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CN-121974293-A - Sapphire substrate with micro-nano structure and preparation method and application thereof

CN121974293ACN 121974293 ACN121974293 ACN 121974293ACN-121974293-A

Abstract

The invention provides a sapphire substrate with a micro-nano structure, and a preparation method and application thereof, and belongs to the technical field of semiconductor micro-nano processing. According to the invention, the polystyrene colloid balls are used as the mask layer, the regularly arranged grid-shaped aluminum layers are obtained by precipitation on the surface of the sapphire substrate, and the required sapphire substrate with the periodic micro-nano structure with the specific shape can be prepared by using the chromium layer as the mask plate for combined etching through adjusting the period and the aperture size of the aluminum grids.

Inventors

  • SHU LEI
  • ZHANG LI

Assignees

  • 无锡学院

Dates

Publication Date
20260505
Application Date
20260209

Claims (10)

  1. 1. The preparation method of the sapphire substrate with the micro-nano structure is characterized by comprising the following steps of: (1) Mixing polystyrene colloid sphere suspension, an organic solvent and acid liquor to obtain mixed suspension, diffusing the mixed suspension to the surface of water, and then adding a surfactant to obtain closely arranged polystyrene colloid sphere membrane suspension; (2) Transferring the closely arranged polystyrene colloid sphere membrane suspension obtained in the step (1) to the surface of a sapphire substrate to obtain the sapphire substrate paved with polystyrene colloid spheres; (3) Etching polystyrene colloid balls in the sapphire substrate obtained in the step (2) to enable gaps to exist between adjacent polystyrene colloid balls, and obtaining a structural body; (4) Plating aluminum on the surface of the structure body obtained in the step (3) to obtain a sapphire substrate deposited with an aluminum layer, wherein the thickness of the aluminum layer is smaller than that of the polystyrene colloid sphere; (5) Removing polystyrene colloid balls in the sapphire substrate deposited with the aluminum layer obtained in the step (4) by using an organic solvent to obtain a sapphire substrate containing a grid-shaped aluminum layer; (6) Depositing chromium on the surface of the sapphire substrate containing the latticed aluminum layer obtained in the step (5) to obtain the sapphire substrate with the chromium layer deposited thereon, wherein the thickness of the chromium layer is smaller than that of the aluminum layer; (7) Removing the aluminum layer in the sapphire substrate with the chromium layer deposited in the step (6) to obtain the sapphire substrate with the chromium mask structure; (8) And (5) etching the sapphire substrate with the chromium mask structure obtained in the step (7) to obtain the sapphire substrate with the micro-nano structure.
  2. 2. The method according to claim 1, wherein the polystyrene colloidal spheres in the polystyrene colloidal sphere suspension in step (1) have a diameter of 0.1 to 10 μm.
  3. 3. The method according to claim 1, wherein the polystyrene colloidal sphere suspension in step (1) has a solid content of 5 to 10wt.%.
  4. 4. The preparation method of claim 1, wherein the volume ratio of the polystyrene colloidal sphere suspension, the organic solvent and the acid solution in the step (1) is 1 (3-4): 1.
  5. 5. The preparation method of the plasma etching device according to claim 1, wherein the etching in the step (3) is plasma etching, the gas used for the plasma etching is oxygen, the flow of the oxygen is 25-35 sccm, the power of the plasma etching is 10-100W, and the time of the plasma etching is 5-30 min.
  6. 6. The method according to claim 1, wherein the thickness of the aluminum layer in the step (4) is 20-50% of the diameter of the polystyrene colloid sphere.
  7. 7. The method of claim 1, wherein the etchant used in the step (8) is a mixed solution of concentrated sulfuric acid and concentrated phosphoric acid, and the volume ratio of the concentrated sulfuric acid to the concentrated phosphoric acid is (3-5): 1.
  8. 8. The method according to claim 1, wherein the etching temperature in the step (8) is 250-300 ℃ and the etching time is 0.5-3 h.
  9. 9. The sapphire substrate with a micro-nano structure prepared by the preparation method of any one of claims 1-8.
  10. 10. Use of the sapphire substrate with micro-nano structure of claim 9 in an LED.

Description

Sapphire substrate with micro-nano structure and preparation method and application thereof Technical Field The invention belongs to the technical field of semiconductor micro-nano processing, and particularly relates to a sapphire substrate with a micro-nano structure, and a preparation method and application thereof. Background Light Emitting Diodes (LEDs) are used as a new generation of solid state lighting sources, have the advantages of high efficiency, energy conservation, environmental protection, long service life and the like, and are widely applied to the fields of display, backlight, general lighting and the like. Sapphire becomes the most mainstream substrate material for preparing gallium nitride blue light and green light LEDs at present due to the advantages of good stability, high crystal quality, relatively small lattice mismatch degree with luminescent materials and the like. However, since the refractive index of the GaN material is about 2.5 and is much higher than that of the sapphire and air, when the LED device is in operation, total reflection of the outgoing light occurs at the GaN/air interface and the GaN/sapphire interface, so that the outgoing light is limited inside the device, which greatly limits the light extraction efficiency. To overcome the above problems, imaging sapphire substrate technology has been developed. The light output efficiency of the LED device can be remarkably improved by preparing the periodic micro-nano structure with the specific morphology on the surface of the sapphire substrate. Currently, the dominant technical route for preparing patterned sapphire substrates generally includes two major steps of photolithography and dry/wet etching. However, the current mainstream technology has the problems of long production period, complex process flow and low efficiency. Therefore, how to improve the process and realize the periodic micro-nano structure with specific morphology on the basis of simplifying the process is a technical problem to be solved in the field. Disclosure of Invention The invention aims to provide a sapphire substrate with a micro-nano structure, and a preparation method and application thereof. The preparation method provided by the invention has the advantages of simple process and low cost, can prepare the required periodic micro-nano structure with specific morphology, and has more excellent structure morphology adjustability. In order to achieve the above object, the present invention provides the following technical solutions: The invention provides a preparation method of a sapphire substrate with a micro-nano structure, which comprises the following steps: (1) Mixing polystyrene colloid sphere suspension, an organic solvent and acid liquor to obtain mixed suspension, diffusing the mixed suspension to the surface of water, and then adding a surfactant to obtain closely arranged polystyrene colloid sphere membrane suspension; (2) Transferring the closely arranged polystyrene colloid sphere membrane suspension obtained in the step (1) to the surface of a sapphire substrate to obtain the sapphire substrate paved with polystyrene colloid spheres; (3) Etching polystyrene colloid balls in the sapphire substrate obtained in the step (2) to enable gaps to exist between adjacent polystyrene colloid balls, and obtaining a structural body; (4) Plating aluminum on the surface of the structure body obtained in the step (3) to obtain a sapphire substrate deposited with an aluminum layer, wherein the thickness of the aluminum layer is smaller than that of the polystyrene colloid sphere; (5) Removing polystyrene colloid balls in the sapphire substrate deposited with the aluminum layer obtained in the step (4) by using an organic solvent to obtain a sapphire substrate containing a grid-shaped aluminum layer; (6) Depositing chromium on the surface of the sapphire substrate containing the latticed aluminum layer obtained in the step (5) to obtain the sapphire substrate with the chromium layer deposited thereon, wherein the thickness of the chromium layer is smaller than that of the aluminum layer; (7) And (3) removing the aluminum layer in the sapphire substrate with the chromium layer deposited in the step (6) to obtain the sapphire substrate with the chromium mask structure. (8) And (5) etching the sapphire substrate with the chromium mask structure obtained in the step (7) to obtain the sapphire substrate with the micro-nano structure. Preferably, the polystyrene colloid spheres in the polystyrene colloid sphere suspension in the step (1) have a diameter of 0.1-10 μm. Preferably, the solid content of the polystyrene colloidal sphere suspension in the step (1) is 5-10 wt.%. Preferably, in the step (1), the volume ratio of the polystyrene colloidal sphere suspension, the organic solvent and the acid liquor is 1 (3-4): 1. Preferably, the etching in the step (3) is plasma etching, the gas for the plasma etching is oxygen, the flow of the oxygen is 25-