TWI465388B - Method for manufacturing nano roughing array structure - Google Patents

Description

Nano coarsening array structure manufacturing method

The present invention relates to a method of fabricating a microstructure, and more particularly to a method of fabricating a nano-roughened array structure.

In the prior art, the application of the light-emitting diode and the solar cell is quite popular. However, when the light source of the light-emitting diode is internally generated, the light extraction efficiency output to the external air interface is low, and the light is The low photoelectric conversion efficiency of the air interface introduced into the photovoltaic surface of the solar cell is known by Snell's Law, and when light is incident on the interface of different media, reflection and refraction occur, so that the light is Cannot be effectively output or imported under different media.

In general, in order to increase the light extraction efficiency of the light-emitting diode or increase the photoelectric conversion efficiency of the solar cell, the micro-nano roughening structure is mainly formed on the light-emitting surface of the light-emitting diode or the light-incident surface of the solar cell. . Taking the light-emitting diode as an example, the micro-nano roughening structure can reduce the total reflection phenomenon of the light-emitting surface, thereby improving the light-emitting efficiency; and for the solar cell, the micro-nano roughening structure can cause the light trapping effect. To improve the photoelectric conversion efficiency.

The micro-nano roughening structure may be composed of a plurality of nano-pillars, which are generally produced by a photolithography process, and the steps are generally applied to the surface of the carrier and then placed in an oven for heating. The solvent in the photoresist is volatilized. The photomask is placed on top of it, and after being irradiated with ultraviolet rays, it is heated in an oven to harden the photoresist, and then immersed in the developing solution to remove the specific photoresist to expose the specific pattern of the lower layer to expose the exposed surface of the lower layer. Etching treatment, and finally immersed in the photoresist to remove the photoresist.

Although the structure formed by the above process can improve the phenomenon of reflection and refraction, in addition to the problems of cumbersome processing procedures and high production cost, the problem of poor uniformity of the micronized rough structure is caused. Therefore, it is necessary to provide a new method of manufacturing a micro-nano roughening structure to solve the above problems.

In view of this, the present invention provides a method for fabricating a nano-roughened array structure to improve related problems such as cumbersome processing procedures, high production cost, and poor structural uniformity existing in the prior art.

In order to achieve the foregoing object of the present invention, the present invention provides a method of fabricating a nano-roughened array structure comprising the steps of: depositing a layer of dielectric material on a layer of carrier material; depositing a metal on the layer of dielectric material a film; the dielectric material layer, the metal film, and the carrier element layer are annealed to form the metal film into a plurality of metal spherical portions, and exposing the dielectric material layer between the metal spherical portions Using the metal spherical portions as a mask to etch the exposed dielectric material layer until the carrier element layer is exposed such that the unexposed dielectric material layer forms a composite columnar array structure; The metal spheroids on the composite columnar array structure are removed to form a nano-roughened array structure.

In an embodiment of the invention, the dielectric material is selected from the group consisting of cerium oxide and cerium nitride.

In an embodiment of the invention, the metal is selected from the group consisting of silver, gold, nickel, magnesium, aluminum, zinc, chromium, iron, tin, lead, copper, platinum, cobalt, and titanium.

In an embodiment of the invention, the temperature of the annealing step ranges from 250 ° C to 310 ° C.

In an embodiment of the invention, the annealing time of the annealing step ranges from 1 minute to 30 minutes.

In an embodiment of the invention, each of the metal spheres has a diameter between 10 nm and 250 nm, preferably between 100 nm and 200 nm.

In an embodiment of the invention, the nano-roughened array structure comprises a nano-pillar array structure or a nano-convex structure.

In an embodiment of the invention, each of the nano columns of the nano-pillar array structure has a diameter between 10 nm and 250 nm, preferably between 100 nm and 200 nm.

Furthermore, the present invention further provides a method for fabricating a nano-roughened array structure, comprising the steps of: depositing a metal thin film on a carrier element layer; annealing the carrier element layer on which the metal thin film is deposited, Forming a plurality of metal spherical portions on the metal thin film and exposing the carrier element layer between the metal spherical portions; using the metal spherical portions as a mask to etch the exposed carrier element layer until a surface of the carrier element layer is formed with a height difference such that a surface of the carrier element layer forms a composite columnar array structure; and the metal spherical portions on the composite columnar array structure are removed to form a nano-rough Array structure.

Compared to the prior art, the present invention has significant advantages and advantageous effects. By the above technical means, the method for fabricating the nano-roughened array structure of the present invention has at least the following advantages and effects: the present invention is formed by annealing a carrier element layer on which a metal thin film and a dielectric material layer are deposited. A plurality of metal spherical portions are used as masks for the subsequent etching process to form a nano-roughened array structure on the surface of the carrier element layer. In addition to the simple processing procedure, the invention has the advantages of good structural uniformity and good stability, thereby reducing production costs.

In order to explain the technical content, structural features, objectives and effects of the present invention in detail, the following detailed description is given by way of example.

Please refer to FIG. 1 and FIG. 2a to FIG. 2d, which are flowcharts and a perspective view of a method for manufacturing a nano-roughened array structure according to an embodiment of the present invention, wherein the arrow diagram of FIG. 2b represents a complex number. The surface 21 of the dielectric material layer 20 of the metal spherical portion 30a is subjected to an etching process, and the manufacturing method includes the following steps:

In step S11, a layer of dielectric material 20 is deposited on a layer of carrier element 10. In one embodiment, the carrier element layer 10 is a transparent conductive oxide (TCO) film, such as an Indium Tin Oxide (ITO) film, in the structure of a solar cell or a light emitting diode. The dielectric material of the dielectric material layer 20 is selected from the group consisting of cerium oxide (SiO ₂ ) and cerium nitride (SiN). The method for depositing the dielectric material layer 20 includes electron beam evaporation, plasma chemical vapor deposition, sputtering, etc., and the thickness of the dielectric material layer 20 is between 300 nm (nm) and 600 nm. Preferably, the system is between 400 nm and 500 nm, and the definition of the optimum thickness is defined by the design requirements of the inelized roughened array structure or the thickness range etchable by the etching technique.

In step S12, a metal thin film 30 is deposited on the dielectric material layer 20. The method for depositing the metal thin film 30 is to evaporate the metal into a gaseous state by electron beam evaporation, and adhere to the dielectric material layer 20 to form a metal film 30 having good adhesion ranging from 10 nm to 30 nm. between. The metal is selected from the group consisting of silver, gold, nickel, magnesium, aluminum, zinc, chromium, iron, tin, lead, copper, platinum, cobalt, and titanium.

In step S13, the carrier element layer 10 on which the dielectric material layer 20 and the metal thin film 30 are deposited is annealed, and the metal thin film 30 is self-condensed into a plurality of metal spherical portions 30a due to cohesive force, and exposed. The layer of dielectric material between the metal spheres. The metal spherical portion 30a is formed in a manner as shown in FIGS. 3a to 3c. The annealing treatment heats the metal thin film 30 to a specific temperature higher than the recrystallization temperature and maintains the specific temperature for a while, and then The metal film 30 in FIG. 3a is gradually deformed into the metal thin film 30 in FIG. 3b due to the cohesive force, and is self-aggregated into a plurality of metal spherical portions 30a, so that the conditions mainly include temperature and During the heating time, the temperature range is between 250 ° C and 310 ° C; the heating time range is between 1 minute and 30 minutes. The self-condensed into a plurality of metal spherical portions 30a each having a diameter of between 10 nm and 250 nm, preferably between 100 nm and 200 nm.

In step S14, the metal spherical portions 30a are used as masks to etch the exposed surface 21 of the dielectric material layer 20 until the carrier element layer 10 is exposed to expose the unexposed dielectric material layer. 20 forms a composite columnar array structure 40. The metal spherical portions 30a serve as masks for resisting etching of the dielectric material layer 20 under the metal spherical portions 30a during etching to retain the metal spherical portions 30a. The layer of dielectric material 20 is. The etching method includes one of reactive ion etching (RIE) and chemical wet etching.

In step S15, the metal spherical portion 30a on the composite columnar array structure 40 is removed to form a nano-roughened array structure 20a. The removal method is to immerse the composite columnar array structure 40 in an acidic solution to dissolve the metal spherical portions 30a, wherein the acidic solution comprises nitric acid, hydrochloric acid, sulfuric acid, hydrofluoric acid, perchloric acid or a combination thereof. An acidic solution. Here, each metal element is dissolved only in a specific acidic solution. The nano-roughened array structure formed by the foregoing comprises a nano-pillar array structure or a nano-convex structure, wherein each of the nano-columns of the nano-column array structure has a diameter between 10 nm and 250 nm, The best is between 100 nm and 200 nm.

According to the manufacturing method of the above embodiment, metal silver is taken as an example, and the present invention proposes the following specific embodiments: first, a cerium oxide having a thickness of about 500 nm is deposited by an electron beam evaporation machine on an indium tin oxide film of a solar cell. A layer, and then a silver film having a thickness of about 30 nm is deposited on the ceria layer by an electron beam evaporation machine. Next, the solar cell in which the cerium oxide layer and the silver thin film are deposited is placed in a furnace tube, and annealing treatment is performed at 300 ° C for 3 minutes, at which time the silver film is self-condensed into a plurality of nanoparticles due to cohesive force. Silver spheres and simultaneously exposed to the ceria layer between the nano silver spheres. The nano silver spheres are used as a mask, and the surface of the exposed ceria layer is subjected to reactive ion etching to form a composite columnar array structure having nano silver spheres. Finally, the nano silver spheres on the composite columnar array structure are removed by immersion in nitric acid to form a nano-roughened array structure.

As described above, the nano-roughening array structure of the present invention is formed by annealing a carrier element layer on which a metal thin film and a dielectric material layer are deposited, and the metal thin film is self-condensed into a plurality of metal balls due to cohesive force. And the metal spherical portion is used as a mask, and the dielectric material layer having the metal spherical portions is etched to form a nano-roughened array structure on the surface of the carrier element layer. In addition to the simple processing procedure, the invention has the advantages of good structural uniformity and good stability, thereby reducing production costs.

While the invention has been described above in terms of the preferred embodiments, the invention is not intended to limit the invention, and the invention may be practiced without departing from the spirit and scope of the invention. The scope of protection of the present invention is therefore defined by the scope of the appended claims.

10‧‧‧ Carrier element layer

20‧‧‧ dielectric material layer

20a‧‧‧Nean roughening array structure

21‧‧‧ surface

30‧‧‧Metal film

30a‧‧‧Metal Sphere

40‧‧‧Composite columnar array structure

S11~S15‧‧‧Steps

1 is a flow chart showing the steps of a method for fabricating a nano-roughened array structure according to an embodiment of the present invention.

2a is a perspective view showing a first flow of an embodiment of a nano-roughened array structure in the embodiment of the present invention.

Figure 2b is a perspective view showing a second flow of an embodiment of the nano-roughened array structure in the embodiment of the present invention.

2c is a perspective view showing a third flow of an embodiment of the nano-roughened array structure in the embodiment of the present invention.

Fig. 2d is a perspective view showing a fourth flow of an embodiment of the nano-roughened array structure in the embodiment of the present invention.

Fig. 3a is a cross-sectional view taken along line A-A' of Fig. 2a in the embodiment of the invention.

Fig. 3b is a cross-sectional view showing a process in which the metal thin films themselves agglomerate into a plurality of metal spherical portions in Figs. 2a to 2b in the embodiment of the present invention.

Fig. 3c is a cross-sectional view taken along line B-B' of Fig. 2b in the embodiment of the present invention.

S11~S15. . . step

Claims (14)

A method for fabricating a nano-roughened array structure, comprising the steps of: forming a transparent conductive oxide film of a solar cell or a transparent conductive oxide film of a light-emitting diode as a carrier element layer; depositing a layer on the carrier element layer a dielectric material layer; depositing a metal film on the dielectric material layer; the dielectric material layer, the metal film, and the carrier element layer having the transparent conductive oxide film at a temperature ranging from 250 ° C to 310 ° C Annealing treatment to form a plurality of metal spherical portions of the metal thin film and exposing the dielectric material layer between the metal spherical portions; using the metal spherical portions as a mask to expose the exposed The dielectric material layer is etched until the carrier element layer is exposed such that the unexposed dielectric material layer forms a composite columnar array structure; and the metal spheroids on the composite columnar array structure are removed To form a nano-roughened array structure. The manufacturing method according to claim 1, wherein the dielectric material is selected from the group consisting of cerium oxide and cerium nitride. The manufacturing method of claim 1, wherein the metal is selected from the group consisting of silver, gold, nickel, magnesium, aluminum, zinc, chromium, iron, tin, lead, copper, platinum, cobalt. And the group of titanium. Manufacturing as described in claim 1 The method wherein the step of depositing the layer of dielectric material is selected from the group consisting of electron beam evaporation, plasma chemical vapor deposition, and sputtering. The manufacturing method according to claim 1, wherein the step of depositing the metal thin film comprises using an electron beam evaporation method. The manufacturing method of claim 1, wherein the annealing step has a heating time ranging from 1 minute to 30 minutes. The manufacturing method of claim 1, wherein each of the metal spherical portions has a diameter of between 10 nanometers (nm) and 250 nm. The manufacturing method of claim 7, wherein each of the metal spherical portions has a diameter of between 100 nm and 200 nm. The manufacturing method according to claim 1, wherein the step of etching the exposed dielectric material layer comprises using one of a reactive ion etching method and a chemical wet etching method. The manufacturing method according to claim 1, wherein in the step of removing the metal spherical portions on the composite columnar array structure, the composite columnar array structure is immersed in an acidic solution to Dissolving the metal spheres. The manufacturing method of claim 1, wherein the nano-roughened array structure comprises a nano-pillar array structure or a nano-convex structure. The manufacturing method of claim 11, wherein each of the nano columns of the nano-pillar array structure has a diameter of between 10 nm and 250 nm. The manufacturing method of claim 12, wherein each of the nano columns of the nano-pillar array structure has a diameter of between 100 nm and 200 nm. A method for fabricating a nano-roughened array structure, comprising the steps of: forming a transparent conductive oxide film of a solar cell or a transparent conductive oxide film of a light-emitting diode as a carrier element layer; depositing a layer on the carrier element layer a metal thin film; the carrier element layer with the transparent conductive oxide film deposited on the metal film is annealed at a temperature ranging from 250 ° C to 310 ° C to form the metal thin film into a plurality of metal spherical portions, And exposing the carrier element layer between the metal spherical portions; using the metal spherical portions as a mask to etch the exposed carrier element layer until a height difference is generated on the surface of the carrier element layer, so that The surface of the carrier element layer forms a composite columnar array structure; and the metal spheroids on the composite columnar array structure are removed to form a nano-roughened array structure.