mask, a lithography process is performed to form the patterned light-transmitting layer 16.

It is worth noting that the patterned light-transmitting layer 16 corresponds to the pixel unit 20.

In some embodiments, the patterned light-transmitting layer 16 may include an organic material with a transmittance of more than 90%, such as an epoxy resin or a photoresist-like material with a transmittance of more than 90%.

In some embodiments, the patterned light-transmitting layer 16 can transmit light with a wavelength greater than 550 nanometers, such as green light or other visible light or non-visible light.

In some embodiments, the ratio of the thickness T and the width W of the patterned light-transmitting layer 16 is approximately 5:1 to 15:1.

In some embodiments, the ratio of the thickness T to the width W of the patterned light-transmitting layer 16 is approximately 10:1.

In some embodiments, the ratio of the width W of the patterned light-transmitting layer 16 to the width P of the pixel unit 20 is approximately 0.5:1 to 0.75:1.

In some embodiments, the ratio of the width W of the patterned light-transmitting layer 16 to the width P of the pixel unit 20 is approximately 0.5:1.

After that, as shown in FIG. 2B, a barrier layer 25 is formed on the patterned light-transmitting layer 16 and the dielectric layer 14 between the patterned light-transmitting layers 16 by a suitable deposition method.

In some embodiments, the barrier layer 25 may be an oxide layer with a thickness of approximately 800 to 1,000 angstroms.

Thereafter, as shown in FIG. 2C, a light-shielding material layer 26 is formed on the barrier layer 25 by, for example, chemical vapor deposition (CVD), physical vapor deposition (PVD), or sputtering.

In some embodiments, the light-shielding material layer 26 may include titanium nitride, titanium-tungsten alloy, tungsten metal, or other metal materials with good light-shielding properties.

In some embodiments, the thickness t of the light-shielding material layer 26 is approximately 300 to 1,500 angstroms.

After that, an oxide layer 24 is formed on the light-shielding material layer 26 by, for example, a high-density plasma (HDP) or spin-on-glass (SOG) process, and fills the area 30 between the patterned light-transmitting layers 16, as shown in 2D The picture shows.

After that, as shown in FIG. 2E, a planarization step 32 is performed by, for example, an etch back or chemical mechanical polishing (CMP) process to form a continuous light-shielding layer 18 on both sides of the patterned transparent layer 16 At this point, the fabrication of the optical structure 34 is completed.

In some embodiments, the light shielding layer 18 may be longitudinally continuous. The longitudinal direction here refers to a direction 22 perpendicular to the substrate 12, that is, the light shielding layer 18 extends along the direction 22 to form a continuous state.

In some embodiments, a touch glass (not shown) is further disposed on the patterned light-transmitting layer 16 and the continuous light-shielding layer 18.

Please refer to FIGS. 3A-3E. According to an embodiment of the present disclosure, a method for manufacturing an optical element 10 is provided. 3A-3E are schematic cross-sectional views of the method of manufacturing the optical element 10.

As shown in FIG. 3A, the optical structure 34 shown in FIG. 2E is provided.

After that, a light-transmitting layer (not shown) is formed on the optical structure 34. Next, a patterned photoresist layer (not shown) is formed on the transparent layer. Then, using the patterned photoresist layer as a mask, a lithography process is performed to form the patterned light-transmitting layer 160.

It is worth noting that the patterned transparent layer 160 corresponds to the patterned transparent layer 16 and the pixel unit 20.

In some embodiments, the patterned light-transmitting layer 160 may include an organic material with a transmittance of more than 90%, such as an epoxy resin or a photoresist-like material with a transmittance of more than 90%.

In some embodiments, the patterned light-transmitting layer 160 can transmit light with a wavelength greater than 550 nanometers, such as green light or other visible light or non-visible light.

In some embodiments, the ratio of the thickness T and the width W of the patterned light-transmitting layer 160 is approximately 5:1 to 15:1.

In some embodiments, the ratio of the thickness T to the width W of the patterned light-transmitting layer 160 is approximately 10:1.

In some embodiments, the ratio of the width W of the patterned light-transmitting layer 160 to the width P of the pixel unit 20 is approximately 0.5:1 to 0.75:1.

In some embodiments, the ratio of the width W of the patterned light-transmitting layer 160 to the width P of the pixel unit 20 is approximately 0.5:1.

Then, as shown in FIG. 3B, a barrier layer 250 is formed on the patterned light-transmitting layer 160 and the light-shielding layer 18 between the patterned light-transmitting layer 160 by a suitable deposition method.

In some embodiments, the barrier layer 250 may be an oxide layer with a thickness of about 800 to 1,000 angstroms.

Thereafter, as shown in FIG. 3C, a light-shielding material layer 260 is formed on the barrier layer 250 by, for example, chemical vapor deposition (CVD), physical vapor deposition (PVD), or sputtering.

In some embodiments, the light-shielding material layer 260 may include titanium nitride, titanium-tungsten alloy, tungsten metal, or other metal materials with good light-shielding properties.

In some embodiments, the thickness t of the light-shielding material layer 260 is about 300 to 1,500 angstroms.

After that, an oxide layer 240 is formed on the light-shielding material layer 260 by, for example, a high-density plasma (HDP) or spin-on-glass (SOG) process, and fills the area 300 between the patterned light-transmitting layers 160, as shown in 3D The picture shows.

Then, as shown in FIG. 3E, a planarization step 320 is performed by, for example, an etch-back or chemical mechanical polishing (CMP) process to form a continuous light-shielding layer 180 on both sides of the patterned transparent layer 160, and thus, The optical structure 340 is completed.

In some embodiments, the light shielding layer 180 may be continuous in the longitudinal direction. The longitudinal direction here refers to a direction 220 perpendicular to the substrate 12, that is, the light shielding layer 180 extends along the direction 220 to form a continuous state.

In some embodiments, a touch glass (not shown) is further disposed on the patterned transparent layer 160 and the continuous light-shielding layer 180.

In the present invention, the thickness of the optical element, that is, the thickness of the light-transmitting layer (collimator) can be adjusted by repeatedly performing the above process steps.

In the present invention, the light-shielding layers provided on both sides of the light-transmitting layer (collimator) are longitudinally continuous light-shielding layers, that is, the light-shielding layer extends in a direction perpendicular to the substrate to form a continuous shape, and does not exist in the light-shielding layer Any gap through which light penetrates. Therefore, when light enters the light-transmitting layer, the incident light will not leak from the light-shielding layers on both sides of the light-transmitting layer to the adjacent pixel units. It can enter the pixel units corresponding to the lower part more intensively, effectively improving the cross-talk phenomenon that may occur between adjacent pixels. In addition, the ratio of the thickness to the width of the light-transmitting layer defined in the present invention (for example, between 5:1 to 15:1) and the ratio of the width of the light-transmitting layer to the width of the pixel unit (for example, between 0.5:1 to 0.75:1) are all specific and appropriate ratio range, the specific size ratio relationship between this structure can not only maintain the light collimation effect, but also keep the light signal reaching the bottom of the light-transmitting layer (connecting the pixel units) to a certain appropriate The intensity actually helps to maintain the light receiving effect of the pixel unit. Furthermore, the present invention adopts a step-by-step process step to gradually increase the thickness of the light-transmitting layer. This method can avoid the excessively thick light-transmitting layer produced in the one-time process in the subsequent processes (such as various deposition methods and chemical mechanical polishing ( CMP)) may cause the structure to fall over.

Although the present invention has been disclosed in several preferred embodiments as above, it is not intended to limit the present invention. Anyone with ordinary knowledge in the technical field can make any changes without departing from the spirit and scope of the present invention. And retouching, therefore, the scope of protection of the present invention shall be subject to the scope defined in the appended patent application.

10‧‧‧Optical components

12‧‧‧ substrate

14‧‧‧dielectric layer

16‧‧‧patterned transparent layer

18‧‧‧Continuous shading layer

20‧‧‧Pixel unit

22‧‧‧Vertical substrate direction

24‧‧‧Oxide layer

26‧‧‧Light-shielding material layer

28‧‧‧Touch glass

P‧‧‧Width of pixel unit

t‧‧‧ Thickness of shading material layer

T‧‧‧thickness of patterned light-transmitting layer

W‧‧‧Width of patterned light-transmitting layer

Claims (13)

An optical element includes: a substrate including a plurality of pixel units; a dielectric layer disposed on the substrate; a patterned light-transmitting layer disposed on the dielectric layer and corresponding to the pixel units, The ratio of the thickness of the patterned transparent layer to the width is from 5:1 to 15:1, and the ratio of the width of the patterned transparent layer to the width of the pixel unit is from 0.5:1 to 0.75:1 And a plurality of continuous light-shielding layers disposed on the dielectric layer and located on both sides of the patterned light-transmitting layer, wherein the light-shielding layers include an oxide layer and a light-shielding material layer, the light-shielding material layer surrounding the oxide Layer, and the light-shielding material layer includes titanium nitride, titanium-tungsten alloy, or tungsten metal. The optical element as described in item 1 of the patent application range, wherein the patterned light-transmitting layer includes an organic material having a light transmittance of 90% or more. The optical element as described in item 1 of the patent application range, wherein the patterned light-transmitting layer transmits light with a wavelength greater than 550 nm. The optical element as described in item 1 of the patent application scope, wherein the light-shielding layers are longitudinally continuous. The optical element as described in item 1 of the patent application range, wherein the thickness of the light-shielding material layer is between 300 and 1,500 angstroms. The optical element as described in item 1 of the patent application scope further includes a touch glass disposed on the patterned light-transmitting layer and the continuous light-shielding layers. An optical element manufacturing method includes: providing a substrate including a plurality of pixel units; Forming a dielectric layer on the substrate; forming a patterned light-transmitting layer on the dielectric layer and corresponding to the pixel unit, wherein the ratio of the thickness and width of the patterned light-transmitting layer is between 5:1 To 15:1, and the ratio of the width of the patterned light-transmitting layer to the width of the pixel unit is between 0.5:1 and 0.75:1; frankly forming a light-shielding material layer between the patterned light-transmitting layer Area, wherein the light-shielding material layer includes titanium nitride, titanium-tungsten alloy, or tungsten metal; and an oxide layer is formed on the light-shielding material layer to form a plurality of continuous light-shielding layers on both sides of the patterned light-transmitting layer. The method for manufacturing an optical element as described in item 7 of the patent application range, wherein the patterned light-transmitting layer includes an organic material with a transmittance of 90% or more, which transmits light with a wavelength greater than 550 nm. The method for manufacturing an optical element as described in item 7 of the patent application range, wherein the light-shielding material layer is formed between the patterned light-transmitting layers by chemical vapor deposition (CVD), physical vapor deposition (PVD) or sputtering Area. The method for manufacturing an optical element as described in item 7 of the patent application range, wherein the thickness of the light-shielding material layer is between 300 and 1,500 angstroms. According to the method for manufacturing an optical element described in Item 7 of the patent application scope, before forming the light-shielding material layer, it further includes forming a barrier layer overly the region between the patterned light-transmitting layers. The method for manufacturing an optical element as described in item 7 of the patent application scope, after forming the oxide layer, further includes performing an etch back or a chemical mechanical polishing process to form the pattern on both sides of the patterned transparent layer Wait for a continuous shading layer. The method for manufacturing an optical element as described in item 7 of the patent application range, wherein the light-shielding layers are longitudinally continuous.

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