Patterned substrate, light emitting diode and preparation method thereof

Abstract

The invention discloses a patterned substrate, a light emitting diode and a preparation method thereof, and belongs to the technical field of semiconductors. The patterned substrate comprises a substrate body, a plurality of first protrusions and a plurality of second protrusions are located on the surface of the substrate body, the first protrusions are arranged at intervals to form a plurality of first hexagons, and the second protrusions are arranged at intervals to form a plurality of second hexagons. Each second hexagon is positioned in one first hexagon; the first protrusion and the second protrusion are both in a conical shape, the height of the first protrusion is larger than that of the second protrusion, and the diameter of the bottom face of the first protrusion is larger than that of the bottom face of the second protrusion.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of semiconductor technology, and in particular, to a patterned substrate, a light emitting diode and a preparation method thereof. BACKGROUND

[0002] A light emitting diode (LED) is a kind of semiconductor electronic component capable of emitting light.

[0003] In the related art, a light emitting diode generally comprises a substrate and an epitaxial structure on the substrate. The substrate is usually a patterned substrate, that is, the surface of the substrate is formed with a plurality of protrusions arranged in an array to improve the light emitting efficiency of the light emitting diode.

[0004] However, the patterned substrate in the related art still has room for further optimization in improving the light emitting efficiency of the light emitting diode. SUMMARY

[0005] Embodiments of the present disclosure provide a patterned substrate, a light emitting diode and a preparation method thereof, which can further enhance the improvement of the light emitting efficiency of the light emitting diode by the patterned substrate. The technical solutions are as follows:

[0006] In a first aspect, a patterned substrate is provided, which comprises a substrate body, a plurality of first protrusions and a plurality of second protrusions on the surface of the substrate body, the plurality of first protrusions are arranged at intervals to form a plurality of first hexagons, the plurality of second protrusions are arranged at intervals to form a plurality of second hexagons, and each of the second hexagons is located within one of the first hexagons.

[0007] The first protrusions and the second protrusions are both conical, the height of the first protrusion is greater than the height of the second protrusion, and the base diameter of the first protrusion is greater than the base diameter of the second protrusion.

[0008] Optionally, two adjacent first hexagons in the plurality of first hexagons share two vertices, and the overlapping part of the two adjacent first hexagons is a parallelogram.

[0009] Two adjacent second hexagons in the plurality of second hexagons share one side.

[0010] Optionally, the distance between the six vertices of the second hexagon and the center of the first hexagon is equal.

[0011] Optionally, the distance between any vertex of the second hexagon and the center of the first hexagon is equal to the distance between the vertex and the nearest side of the first hexagon.

[0012] Optionally, the height of the first protrusion is 1.7-2.0 μm, and the diameter of the bottom surface of the first protrusion is 2.7-2.9 μm.

[0013] Optionally, the height of the second protrusion is 0.5-0.8 μm, and the diameter of the bottom surface of the second protrusion is 0.5-0.8 μm.

[0014] Optionally, the thickness of the substrate body is 600-700 μm.

[0015] In a second aspect, a light emitting diode is provided, which comprises the patterned substrate according to the first aspect and an epitaxial structure on the patterned substrate.

[0016] In a third aspect, a method for preparing a patterned substrate is provided, which comprises:

[0017] providing a substrate;

[0018] forming a mask layer on the substrate;

[0019] performing a patterning process on the substrate with the mask layer to obtain the patterned substrate, the patterned substrate comprising a substrate body, a plurality of first protrusions and a plurality of second protrusions on the surface of the substrate body, the plurality of first protrusions being arranged in a plurality of first hexagons, the plurality of second protrusions being arranged in a plurality of second hexagons, each of the second hexagons being located in one of the first hexagons; the first protrusions and the second protrusions are both conical, the height of the first protrusions is greater than the height of the second protrusions, and the diameter of the bottom surface of the first protrusions is greater than the diameter of the bottom surface of the second protrusions.

[0020] In a fourth aspect, a method for preparing a light emitting diode is provided, which comprises:

[0021] obtaining a patterned substrate by using the method for preparing a patterned substrate according to the third aspect;

[0022] growing an epitaxial structure on the patterned substrate.

[0023] The technical scheme provided by the embodiments of the present disclosure has the following beneficial effects:

[0024] In the embodiments of the present disclosure, the plurality of first protrusions arranged in first hexagons are arranged on the surface of the substrate body, the arrangement of the first protrusions reduces the proportion of the natural growth surface of the substrate, thereby reducing the epitaxial growth defects and improving the epitaxial light emission brightness. Further, the second hexagons are arranged inside the first hexagons, the protrusions at the vertices of the second hexagons are smaller and occupy the part of the surface of the substrate body not occupied by the first protrusions, further reducing the proportion of the natural growth surface of the substrate and improving the epitaxial light emission brightness.

[0025] Meanwhile, the first protrusion and the second protrusion are both in a conical structure and are spaced apart, and the first protrusion and the second protrusion can further increase the light reflection rate of the patterned substrate, improve the light-emitting brightness of the light-emitting diode chip, and finally improve the light-emitting efficiency of the LED. BRIEF DESCRIPTION OF DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, the drawings needed to be used in the embodiments will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present disclosure, and other drawings can be obtained by those skilled in the art without creative labor.

[0027] Figure 1 is a structural schematic diagram of a patterned substrate provided by an embodiment of the present disclosure;

[0028] Figure 2 is a top view of a patterned substrate provided by an embodiment of the present disclosure;

[0029] Figure 3 is a structural schematic diagram of a light-emitting diode provided by an embodiment of the present disclosure;

[0030] Figure 4 is a flowchart of a preparation method of a patterned substrate provided by an embodiment of the present disclosure;

[0031] Figure 5 is a flowchart of a preparation method of a light-emitting diode provided by an embodiment of the present disclosure.

[0032] The following are the signs of the drawings:

[0033] 10: patterned substrate;

[0034] 11: substrate body;

[0035] 12: first protrusion;

[0036] 13: second protrusion;

[0037] 100: first hexagon;

[0038] 200: second hexagon;

[0039] 20: epitaxial structure;

[0040] 21: first semiconductor layer;

[0041] 22: active layer;

[0042] 23: second semiconductor layer;

[0043] 24: PVD layer;

[0044] 25: buffer layer;

[0045] 26: undoped layer. DETAILED DESCRIPTION

[0046] For the purpose of making the object, technical scheme and advantages of the present disclosure more clear, the present disclosure embodiments will be further described in detail below with reference to the drawings.

[0047] Figure 1 is a structural schematic diagram of a patterned substrate provided by an embodiment of the present disclosure, as shown in the figure, the patterned substrate 10 comprises a substrate body 11, a plurality of first protrusions 12 and a plurality of second protrusions 13 on the surface of the substrate body 11. Figure 1

[0048] Figure 2 is a top view of a patterned substrate provided by an embodiment of the present disclosure, Figure 1 is Figure 2 is a side view of the corresponding structure (and only one row of first protrusions 12 and one row of second protrusions 13 are shown), as shown in the figure, the plurality of first protrusions 12 are arranged at intervals to form a plurality of first hexagons 100, and the plurality of second protrusions 13 are arranged at intervals to form a plurality of second hexagons 200, each of the second hexagons 200 is located within one of the first hexagons 100. Figure 2

[0049] The first protrusions 12 and the second protrusions 13 are both conical, the height of the first protrusions 12 is greater than the height of the second protrusions 13, and the diameter of the bottom surface of the first protrusions 12 is greater than the diameter of the bottom surface of the second protrusions 13.

[0050] In the embodiment of the present disclosure, by arranging a plurality of first protrusions in a first hexagonal arrangement on the surface of the substrate body, the arrangement of the first protrusions reduces the proportion of the natural growth surface of the substrate, thereby reducing the epitaxial growth defects and further improving the epitaxial luminous brightness. Further, a second hexagon is arranged inside the first hexagon, the protrusion at the vertex of the second hexagon is smaller, occupying the part of the surface of the substrate body not occupied by the first protrusion, further reducing the proportion of the natural growth surface of the substrate and improving the epitaxial luminous brightness.

[0051] At the same time, the first protrusions and the second protrusions are both conical structures and are arranged at intervals, and the first protrusions and the second protrusions can further increase the light reflection rate of the patterned substrate, improve the luminous brightness of the light emitting diode chip, and ultimately improve the light emitting efficiency of the LED.

[0052] ​​Through comparative experiments, it is found that the luminous efficiency of the LED is significantly improved when the first protrusion 12 and the second protrusion 13 are simultaneously provided in the embodiment of the present disclosure, compared with only providing the first protrusion 12 .

[0053] See also Figure 2 In the embodiment of the present disclosure, two adjacent first hexagons 100 among the plurality of first hexagons 100 share two vertices, and the overlapping portion of the two adjacent first hexagons 100 is a parallelogram.

[0054] Two adjacent second hexagons 200 in the plurality of second hexagons 200 share a side.

[0055] Under this arrangement, the vertices of the first hexagon 100, that is, the first protrusions 12, are arranged at a high density, which lays the foundation for improving the luminous efficiency; on this basis, the vertices of the second hexagon 200, that is, the second protrusions 13 can be evenly arranged in the gaps between the first protrusions 12, thereby further improving the luminous efficiency.

[0056] In other embodiments, other arrangements may be used, for example, two adjacent first hexagons 100 share a side, and two adjacent second hexagons 200 are partially overlapped. Alternatively, two adjacent first hexagons 100 share a vertex, and two adjacent second hexagons 200 are independent of each other.

[0057] like Figure 2 As shown, a vertex of one of the two adjacent first hexagons 100 is located at the center of the other first hexagon 100 .

[0058] In this case, the six vertices of the second hexagon 200 are equidistant from the center of the first hexagon 100 .

[0059] In this implementation, the six vertices of the second hexagon 200 are equidistant from the center of the first hexagon 100, that is, the six second protrusions 13 are evenly distributed around the center of the first hexagon 100, thereby improving the luminous uniformity of the epitaxial growth on the substrate.

[0060] In the embodiment of the present disclosure, the second hexagon 200 may be a regular hexagon.

[0061] In the first hexagon 100 , a triangle formed by any side and the first protrusion 12 located at the center of the first hexagon 100 is an equilateral triangle. The center of any equilateral triangle is a second protrusion 13 .

[0062] When the above shape design is adopted, the distance between any vertex of the second hexagon 200 and the center of the first hexagon 100 is equal to the distance between any vertex of the second hexagon 200 and the nearest side of the first hexagon 100.

[0063] In this implementation, the six second protrusions 13 are evenly distributed in the gap of the first hexagon 100, further improving the uniformity of the epitaxial light emission grown on the substrate.

[0064] In other embodiments, the above first hexagon 100 and second hexagon 200 can also be other shapes of hexagons, for example, the first hexagon 100 is a regular hexagon, etc.

[0065] In the embodiments of the present disclosure, the first protrusion 12 and the second protrusion 13 can be straight circular cones. On the one hand, the straight circular cone is in contact with the epitaxial layer more uniformly, which is beneficial to defect improvement. On the other hand, the straight circular cone reflects light in various directions more uniformly, which is beneficial to light efficiency improvement.

[0066] In other embodiments, the first protrusion 12 and the second protrusion 13 can also be oblique circular cones.

[0067] In the embodiments of the present disclosure, the height of the first protrusion 12 is 1.7-2.0 μm, and the bottom diameter of the first protrusion 12 is 2.7-2.9 μm.

[0068] For example, the height of the first protrusion 12 is 1.8 μm, and the bottom diameter of the first protrusion 12 is 2.8 μm.

[0069] In the embodiments of the present disclosure, the height of the second protrusion 13 is 0.5-0.8 μm, and the bottom diameter of the second protrusion 13 is 0.5-0.8 μm.

[0070] For example, the height of the second protrusion 13 is 0.6 μm, and the bottom diameter of the second protrusion 13 is 0.6 μm.

[0071] In the embodiments of the present disclosure, the distance between adjacent first protrusions 12 is 0.14-0.16 μm, and the distance between adjacent second protrusions 13 is 0.09-0.11 μm.

[0072] For example, the distance between adjacent first protrusions 12 is 0.15 μm, and the distance between adjacent second protrusions 13 is 0.1 μm.

[0073] In the implementation, the size of the first protrusion 12 meets the epitaxial layer growth requirement and is limited by the thickness of the epitaxial layer, and the height and the bottom diameter can ensure the epitaxial growth quality and improve the light emitting efficiency. The size of the second protrusion 13 is limited by the gap between the first protrusions 12, and the height and the bottom diameter can maximize the light efficiency when the gap between the first protrusions 12 is 0.1-0.2 μm.

[0074] In the embodiment of the present disclosure, the thickness of the substrate body 11 is 600-700 μm.

[0075] For example, the thickness of the substrate body 11 is 650 μm.

[0076] Optionally, the material of the patterned substrate 10 can be one of sapphire, silicon, gallium nitride, silicon nitride, silicon carbide, and glass.

[0077] For example, the material of the patterned substrate 10 is sapphire, and the C face of the sapphire accounts for a small proportion after the first protrusion and the second protrusion are arranged, which can improve the epitaxial growth dislocation, improve the epitaxial crystal quality, and thus improve the light emitting efficiency.

[0078] Figure 3 is a structural schematic diagram of a light emitting diode provided by the embodiment of the present disclosure, as shown in Figure 3 The light emitting diode includes the patterned substrate 10 and the epitaxial structure 20 on the patterned substrate, as described in the above embodiment.

[0079] In the embodiment of the present disclosure, the epitaxial structure 20 includes a first semiconductor layer 21, an active layer 22, and a second semiconductor layer 23 which are sequentially stacked on the patterned substrate 10.

[0080] In the embodiment of the present disclosure, the material of the first semiconductor layer 21 can be N-type doped (such as silicon) gallium nitride (GaN).

[0081] For example, the thickness of the first semiconductor layer 21 can be 1 μm-1.5 μm, for example, 1 μm; the doping concentration of the N-type dopant in the first semiconductor layer 21 can be 10 18 / cm 3 -10 19 / cm 3 , for example, 5*10 18 / cm 3 .

[0082] In the embodiment of the present disclosure, the active layer 22 can include a plurality of quantum wells and a plurality of quantum barriers which are alternately stacked. The material of the quantum well can be indium gallium nitride (InGaN), and the material of the quantum barrier can be gallium nitride.

[0083] Exemplarily, the thickness of the active layer 22 can be 1500-2500 angstroms, for example, 2000 angstroms.

[0084] In the embodiments of the present disclosure, the material of the second semiconductor layer 23 can be P-type doped (such as magnesium) gallium nitride.

[0085] Exemplarily, the thickness of the second semiconductor layer 23 can be 300-500 angstroms, for example, 400 angstroms; the doping concentration of the P-type dopant in the second semiconductor layer 23 can be 10 18 / cm 3 ~10 20 / cm 3 , for example, 10 19 / cm 3 .

[0086] Optionally, the light-emitting diode can further include a physical vapor deposition (PVD) layer 24, a buffer layer 25 and an undoped layer 26, which are sequentially stacked between the patterned substrate 10 and the first semiconductor layer 21.

[0087] Exemplarily, the PVD layer 24 can be an aluminum nitride layer, and the thickness can be 150-250 angstroms, for example, 200 angstroms.

[0088] Exemplarily, the buffer layer 24 can be an aluminum nitride or aluminum gallium nitride layer, and the thickness can be 150-250 angstroms, for example, 200 angstroms.

[0089] Exemplarily, the undoped layer 26 can be an undoped GaN layer, and the thickness can be 3-5 microns, for example, 4 microns.

[0090] Optionally, the patterned substrate 10 without the convex side can further be provided with a reflective layer to ensure the light emission of the light-emitting diode.

[0091] Optionally, the light-emitting diode can further include a passivation layer, an electrode structure and the like, which will not be described herein.

[0092] Figure 4 is a preparation method flowchart of a patterned substrate provided by the embodiments of the present disclosure, as shown in the figure, the preparation method includes: Figure 4

[0093] Step 301, providing a substrate.

[0094] Optionally, the material of the substrate can be one of sapphire, silicon, gallium nitride, silicon nitride, silicon carbide and glass.

[0095] Exemplarily, the material of the substrate is sapphire.

[0096] ​Exemplarily, step 301 may include:

[0097] The substrate is placed in a MOCVD (Metal Organic Chemical Vapor Deposition) system and annealed in a N2 atmosphere for 10-15 minutes to clean the substrate surface at a temperature between 1000°C and 1200°C. The substrate is then nitrided.

[0098] Step 302: forming a mask layer on the substrate.

[0099] Exemplarily, step 302 may include:

[0100] The first step is to make a photoresist plate, and design a chrome light-shielding pattern on the surface of the photoresist plate. The chrome light-shielding pattern is the same as a pattern formed by the bottom surfaces of the plurality of first protrusions and the bottom surfaces of the plurality of second protrusions.

[0101] In the second step, photoresist is coated on the substrate using a coating machine.

[0102] Exemplarily, the thickness of the photoresist is 1.5-2.5 μm, for example, 2 μm.

[0103] The third step is to use a photolithography machine to perform exposure processing and transfer the photoresist pattern to the photoresist that has been coated.

[0104] The fourth step is to use a developer to develop the photoresist to reveal the pattern on the photoresist and obtain a mask layer.

[0105] The development process is performed using a TMAH (tetramethylammonium hydroxide) developer.

[0106] Step 303 : performing patterning on the substrate formed with the mask layer to obtain the patterned substrate.

[0107] Exemplarily, step 303 may include:

[0108] The substrate covered with the mask layer is placed on an aluminum tray of an inductively coupled plasma etching (ICP) etcher for etching to obtain the patterned substrate.

[0109] Wherein, the structure of the patterned substrate is as follows Figure 1 、 Figure 2 As shown, no further details are given here.

[0110] In the disclosed embodiment, multiple first protrusions arranged in a first hexagonal pattern are provided on the surface of the substrate body. The first protrusions reduce the proportion of the substrate's natural growth surface, thereby reducing epitaxial growth defects and improving epitaxial luminescence brightness. Furthermore, a second hexagon is provided within the first hexagon. The protrusions at the vertices of the second hexagon are smaller and occupy the portion of the substrate body's surface not occupied by the first protrusions, further reducing the proportion of the substrate's natural growth surface and improving epitaxial luminescence brightness.

[0111] At the same time, the first protrusion and the second protrusion are both conical structures and are spaced apart. The first protrusion and the second protrusion can further increase the reflected light output rate of the patterned substrate, improve the luminous brightness of the light-emitting diode chip, and ultimately improve the luminous efficiency of the LED.

[0112] Figure 5 This is a flow chart of a method for preparing a light-emitting diode provided by an embodiment of the present disclosure, such as Figure 5 As shown, the preparation method comprises:

[0113] Step 401: Provide a patterned substrate.

[0114] For example, the method for preparing a patterned substrate provided in the above embodiment can be used to prepare the following Figure 1 The patterned substrate shown in FIG. 3 is prepared in detail in FIG. Figure 3 , the embodiments of the present disclosure will not be described in detail here.

[0115] Step 402: sequentially grow a PVD layer, a buffer layer, and a non-doped layer on a patterned substrate.

[0116] For example, the PVD layer may be an aluminum nitride layer, and the thickness may be 150 to 250 angstroms, for example, 200 angstroms.

[0117] For example, the buffer layer may be an aluminum nitride layer or an aluminum gallium nitride layer, and may have a thickness of 150 to 250 angstroms, for example, 200 angstroms.

[0118] For example, the undoped layer may be an undoped GaN layer, and the thickness may be 3-5 μm, for example, 4 μm.

[0119] Step 403: growing a first semiconductor layer on the undoped layer.

[0120] Optionally, the material of the first semiconductor layer may be N-type doped (such as silicon) gallium nitride (GaN).

[0121] For example, the thickness of the first semiconductor layer may be 1 μm to 1.5 μm, for example, 1 μm; the doping concentration of the N-type dopant in the first semiconductor layer may be 10 18 / cm 3 ~1019 / cm 3 , for example 5*10 18 / cm 3 .

[0122] Exemplarily, step 403 can include:

[0123] The temperature of the reaction chamber is controlled at 1100-1150°C, and the pressure is controlled at 200 torr, to grow a first semiconductor layer with a thickness of 1-5 μm.

[0124] Step 404, growing an active layer on the first semiconductor layer.

[0125] Optionally, the active layer can include a plurality of quantum wells and a plurality of quantum barriers, which are alternately stacked. The material of the quantum well can be indium gallium nitride (InGaN), and the material of the quantum barrier can be gallium nitride.

[0126] Exemplarily, the thickness of the active layer can be 1500-2500 angstroms, for example 2000 angstroms.

[0127] Exemplarily, step 404 can include:

[0128] The temperature of the reaction chamber is controlled at 700-800°C, and the pressure is controlled at 100-200 torr, to grow a quantum well layer.

[0129] The temperature of the reaction chamber is controlled at 850-900°C, and the pressure is controlled at 100-200 torr, to grow a quantum barrier layer.

[0130] Step 405, growing a second semiconductor layer on the active layer.

[0131] Optionally, the material of the second semiconductor layer can be P-type doped (such as magnesium) gallium nitride.

[0132] Exemplarily, the thickness of the second semiconductor layer can be 300-500 angstroms, for example 400 angstroms; and the doping concentration of the P-type dopant in the second semiconductor layer can be 10 18 / cm 3 -10 20 / cm 3 , for example 10 19 / cm 3 .

[0133] Exemplarily, step 405 can include:

[0134] The temperature of the reaction chamber is controlled at 950-1000°C, and the pressure is controlled at 200 torr, to grow a second semiconductor layer with a thickness of 300-500 angstroms.

[0135] After the above steps are completed, the temperature of the reaction chamber is reduced to 650-850 DEG C, annealing treatment is carried out for 5-15 min in a nitrogen atmosphere, and then gradually reduced to room temperature, the epitaxial growth of the light emitting diode is ended, and the light emitting diode as shown in Figure 3 is obtained.

[0136] Optionally, the method can further include the fabrication of a passivation layer, an electrode structure, etc., which will not be described herein.

[0137] In the embodiments of the present disclosure, the patterned sapphire substrate (PSS) technology reduces the proportion of C-face sapphire by processing patterns on the sapphire surface, thereby reducing the dislocation of epitaxial growth. The embodiments of the present disclosure increase small patterns between adjacent large protrusions, further reducing the proportion of C-face. By controlling the height ratio of large and small patterns, the reflectivity can be increased to improve the brightness.

[0138] The above is only a preferred embodiment of the present disclosure, and is not intended to limit the present disclosure. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present disclosure shall be included in the protection scope of the present disclosure.

Claims

1. A patterned substrate, characterized in that The patterned substrate (10) comprises a substrate body (11), a plurality of first protrusions (12) and a plurality of second protrusions (13) located on the surface of the substrate body (11), the plurality of first protrusions (12) being arranged at intervals to form a plurality of first hexagons (100), the plurality of second protrusions (13) being arranged at intervals to form a plurality of second hexagons (200), and each of the second hexagons (200) being located within one of the first hexagons (100); The first protrusion (12) and the second protrusion (13) are both conical, the height of the first protrusion (12) is greater than the height of the second protrusion (13), and the bottom diameter of the first protrusion (12) is greater than the bottom diameter of the second protrusion (13).

2. The patterned substrate according to claim 1, wherein Two adjacent first hexagons (100) among the plurality of first hexagons (100) share two vertices, and an overlapping portion of the two adjacent first hexagons (100) is a parallelogram; Two adjacent second hexagons (200) among the plurality of second hexagons (200) share a common side.

3. The patterned substrate according to claim 2, wherein The six vertices of the second hexagon (200) are equidistant from the center of the first hexagon (100).

4. The patterned substrate according to claim 3, wherein The distance between any vertex of the second hexagon (200) and the center of the first hexagon (100) is equal to the distance between any vertex of the second hexagon (200) and the nearest side of the first hexagon (100).

5. The patterned substrate according to any one of claims 1 to 3, characterized in that: The height of the first protrusion (12) is 1.7 to 2.0 μm, and the bottom diameter of the first protrusion (12) is 2.7 to 2.9 μm.

6. The patterned substrate according to any one of claims 1 to 3, characterized in that: The height of the second protrusion (13) is 0.5 to 0.8 μm, and the bottom diameter of the second protrusion (13) is 0.5 to 0.8 μm.

7. The patterned substrate according to any one of claims 1 to 3, characterized in that: The thickness of the substrate body (11) is 600-700 μm.

8. A light emitting diode, characterized in that: The light emitting diode comprises a patterned substrate (10) according to any one of claims 1 to 7 and an epitaxial structure (20) located on the patterned substrate (10).

9. A method for preparing a patterned substrate, characterized in that: The preparation method comprises: providing a substrate; forming a mask layer on the substrate; The substrate with the mask layer formed thereon is patterned to obtain the patterned substrate, wherein the patterned substrate includes a substrate body, a plurality of first protrusions and a plurality of second protrusions on the surface of the substrate body, the plurality of first protrusions are arranged at intervals to form a plurality of first hexagons, the plurality of second protrusions are arranged at intervals to form a plurality of second hexagons, and each second hexagon is located within one of the first hexagons; the first protrusion and the second protrusion are both conical in shape, the height of the first protrusion is greater than the height of the second protrusion, and the bottom diameter of the first protrusion is greater than the bottom diameter of the second protrusion.

10. A method for preparing a light emitting diode, characterized in that: The preparation method comprises: A patterned substrate is obtained by the preparation method according to claim 9; An epitaxial structure is grown on the patterned substrate.

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