CN111864020A - A kind of InGaN pattern substrate template, its preparation method and application in red light Micro-LED chip - Google Patents

Abstract

The invention discloses an InGaN graphic substrate template, a preparation method thereof, and an application in a red-light Micro-LED chip. The pattern substrate template sequentially includes a substrate, a GaN layer, a template layer, a GaN hexagonal pyramid array and an InGaN hexagonal truncated truncated array; wherein: the template layer has a GaN truncated or hexagonal truncated truncated array through the template layer; The hexagonal pyramid array is obtained from the GaN circular truncated or hexagonal pyramid array; the InGaN hexagonal pyramid is coaxial with the GaN hexagonal pyramid, and completely covers the GaN hexagonal pyramid, and the InGaN hexagonal pyramid and the GaN hexagonal pyramid are on the side The walls are all {10-11} planes. The pattern substrate template has a high In component content, can directly grow indium gallium nitride-based red Micro-LEDs with an In component content of 25-35%, and significantly enhance the light extraction efficiency of the chip, and is suitable for horizontal, flip-chip and vertical chips with a variety of different structures.

Description

A kind of InGaN pattern substrate template and its preparation method and in red light Micro-LED core On-chip applications

technical field

The invention belongs to the technical field of Micro-LED chips, and in particular relates to an InGaN graphic substrate template, a preparation method thereof, and an application in a red-light Micro-LED chip.

Background technique

The ternary alloy InGaN is widely used as an InGaN quantum well in nitride light-emitting diodes. At present, blue and green LED chips have been mass-produced using InGaN quantum wells with low In composition, while red LED chips mainly use GaAs materials. The use of the same system of indium gallium nitride materials to realize red, green and blue LEDs has important application value. In order to make the light-emitting color of the LED chip reach red, the indium content in the InGaN quantum well needs to be increased to at least 25-35%. In the current technology, InGaN quantum wells are grown on the c-plane of GaN thin films. Due to the large lattice mismatch between InGaN and GaN, the higher the In content in the InGaN material, the larger the lattice mismatch ratio. With the increase of In composition, the compressive strain in InGaN quantum wells increases gradually. On the one hand, the stronger compressive strain leads to a decrease in crystal quality, which reduces the internal quantum efficiency of the chip. On the other hand, compressive strain will cause piezoelectric polarization, resulting in a built-in electric field. The built-in polarization electric field tilts the energy band of the semiconductor, the space separation of electron-hole pairs, and the reduction of wave function overlap, resulting in a decrease in luminous efficiency, The luminescence peak (absorption edge) is red-shifted, a phenomenon known as the quantum-confined Stark effect. Therefore, in the InGaN material grown on the c-plane, the higher the In composition content, the greater the compressive stress, and the more difficult the growth of the InGaN material. Generally, the maximum content of In in the InGaN composition grown on the GaN layer is about 15%, which cannot meet the requirement of the In composition in the InGaN quantum well of the red LED. Therefore, it is difficult to realize InGaN-based red LED chips in the prior art.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide an InGaN pattern substrate template, its preparation method and its application in red light Micro-LED. The InGaN layer of the InGaN pattern substrate template has an In composition content of about 20%, and the In composition content difference between the InGaN quantum well and the red light InGaN quantum well is small, and the In composition content of 25% can be directly grown on the pattern substrate template. ~35% indium gallium nitride based red micro-LED. At the same time, the air gap structure in the substrate template can significantly enhance the light extraction efficiency of the red-light Micro-LED chip, and is suitable for LED chips with various structures of horizontal structure, flip-chip structure and vertical structure.

In order to solve the above-mentioned technical problems, the present invention provides the following technical solutions:

Provided is an InGaN pattern substrate template, which sequentially includes a substrate, a GaN layer, a template layer, a GaN hexagonal pyramid array and an InGaN hexagonal pyramid array; wherein:

The template layer has a GaN truncated or hexagonal truncated array inside the template layer, and the area of the upper bottom surface of the GaN truncated or hexagonal truncated platform is larger than that of the lower bottom surface;

The GaN hexagonal pyramid array is obtained by continuing to grow GaN crystals from the GaN circular truncated truncated array or the GaN hexagonal pyramid array;

In the InGaN hexagonal pyramid array, the lower bottom surface of the InGaN hexagonal pyramid is located on the template layer, the area of the lower bottom surface is larger than that of the upper bottom surface, the axis coincides with the axis of the GaN hexagonal pyramid, and the height is greater than the height of the GaN hexagonal pyramid; The diameter of the circumcircle of the bottom surface of the hexagonal pyramid is larger than the diameter of the circumcircle of the bottom surface of the hexagonal pyramid of GaN, the six sides of the bottom surface of the InGaN hexagonal pyramid are parallel to the six sides of the bottom surface of the hexagonal pyramid of GaN, and the hexagonal pyramid of InGaN and The six sides of the GaN hexagonal pyramid sidewall are all {10-11} crystal planes.

According to the above solution, in the GaN hexagonal pyramid array, the side length of the bottom surface of the GaN hexagonal pyramid is 200-300 nm, and the height is 150-300 nm.

According to the above scheme, in the InGaN hexagonal platform array, the side length of the lower bottom surface of the InGaN hexagonal platform is 800-5000 nm, the side length of the upper bottom surface is 100-4500 nm, and the height is 800-5000 nm.

According to the above scheme, the content of In in the InGaN hexagonal pyramid is 15-20%.

According to the above scheme, in the GaN truncated or hexagonal truncated truncated array, the diameter of the lower bottom of the GaN truncated truncated or the circumscribed circle diameter of the lower bottom of the GaN hexagonal The diameter of the circumscribed circle of the bottom surface is 400-600 nm, and the distance between adjacent GaN truncated or hexagonal truncated truncated truncated pyramids is 3000-10000 nm.

According to the above solution, the array angle of the GaN truncated or hexagonal truncated array is 30°˜60°.

According to the above scheme, the substrate is a sapphire substrate, a silicon substrate or a silicon carbide substrate, and the thickness is 300-500 μm; the thickness of the GaN layer is 2000-5000 nm; the material used for the template layer is silicon dioxide or nitrogen Silicon, and the thickness of the template layer is 50-100 nm.

A preparation method of an InGaN pattern substrate template is provided, and the specific steps are as follows:

Step 1, prepare the substrate;

Step 2, growing a GaN layer on the substrate;

Step 3, depositing and growing a _SiO2 template layer on the GaN layer;

Step 4, preparing a circular truncated or hexagonal pyramid structure hole array on the template layer, wherein the area of the upper bottom surface of the circular truncated or hexagonal pyramid structure is larger than that of the lower bottom surface;

Step 5. Grow GaN crystals in the circular truncated or hexagonal pyramid structure hole array of the template layer. After filling the holes, the GaN crystal continues to grow and forms a GaN hexagonal pyramid structure on the surface of the template layer to form a GaN hexagonal pyramid array;

Step 6: Grow InGaN crystals on the surface of the template layer with the axis of the GaN hexagonal pyramid structure as the axis to obtain an InGaN hexagonal pyramid structure to form an InGaN hexagonal pyramid array, wherein the six sides of the bottom surface of the InGaN hexagonal pyramid are parallel to the bottom surface of the GaN hexagonal pyramid. Six sides, the diameter of the circumcircle of the bottom surface of the InGaN hexagonal pyramid structure is larger than the diameter of the circumcircle of the bottom surface of the GaN hexagonal pyramid structure, the InGaN hexagonal pyramid structure is higher than the GaN hexagonal pyramid structure, and the InGaN hexagonal pyramid completely covered;

Step 7: Etch the top of the InGaN hexagonal pyramid structure to expose the c-plane of the InGaN hexagonal pyramid to obtain an InGaN hexagonal pyramid structure, and then polish the upper and bottom surfaces of the InGaN hexagonal pyramid to make the c-plane of the InGaN hexagonal pyramid smooth to form a smooth platform, that is, an InGaN pattern substrate template is obtained.

According to the above solution, when the hole array in the template layer is a hexagonal pyramid structure, the six sides of the sidewall of the hexagonal pyramid structure are {10-11} crystal planes.

According to the above scheme, in the circular truncated or hexagonal truncated structure hole array, the diameter of the lower bottom surface of the truncated truncated structure or the diameter of the circumscribed circle of the lower bottom surface of the hexagonal truncated structure is 200-300 nm, and the diameter of the upper bottom surface of the circular truncated structure or the diameter of the hexagonal pyramid structure is 200-300 nm. The diameter of the circumcircle of the upper bottom surface is 400-600 nm, and the distance between the adjacent circular truncated or hexagonal truncated structures is 3000-10000 nm.

According to the above solution, in the circular truncated or hexagonal pyramid structure hole array, the array angle of the hole array is 30°˜60°.

According to the above solution, in the GaN hexagonal pyramid array, the side length of the bottom surface of the GaN hexagonal pyramid is 200-300 nm, and the height is 150-300 nm; in the InGaN hexagonal pyramid array, the side length of the bottom surface of the InGaN hexagonal pyramid is 800～5000nm, height is 800～5000nm.

According to the above scheme, the top of the InGaN hexagonal pyramid is etched away by high-temperature annealing to form an InGaN hexagonal table. The upper bottom surface of the InGaN hexagonal pyramid was obtained to obtain a smooth platform.

According to the above scheme, the side length of the smooth platform formed by the InGaN hexagonal pyramid is 100-4500 nm.

An application of the above-mentioned InGaN pattern substrate in an indium gallium nitride-based red light Micro-LED chip is provided.

According to the above scheme, the LED epitaxial layer is grown on the smooth platform at the top of the InGaN pyramid of the template, and then the template layer is etched away to form an air gap structure between the substrate and the bottom surface of the LED to prepare the electrodes of the LED chip, and package after splitting, namely An indium gallium nitride-based red light Micro-LED chip is obtained, wherein the LED epitaxial layer includes an InGaN quantum well layer, and the In content in the InGaN quantum well layer is 25-35%.

According to the above scheme, the template layer is etched away by a hydrofluoric acid solution.

According to the above scheme, the LED epitaxial layers are respectively an n-type InGaN layer, an InGaN quantum well layer, and a p-type InGaN layer.

The beneficial effects of the present invention are:

1. In the InGaN pattern substrate template provided by the present invention, there are GaN hexagonal pyramid arrays and InGaN hexagonal pyramid arrays, wherein InGaN crystals grow along the {10-11} crystal planes of GaN crystals. The surface is a semi-polar surface, and the growth of InGaN material on the semi-polar surface can effectively alleviate the compressive strain caused by lattice mismatch, and the InGaN hexagonal pyramid array has a high In composition content of about 20%; The difference between the In content of the prism and the InGaN quantum well is small, which reduces the stress generation and the lattice mismatch between the substrate and the InGaN quantum well. Therefore, on the basis of this template, the In content can be obtained as 25 ~35% of InGaN quantum wells, to obtain red light Micro-LED chips, which can be applied to LED chips of various structures of horizontal structure, flip-chip structure and vertical structure.

2. The air gap structure formed in the InGaN pattern substrate template realizes the high refractive index difference between the InGaN and the air interface, so that more light can be reflected to the top surface of the LED chip, and the light extraction efficiency of the top surface of the chip is improved; The light entering the air gap from the inclined sidewall of the GaN hexagonal pyramid has no total reflection angle, which also improves the light extraction efficiency of the bottom surface of the LED chip.

3. The formation of an air gap structure in the InGaN pattern substrate template can significantly reduce the contact surface between the LED chip and the substrate, enhance the heat dissipation and air convection performance of the substrate, thereby significantly reducing the vertical structure Micro-LED chip in the laser lift-off substrate. Thermal damage introduced in the process.

4. In the present invention, by designing a GaN hexagonal pyramid array, and then growing the InGaN crystal along the {10-11} crystal plane of the GaN crystal, the compressive strain caused by effectively alleviating the lattice mismatch is reduced, and the InGaN hexagonal with high In composition content is obtained. By precisely controlling the size of the smooth platform on the bottom surface of the InGaN hexagonal platform, the size of the red LED can be controlled, and the size of the red Micro-LED can be precisely adjusted to meet different market demands.

Description of drawings

FIG. 1 is a schematic diagram of the c(0001) plane and the {10-11} plane of the hexagonal crystal system.

FIG. 2 is a schematic diagram of a hole array fabricated on a template layer according to an embodiment of the present invention.

FIG. 3 is a schematic diagram of the hole structure of the hole array in the template layer according to Embodiment 1 of the present invention being a circular truncated structure.

FIG. 4 is a schematic diagram of the hole structure of the hole array in the template layer according to Embodiment 2 of the present invention being a hexagonal pyramid structure.

FIG. 5 is a schematic structural diagram of a GaN hexagonal pyramid array and an InGaN hexagonal pyramid array grown on a template layer according to an embodiment of the present invention.

FIG. 6 is an InGaN hexagonal pyramid grown in Example 1 of the present invention.

FIG. 7 is a schematic structural diagram of an InGaN pattern substrate template obtained after removing the top of the InGaN hexagonal pyramid grown in the embodiment of the present invention.

FIG. 8 is a schematic structural diagram of growing an LED epitaxial layer on an InGaN pattern substrate template according to an embodiment of the present invention.

FIG. 9 is a schematic view of the structure after the template layer on the InGaN pattern substrate template is removed to form an air gap structure according to an embodiment of the present invention.

10 is a schematic structural diagram of a vertical structure red light emitting diode chip prepared in Example 2 of the present invention.

In the figure: substrate 1, GaN layer 2, template layer 3, hole array 4 in the template layer, GaN frustum or hexagonal pyramid 5 grown in the hole array of the template layer, GaN hexagonal pyramid 6, InGaN hexagonal pyramid 7, InGaN Hexagonal table 8, red light Micro-LED epitaxial layer 9.

Detailed ways

The technical solutions of the present invention will be further specifically described below through specific embodiments and in conjunction with the accompanying drawings.

Example 1

A preparation method of an InGaN pattern substrate is provided, and the specific steps are as follows:

Step 1. Prepare a sapphire substrate with a thickness of 300 microns;

Step 2, growing a 1000nm thick GaN layer on the sapphire substrate;

Step 3, depositing and growing a 100nm thick _SiO2 template layer on the GaN layer;

Step 4: Prepare an array of circular frustum structure holes on the template layer that penetrates the template layer, see Figures 2 and 3 , the diameter of the upper bottom surface of the circular frustum structure is 500 nm, the diameter of the lower bottom surface is 250 nm, and the distance between adjacent holes is 10000 nm. The hole array array angle is 30°;

Step 5. Grow GaN crystals in the circular frustum structure hole array obtained in Step 4. After filling the holes, the GaN crystals continue to grow and form a GaN hexagonal pyramid structure on the surface of the template layer to form a GaN hexagonal pyramid array, wherein the height of the GaN hexagonal pyramid structure is 300nm , the six sides of the sidewall are {10-11} crystal planes;

Step 6: Grow InGaN crystals on the surface of the template layer with the axis of the GaN hexagonal pyramid structure as the axis to obtain an InGaN hexagonal pyramid structure to form an InGaN hexagonal pyramid array. The pyramid completely covers the GaN hexagonal pyramid, see Figure 5 and Figure 6, where the In content of InGaN is 18%, the bottom surface of the InGaN hexagonal pyramid is 5000nm long, the height is 5000nm, and the six sides of the sidewall are {10- 11} crystal face;

Step 7, using an in-situ annealing process to etch away the top of the InGaN hexagonal pyramid obtained in Step 6 to obtain an InGaN hexagonal pyramid, the annealing temperature is 1060° C., and the annealing is performed in a nitrogen atmosphere; then the obtained InGaN hexagonal pyramid is polished by a chemical mechanical polishing process. A smooth platform with an edge length of 4000 nm is formed on the upper bottom surface of the InGaN hexagonal pyramid, and the edge length of the upper bottom surface of the InGaN hexagonal pyramid is 4000 nm, that is, an InGaN pattern substrate template is obtained.

Using the obtained InGaN pattern substrate template to prepare a flip-chip indium gallium nitride-based red light Micro-LED, the specific steps are as follows:

Step 1. Grow the LED epitaxial layer 6 on the smooth platform on the bottom surface of the InGaN hexagonal platform in the InGaN pattern substrate template, see FIG. 8 , wherein the LED epitaxial layers are respectively n-type InGaN layers and InGaN quantum well layers with 30% In content , p-type InGaN layer;

Step 2, using hydrofluoric acid solution to etch away the SiO ₂ template layer in the InGaN pattern substrate template, forming an air gap structure between the substrate template and the bottom surface of the LED, see FIG. 9 ;

Step 3: Prepare the electrodes of the LED chip, and then package and prepare the flip-chip indium gallium nitride-based red-light Micro-LED after splitting.

Example 2

A preparation method of an InGaN pattern substrate is provided, and the specific steps are as follows:

Step 1. Prepare a sapphire substrate 1 with a thickness of 300 microns;

Step 2, growing a 1000nm thick GaN layer on the sapphire substrate;

Step 3, depositing a Si ₃ N ₄ template layer with a thickness of 100 nm on the GaN layer 2;

Step 4. Prepare a hexagonal pyramid structure hole array on the template layer, see Figures 2 and 4, wherein the hexagonal pyramid structure has a side length of 250 nm on the upper bottom surface and a side length of 125 nm on the lower bottom surface. The six sides are parallel to the {10-11} crystal plane, the spacing between adjacent hexagonal truncated truncated truncated pyramids is 10000 nm, and the array angle of the hexagonal truncated pyramid structure hole array is 30°;

Step 5. GaN crystal is grown in the hexagonal pyramid structure hole array obtained in step 4. The GaN crystal continues to grow after filling the hole and forms a GaN hexagonal pyramid structure on the surface of the template layer to form a GaN hexagonal pyramid array, wherein the height of the GaN hexagonal pyramid structure is 300nm, the six crystal planes of the sidewall are {10-11} crystal planes;

Step 6: Grow an InGaN crystal on the surface of the template layer with the axis of the GaN hexagonal pyramid structure as the axis to obtain an InGaN hexagonal pyramid structure. The six sides of the bottom surface of the InGaN hexagonal pyramid are parallel to the six sides of the bottom surface of the GaN hexagonal pyramid. Complete coverage, forming an InGaN hexagonal pyramid array, see Figure 5, where the content of In in InGaN is 18%, the side length of the bottom surface of the InGaN hexagonal pyramid is 5000nm, the height is 5000nm, and the six sides of the sidewall are {10-11} Planes;

Step 7, using an in-situ high temperature annealing process to etch away the top of the InGaN hexagonal pyramid obtained in Step 6 to obtain an InGaN hexagonal pyramid, the annealing temperature is 1050°C to 1090°C, and the annealing is performed in a nitrogen atmosphere; The upper bottom surface of the InGaN hexagonal pyramid forms a smooth platform. Referring to FIG. 7 , the side length of the upper bottom surface of the InGaN hexagonal pyramid is 4000 nm, that is, an InGaN pattern substrate template is obtained.

Using the obtained InGaN pattern substrate template to prepare a vertical structure indium gallium nitride-based red Micro-LED, the specific steps are as follows:

Step 1. Grow the LED epitaxial layer 6 on the smooth platform on the bottom surface of the InGaN hexagonal platform in the InGaN pattern substrate template, see FIG. 8 , wherein the LED epitaxial layers are respectively n-type InGaN layers and InGaN quantum well layers with 30% In content , p-type InGaN layer;

Step 2, using hydrofluoric acid solution to etch away the template layer in the InGaN pattern substrate template, and form an air gap structure between the substrate template and the bottom surface of the LED, see FIG. 9 ;

Step 3, bonding the epitaxial wafer (the epitaxial layer and the substrate are collectively referred to as the epitaxial wafer) to the silicon substrate or the copper substrate;

Step 4: irradiating the sapphire substrate with laser, peeling off the sapphire substrate, exposing the N polar surface of the chip;

Step 5: After etching off the GaN layer with an alkaline solution, the electrodes of the LED chip are prepared and packaged to prepare an indium gallium nitride-based red light Micro-LED with a vertical structure, as shown in FIG. 10 .

Claims (10)

1. An InGaN patterned substrate template is characterized by sequentially comprising a substrate, a GaN layer, a template layer, a GaN hexagonal pyramid array and an InGaN hexagonal frustum array; wherein:

a GaN circular truncated cone or hexagonal frustum array penetrating through the template layer is arranged inside the template layer, and the area of the upper bottom surface of the GaN circular truncated cone or the hexagonal frustum is larger than that of the lower bottom surface of the GaN circular truncated cone or the hexagonal frustum array;

the GaN hexagonal pyramid array is obtained by continuously growing GaN crystals on the GaN circular truncated cone or hexagonal pyramid array;

the lower bottom surface of an InGaN hexagonal frustum in the InGaN hexagonal frustum array is positioned on the template layer, the area of the lower bottom surface is larger than that of the upper bottom surface, the axis is superposed with the axis of the GaN hexagonal pyramid, and the height of the lower bottom surface is larger than that of the GaN hexagonal pyramid; the diameter of the circumscribed circle of the lower bottom surface of the InGaN hexagonal frustum pyramid is larger than that of the circumscribed circle of the bottom surface of the GaN hexagonal pyramid, six edges of the lower bottom surface of the InGaN hexagonal frustum pyramid are parallel to six edges of the bottom surface of the GaN hexagonal pyramid, and six surfaces of the sidewall of the InGaN hexagonal frustum pyramid and the sidewall of the GaN hexagonal pyramid are {10-11} crystal planes.

2. The InGaN patterned substrate template as in claim 1, wherein in the GaN hexagonal pyramid array, the side length of the bottom surface of the GaN hexagonal pyramid is 200-300 nm, and the height is 150-300 nm; in the InGaN hexagonal frustum array, the side length of the lower bottom surface of the InGaN hexagonal frustum is 800-5000 nm, the side length of the upper bottom surface of the InGaN hexagonal frustum is 100-4500 nm, and the height of the InGaN hexagonal frustum array is 800-5000 nm; in the GaN round table or hexagonal frustum array, the diameter of the lower bottom surface of the GaN round table or the diameter of a circumscribed circle of the lower bottom surface of the GaN hexagonal frustum is 200-300 nm, the diameter of the upper bottom surface of the GaN round table or the diameter of a circumscribed circle of the upper bottom surface of the GaN hexagonal frustum is 400-600 nm, and the distance between adjacent GaN round tables or hexagonal frustums is 3000-10000 nm; the array angle of the GaN truncated cone or hexagonal frustum array is 30-60 degrees.

3. An InGaN patterned substrate template as In claim 1, wherein the In content In the InGaN hexagonal frustum is 15-20%.

4. The InGaN patterned substrate template as in claim 1, wherein the substrate is a sapphire substrate, a silicon substrate, or a silicon carbide substrate, and has a thickness of 300-500 μm; the template layer is made of silicon dioxide or silicon nitride and has the thickness of 50-100 nm; the thickness of the GaN layer is 2000-5000 nm.

5. A method for preparing InGaN patterned substrate template as in any of claims 1-4, comprising the steps of:

step one, preparing a substrate;

growing a GaN layer on the substrate;

step three, depositing and growing SiO on the GaN layer₂A template layer;

preparing a circular truncated cone or hexagonal frustum structure hole array penetrating through the template layer on the template layer, wherein the area of the upper bottom surface of the circular truncated cone or hexagonal frustum structure is larger than that of the lower bottom surface;

growing GaN crystals in the hole array of the truncated cone or hexagonal frustum structure of the template layer, filling the holes with the GaN crystals, continuing to grow, and forming a GaN hexagonal pyramid structure on the surface of the template layer to form a GaN hexagonal pyramid array;

sixthly, growing InGaN crystals on the surface of the template layer by taking the axis of the GaN hexagonal pyramid structure as an axis to obtain an InGaN hexagonal pyramid structure to form an InGaN hexagonal pyramid array, wherein the hexagonal sides of the bottom surface of the InGaN hexagonal pyramid are parallel to the hexagonal sides of the bottom surface of the GaN hexagonal pyramid, the diameter of a circumscribed circle of the bottom surface of the InGaN hexagonal pyramid structure is larger than that of a circumscribed circle of the bottom surface of the GaN hexagonal pyramid structure, and the InGaN hexagonal pyramid structure is higher than that of the GaN hexagonal pyramid structure;

and seventhly, etching the top end of the InGaN hexagonal pyramid structure, exposing the c surface of the InGaN hexagonal pyramid to obtain an InGaN hexagonal frustum structure, and then polishing the upper bottom surface of the InGaN hexagonal frustum to enable the c surface of the InGaN hexagonal pyramid to be smooth and form a smooth platform, so that the InGaN graphic substrate template is obtained.

6. The method according to claim 5, wherein when the hole array in the template layer is a hexagonal frustum structure, six faces of a sidewall of the hexagonal frustum structure are {10-11} crystal faces; in the hole array with the circular truncated cone or hexagonal truncated pyramid structure, the array angle of the hole array is 30-60 degrees.

7. The method for preparing the silicon wafer according to claim 5, wherein in the hole array of the circular truncated cone or hexagonal frustum structure, the diameter of the lower bottom surface of the circular truncated cone structure or the diameter of the circumcircle of the lower bottom surface of the hexagonal frustum structure is 200-300 nm, the diameter of the upper bottom surface of the circular truncated cone structure or the diameter of the circumcircle of the upper bottom surface of the hexagonal frustum structure is 400-600 nm, and the distance between the adjacent circular truncated cone or hexagonal frustum structure is 3000-10000 nm; in the GaN hexagonal pyramid array, the side length of the bottom surface of the GaN hexagonal pyramid is 200-300 nm, and the height of the bottom surface of the GaN hexagonal pyramid is 150-300 nm; in the InGaN hexagonal frustum array, the side length of the lower bottom surface of the InGaN hexagonal frustum is 800-5000 nm, the side length of a smooth platform formed by the upper bottom surface is 100-4500 nm, and the height of the smooth platform is 800-5000 nm.

8. The preparation method of claim 5, wherein in the seventh step, the top of the InGaN hexagonal pyramid is etched away by a high temperature annealing method to form the InGaN hexagonal frustum, the annealing temperature is 1050 ℃ to 1090 ℃, the annealing is performed in a nitrogen or ammonia atmosphere, and after the annealing, the upper and lower surfaces of the InGaN hexagonal frustum are polished by a chemical mechanical polishing method to obtain a smooth platform.

9. Use of an InGaN patterned substrate template as claimed in any one of claims 1 to 4 in an InGaN-based red light Micro-LED chip.

10. The use according to claim 9, characterized in that it is in particular: growing an LED epitaxial layer on a smooth platform formed on the upper bottom surface of an InGaN hexagonal prism table of the InGaN graphic substrate template, then etching off the template layer, forming an air gap structure on the substrate and the bottom surface of the LED, preparing an electrode of the LED chip, and packaging after splitting to obtain the InGaN-based red light Micro-LED chip, wherein the LED epitaxial layer comprises an InGaN quantum well layer, and the In content of the InGaN quantum well layer is 25-35%.

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