Multi-layer composite patterned substrate and preparation method and application thereof

Abstract

The invention discloses a multilayer composite patterned substrate and a preparation method and application thereof, and relates to the technical field of substrate material preparation. The invention provides a multi-layer composite patterned substrate which comprises a sapphire bottom layer, a periodic pattern layer and a reflecting material layer. The periodic pattern layer is arranged on the surface of the sapphire bottom layer; the periodic pattern layer is provided with a window area, and the window area is a non-coverage area of the periodic pattern layer on the sapphire bottom layer; a reflecting material layer is arranged on the surface of a non-window area of the periodic pattern layer; and an epitaxial layer can be additionally arranged between the sapphire bottom layer and the periodic pattern layer. According to the invention, the surface emergent light of the LED device is obviously increased, so that the external quantum efficiency is improved, and meanwhile, the problem that the GaN growth is influenced by a reflecting layer material (mainly a metal reflecting mirror material) is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of substrate material preparation, and in particular to a multi-layer composite patterned substrate and a preparation method and application thereof. Background Art

[0002] With the continuous advancement of GaN epitaxial technology and its widespread application, GaN-based LEDs have the advantage of being able to emit blue light sources and combined with phosphor technology to achieve the preparation of white light sources, making GaN-based LEDs almost universally used as core light sources in the current lighting and display fields. This breakthrough has promoted the rapid rise and widespread development of the GaN-LED industry.

[0003] In the field of GaN-LED technology, luminous efficiency has always been a core metric of concern for the industry. As a key parameter for measuring LED performance, luminous efficiency not only directly affects product price but also plays a crucial role in determining its market competitiveness. Pursuing higher luminous efficiency has always been the primary goal of GaN-LED technology development. Since the advent of LEDs, the design of substrate materials and their structures has played a crucial role in optimizing GaN-LED performance. To date, LED substrate technology has undergone three major generations of innovation:

[0004] First generation: Flat sapphire substrates. Initially, GaN single crystals were grown on flat sapphire substrates without any graphic or material modifications, and blue LEDs were successfully illuminated. However, the luminous efficiency of LEDs on these substrates was relatively low, making it difficult to meet the growing demand for applications.

[0005] Second Generation: Patterned Sapphire Substrate (PSS). Around 2008, researchers developed a new substrate—patterned sapphire substrate (PSS). By etching a periodic conical pattern on the sapphire surface, PSS significantly improved light extraction efficiency and crystal quality, significantly increasing LED brightness and driving technological advances in LED luminous efficiency. This innovation laid the foundation for the rapid development of the GaN-LED industry. After the second generation of LED substrates, the external quantum efficiency of LED devices grown on PSS substrates reached a bottleneck, making it difficult for the industry to achieve even a 0.5% brightness increase.

[0006] Third Generation: Composite Patterned Sapphire Substrate. In 2011, the inventors proposed a more advanced substrate technology—Compound Patterned Sapphire Substrate (CPSS). This substrate uses sapphire as the base material, and utilizes SiO2 material to create a specific patterned structure on its surface. After continuous technical optimization, this substrate has been gradually put into industrial application since 2019, further improving LED luminous efficiency by 2%-4%. This achievement not only marks another leap forward in LED technology, but also has attracted widespread attention and innovation in the industry.

[0007] Furthermore, in the field of LED devices, a common method for improving light extraction efficiency is to evaporate a reflective layer on the back of the sapphire substrate to enhance the overall light extraction efficiency of the device. However, the industry currently generally does not introduce a reflective layer between the front of the sapphire substrate and the GaN layer. The main reason is that the growth of GaN single crystals depends on the crystal phase guidance provided by the sapphire single crystal substrate to achieve high-quality GaN single crystal epitaxy. If a metal layer is covered on the sapphire surface, the crystal phase guidance function of the sapphire on the growth of GaN crystals will be isolated, resulting in the inability to complete the normal growth of GaN single crystals. Although a small number of literature reports on the growth of GaN after covering silicon substrates with metal, experimental results show that the quality of GaN crystals grown under such conditions is extremely poor, usually showing a blocky growth mode, and cannot form an ideal single crystal structure. Therefore, the internal quantum efficiency of LED devices based on such low-quality GaN materials will inevitably be severely affected, making it difficult to meet the requirements of high-performance LED devices. In addition, although placing a reflective layer on the back of the sapphire substrate can improve the light extraction efficiency to a certain extent, since most of the light will be reflected multiple times inside the sapphire substrate and eventually absorbed, the effect of this method is far inferior to the performance that can be achieved when the reflective layer is placed on the sapphire surface.

[0008] Based on the above technical background, it is urgent to explore more advanced substrate designs and technical means to achieve further breakthroughs in LED lighting efficiency. Summary of the Invention

[0009] The purpose of the present invention is to provide a multi-layer composite patterned substrate and a preparation method and application thereof, so as to solve the problems existing in the above-mentioned prior art.

[0010] To achieve the above object, the present invention provides the following solutions:

[0011] The present invention provides a multi-layer composite patterned substrate, comprising: a sapphire bottom layer, a periodic pattern layer and a reflective material layer;

[0012] The periodic pattern layer is arranged on the surface of the sapphire bottom layer;

[0013] The periodic pattern layer is provided with a window area, and the window area is an area where the periodic pattern layer does not cover the sapphire bottom layer;

[0014] The reflective material layer is provided on the surface of the non-window area of the periodic pattern layer.

[0015] Furthermore, the periodic pattern layer is composed of a sapphire layer and a heterogeneous material layer; the thickness ratio of the sapphire layer to the heterogeneous material layer is (0-0.95):(0.05-1);

[0016] When the thickness ratio of the sapphire layer to the heterogeneous material layer is not 0, the sapphire layer is in contact with the surface of the sapphire bottom layer;

[0017] The heterogeneous material layer is made of a material different from sapphire and GaN.

[0018] The structural diagram of the multi-layer composite patterned substrate (protruding periodic pattern layer) of the present invention is as follows: Figure 1 As shown, (a) is that the thickness ratio of the sapphire layer to the heterogeneous material layer is 0; (b) is that the thickness ratio of the sapphire layer to the heterogeneous material layer is not 0.

[0019] The structural diagram of the multi-layer composite patterned substrate (concave periodic pattern layer) of the present invention is as follows: Figure 2 As shown, (a) is that the thickness ratio of the sapphire layer to the heterogeneous material layer is 0; (b) is that the thickness ratio of the sapphire layer to the heterogeneous material layer is not 0.

[0020] The present invention also provides another multi-layer composite patterned substrate, comprising:

[0021] Sapphire bottom layer, epitaxial layer, periodic pattern layer and reflective material layer;

[0022] The epitaxial layer is arranged on the surface of the sapphire bottom layer, and the epitaxial layer is GaN or AlN;

[0023] The periodic pattern layer is arranged on the surface of the epitaxial layer;

[0024] The periodic pattern layer is provided with a window area, and the window area is a non-covering area of the epitaxial layer by the periodic pattern layer;

[0025] The reflective material layer is provided on the surface of the non-window area of the periodic pattern layer.

[0026] Furthermore, the thickness of the epitaxial layer is 0.1-0.5 μm.

[0027] Furthermore, the epitaxial layer is obtained by epitaxial growth on the sapphire bottom layer using MOCVD or PVD technology.

[0028] In the above-mentioned two structures of the multi-layer composite patterned substrate of the present invention, the reflective material layer includes Pd, Pt, Ag, Al, Au and various high reflectivity materials or synthetic substances.

[0029] In the multi-layer composite patterned substrate of the above two structures of the present invention, the reflective material layer also includes an adhesive material; the adhesive material can be a metal that increases adhesion (including metals such as Ti and Ni), and its main function is to enhance the adhesion between the reflective material of the reflective material layer and the substrate to avoid the reflective material layer from falling off during the back-end process. The material needs to not decompose at high temperatures above 800°C.

[0030] In the multi-layer composite patterned substrate of the above two structures of the present invention, the heterogeneous material layer is SiO2, Si3N4, SiC, Si, ZnO or GaAs.

[0031] In the above-mentioned two structures of the multi-layer composite patterned substrate of the present invention, the thickness of the reflective material layer is preferably 0.1 nm-2 μm, more preferably 1 nm-1 μm.

[0032] The multi-layer composite patterned substrate of the above two structures of the present invention, the periodic pattern layer can be the following patterns: raised cone, cylinder, trapezoidal truncated cone, triangular cone, square cone, square column, triangular square cone, trapezoidal square cone, pentagonal cone, pentagonal column, trapezoid, pentagonal cone, hexagonal cone, hexagonal column, trapezoidal hexagonal cone, 12-sided cone, 12-sided column, trapezoidal 12-sided cone and other polygonal cones, polygonal columns and trapezoidal polygonal cones.

[0033] The multi-layer composite patterned substrate of the above two structures of the present invention, the periodic pattern layer can also be the following patterns: concave conical pits, cylindrical pits, trapezoidal truncated cone pits, triangular conical pits, triangular cone pits, square conical pits, square columnar pits, trapezoidal square cone pits, pentagonal conical pits, pentagonal columnar pits, trapezoidal pentagonal cone pits, hexagonal conical pits, hexagonal columnar pits, trapezoidal hexagonal cone pits, 12-sided conical pits, 12-sided columnar pits, trapezoidal 12-sided cone pits and other polygonal conical pits, polygonal columnar pits and trapezoidal polygonal cone pits.

[0034] The schematic diagram of the raised periodic graphic layer of the present invention is as follows Figure 3 As shown; the schematic diagram of the concave periodic graphic layer is as follows Figure 4 shown.

[0035] Furthermore, the period of the periodic pattern (the distance between the central axes of the two patterns, represented by the letter A) is preferably 0.2-50 microns, more preferably 1-10 microns; the bottom diameter of the periodic pattern (represented by the letter W) is 0.1-50 microns, more preferably 0.8-9 microns; the height of the periodic pattern (represented by the letter d) is preferably 0.1-3 microns, more preferably 0.5-2.3 microns.

[0036] Furthermore, the heterogeneous material layer of the present invention has the following characteristics:

[0037] (1) It has the characteristics of high temperature resistance and does not decompose at high temperatures above 800℃;

[0038] (2) can exist in the form of single crystal material;

[0039] (3) The refractive index is significantly different from that of GaN.

[0040] Furthermore, the heterogeneous material can form a thin film on the sapphire substrate by growth, sputtering or deposition.

[0041] The present invention further provides the use of the two multi-layer composite patterned substrates in growing GaN-based LED devices.

[0042] Furthermore, GaN is epitaxially grown on the side of the two multi-layer composite patterned substrates having the reflective material layer.

[0043] In the field of LED devices, luminous efficiency has always been the core indicator for measuring their performance. Every improvement in luminous efficiency has the potential to trigger profound changes in the industry. The quantum well region is a key component in achieving electro-optical conversion. The performance of the quantum well directly determines the device's photoelectric conversion efficiency, a parameter known as the internal quantum efficiency (IQE). From the perspective of the entire device, the device's actual light output efficiency, that is, the ratio of the light power emitted outside the device to the injected electrical power, is defined as the external quantum efficiency (EQE). After years of development, the internal quantum efficiency of LED devices has reached over 90%, meaning that the vast majority of injected carriers can be successfully converted into photons in the quantum well. However, while the internal quantum efficiency is close to the theoretical limit, the external quantum efficiency remains relatively low, from less than 10% in the early days to only around 50% today.

[0044] The main reason for the limited external quantum efficiency is that the photons generated by the quantum well undergo multiple refractions and total reflections within the GaN material and sapphire substrate. Ultimately, most photons fail to escape the device and are instead reabsorbed by the material, significantly reducing the light extraction efficiency of the entire device. Therefore, improving light extraction efficiency and reducing photon losses within the material have become key technical challenges for further improving the external quantum efficiency of LEDs.

[0045] To improve the reflective performance of LED devices, the first consideration is to evaporate a layer of reflective layer material onto the entire surface of the sapphire substrate to enhance the surface light extraction efficiency. However, this method has a significant technical bottleneck: since the commonly used reflective layer materials are mostly metal, their coverage will hinder the normal growth of the GaN epitaxial layer. The growth of GaN single crystals depends on the crystal phase guidance provided by the lattice surface of the sapphire substrate. The introduction of a metal reflective layer will isolate this effect, resulting in the inability to achieve high-quality epitaxial growth of GaN crystals.

[0046] The present invention places the reflective layer material only on the surface of the heterogeneous material layer, while retaining the exposed sapphire surface in the window area. Through this design, GaN crystals can begin to grow from the sapphire surface in the window area, and with the help of lateral epitaxy technology, the crystals are closed to complete the high-quality single crystal growth process. This method not only ensures that the crystal quality of the GaN epitaxial layer is not affected, but also fully utilizes the optical properties of the reflective layer on the surface of the heterogeneous material pattern, significantly improving the external quantum efficiency (EQE) of the LED device, thereby achieving the ideal performance optimization goal.

[0047] Through ingenious design, this invention successfully places a metal reflective layer on the surface of a sapphire substrate while ensuring it does not interfere with the normal growth of GaN single crystals. This technological breakthrough not only solves the problem of photon absorption by the sapphire substrate in traditional methods, but also significantly improves the overall light extraction efficiency of LED devices, bringing new possibilities to the industry.

[0048] The reflective layer material introduced in this invention significantly enhances the light reflection performance at the interface between the GaN layer and the sapphire substrate. This improvement effectively increases the amount of light emitted from the LED device surface, thereby significantly improving the external quantum efficiency (EQE). At the same time, the design of this reflective layer material cleverly eliminates the adverse effects that traditional metal reflector materials may have on GaN crystal growth.

[0049] The reflective layer material of the present invention can enhance the light reflection on the surface between the GaN layer and the sapphire substrate, thereby significantly increasing the surface light output of the LED device, thereby improving the external quantum efficiency. At the same time, it also solves the problem that the reflective layer material (mainly metal reflector material) affects the growth of GaN.

[0050] The present invention discloses the following technical effects:

[0051] (1) To address the problem in traditional methods where the metal reflective layer covers the sapphire substrate, resulting in the inability of the GaN epitaxial layer to grow normally, the present invention effectively avoids the influence of the metal reflective layer on the growth of GaN crystals by setting the reflective layer material only on the surface of the heterogeneous material layer and retaining the exposed sapphire surface in the window area.

[0052] (2) The present invention preserves the sapphire surface in the window area, allowing the GaN crystal to grow from the window area, and uses lateral epitaxial growth technology to achieve crystal closure, ensuring a high-quality single crystal growth process, thereby significantly improving the crystal quality of the GaN epitaxial layer.

[0053] (3) The present invention introduces a reflective layer material (such as a metal reflector material) on the surface of the heterogeneous material layer, which significantly enhances the light reflection performance between the GaN layer and the sapphire substrate interface, and effectively increases the light output from the surface of the LED device.

[0054] (4) By optimizing the light reflection performance, the present invention significantly improves the external quantum efficiency (EQE) of LED devices, achieves the ideal performance optimization goal, solves the problem of photon absorption by the sapphire substrate, and takes into account the needs of GaN crystal growth and optical performance improvement, providing a new solution for the performance optimization of LED devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0056] Figure 1 Schematic diagram of the structure of a multi-layer composite patterned substrate (raised periodic pattern layer), where (a) contains a sapphire layer and (b) does not contain a sapphire layer;

[0057] Figure 2 Schematic diagram of the structure of a multi-layer composite patterned substrate (a) containing a sapphire layer and a substrate without a sapphire layer;

[0058] Figure 3 Schematic diagram of the raised periodic pattern layer of the present invention;

[0059] Figure 4 Schematic diagram of the concave periodic pattern layer of the present invention;

[0060] Figure 5 Actual pictures of the SCPSS and composite patterned sapphire substrate (CPSS) prepared in Example 1 of the present invention (the dark surface is the SCPSS, and the white surface is the CPSS). DETAILED DESCRIPTION

[0061] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0062] It should be understood that the terms described herein are intended only to describe particular embodiments and are not intended to limit the present invention. In addition, for numerical ranges herein, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. The intermediate value within any stated value or stated range, and each smaller range between any other stated value or intermediate value within the stated range, is also encompassed within the present invention. The upper and lower limits of these smaller ranges may be independently included or excluded within the scope.

[0063] Unless otherwise indicated, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art. Although only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein may also be used in the practice or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of any conflict with any incorporated document, the contents of this specification shall prevail.

[0064] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments described herein without departing from the scope or spirit of the invention. Other embodiments will be apparent to those skilled in the art from the description of the invention. The description and examples are intended to be illustrative only.

[0065] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0066] It should be pointed out that the matters not described in detail in the present invention are conventional operating means in this field and are not the focus of the present invention.

[0067] Example 1

[0068] A multi-layer composite patterned substrate, comprising a sapphire bottom layer, a periodic patterned layer, and a reflective material layer;

[0069] A periodic pattern layer is arranged on the surface of the sapphire bottom layer; the periodic pattern layer (including the SiO2 layer and the sapphire layer) is provided with a window area, which is the non-covering area of the periodic pattern layer on the sapphire bottom layer; a reflective material layer (Pd metal) is provided on the surface of the non-window area of the periodic pattern layer.

[0070] The preparation steps are as follows:

[0071] (1) A sapphire single crystal substrate with a thickness of 600 μm and a diameter of 4 inches was selected as the bottom layer;

[0072] (2) Using plasma enhanced chemical vapor deposition (PECVD) technology, a SiO2 film with a thickness of 2.0 μm is grown on the surface of the sapphire substrate.

[0073] (3) A 2.4 μm thick layer of photoresist is applied to the surface of the SiO2 film using a coating machine. Using photolithography technology, the photoresist is etched into a periodic cylindrical structure with a base diameter of 2 μm, a height of 2.4 μm, and a period of 3 μm.

[0074] (4) Using inductively coupled plasma (ICP) etching technology, the SiO2 film on the surface of the sapphire substrate is etched using the photoresist cylinder formed in step (3) as a mask. After etching, a conical pattern with a base diameter of 2.85 microns, a height of 2.0 microns, and a period of 3 microns is formed, thus obtaining a periodic pattern layer. The conical pattern is evenly distributed on the surface of the sapphire substrate, with the upper portion being composed of SiO2 and the lower portion being exposed to the sapphire substrate material, with the height ratio of the two being 0.95:0.05. The window area completely exposes the sapphire substrate.

[0075] (5) Using electron beam evaporation (E-Beam) technology, a layer of Pd metal with a thickness of 30 nm is evaporated on the surface of the periodic pattern layer as the basis for the subsequent reflective layer.

[0076] (6) A layer of photoresist with a thickness of 500 nm is again applied to the surface of the Pd-deposited substrate using a coating technique. The periodic cylindrical pattern from step (3) is precisely overlaid onto the photoresist surface using photolithography, resulting in a state where the pattern area is covered with photoresist and the window area is free of photoresist.

[0077] (7) Using ICP etching technology, the Pd metal in the window area is selectively etched away to expose the sapphire substrate surface while retaining the Pd metal in the graphic area.

[0078] (8) All residual photoresist is completely removed through a cleaning process, completing the entire preparation process and obtaining a multilayer structure composite patterned substrate (labeled as SCPSS).

[0079] Example 2

[0080] (1) A sapphire single crystal substrate with a thickness of 680 μm and a diameter of 4 inches was selected as the bottom layer;

[0081] (2) Using plasma enhanced chemical vapor deposition (PECVD) technology, a SiO2 film with a thickness of 2.0 μm is grown on the surface of the sapphire substrate.

[0082] (3) A 2.4 μm thick layer of photoresist is applied to the surface of the SiO2 film using a coating machine. Using photolithography technology, the photoresist is etched into a periodic cylindrical structure with a base diameter of 2 μm, a height of 2.4 μm, and a period of 3 μm.

[0083] (4) Using inductively coupled plasma (ICP) etching technology, the SiO2 film on the surface of the sapphire substrate is etched using the photoresist cylinder formed in step (3) as a mask. After etching, a conical pattern with a base diameter of 2.9 microns, a height of 1.8 microns, and a period of 3 microns is formed, thus obtaining a periodic pattern layer. These conical patterns are evenly distributed on the surface of the sapphire substrate, with the upper portion being composed of SiO2 and the lower portion exposing the sapphire substrate material, and the height ratio of the two is 0.95:0.05. The window area completely exposes the sapphire substrate.

[0084] (6) Using E-Beam technology, a Ti / Pd metal layer (Ti layer thickness is 5 nm, Pd thickness is 30 nm) is evaporated on the surface of the substrate with the periodic pattern etched above;

[0085] (7) Using a coating technique, a 500 nm photoresist is coated on the surface of the substrate on which the Ti / Pd metal is evaporated. Using a photolithography technique, the pattern of step (4) is overlaid on the surface of the photoresist, forming a morphology in which the pattern surface is covered with photoresist and the window area is free of photoresist;

[0086] (8) Using ICP etching technology, the Ti / Pd metal in the window area of the above-mentioned photolithographic sample is etched away to expose the sapphire surface in the window area;

[0087] (9) The photoresist is cleaned and removed, and the product is prepared to obtain a multi-layer structure composite patterned substrate.

[0088] Example 3

[0089] The only difference from Example 1 is that in step (2), a Si3N-4 film with a thickness of 2.0 μm is grown on the surface of the sapphire substrate using plasma enhanced chemical vapor deposition (PECVD) technology.

[0090] Example 4

[0091] The only difference from Example 1 is that in step (4), the photoresist is formed into a square column with a side length of 2 μm, and a square pyramid pattern is obtained by etching.

[0092] Example 5

[0093] A multi-layer composite patterned substrate, comprising a sapphire bottom layer, an epitaxial layer, a periodic patterned layer, and a reflective material layer;

[0094] The epitaxial layer is arranged on the surface of the sapphire bottom layer; the periodic pattern layer (including the SiO2 layer and the sapphire layer) is provided with a window area, which is the non-covering area of the epitaxial layer by the periodic pattern layer; the non-window area surface of the periodic pattern layer is provided with a reflective material layer (Pd metal).

[0095] The preparation steps are the same as those in Example 1, except that a 3 μm thick GaN single crystal layer is grown on the sapphire surface by MOCVD before step (2).

[0096] Example 6

[0097] A multi-layer composite patterned substrate, comprising a sapphire bottom layer, an epitaxial layer, a periodic patterned layer, and a reflective material layer;

[0098] The epitaxial layer is arranged on the surface of the sapphire bottom layer; the periodic pattern layer (including the SiO2 layer and the sapphire layer) is provided with a window area, which is the non-covering area of the epitaxial layer by the periodic pattern layer; the non-window area surface of the periodic pattern layer is provided with a reflective material layer (Pd metal).

[0099] The preparation steps are the same as those in Example 1, except that a 3 μm thick AlN single crystal layer is grown on the sapphire surface by MOCVD before step (2).

[0100] Figure 5 Actual pictures of the SCPSS and composite patterned sapphire substrate (CPSS) prepared in Example 1 (the dark surface is SCPSS, and the white surface is CPSS).

[0101] The performance comparison of the SCPSS prepared in Example 1 and the CPSS prepared in Comparative Example 1 is shown in Table 1:

[0102] Table 1

[0103]

[0104]

[0105] The embodiments described above are merely descriptions of preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by persons skilled in the art should fall within the scope of protection defined by the claims of the present invention.

Claims

1. A multi-layer composite patterned substrate, characterized in that: include: Sapphire bottom layer, periodic pattern layer and reflective material layer; The periodic pattern layer is arranged on the surface of the sapphire bottom layer; The periodic pattern layer is provided with a window area, and the window area is an area where the periodic pattern layer does not cover the sapphire bottom layer; The reflective material layer is provided on the surface of the non-window area of the periodic pattern layer.

2. The multi-layer composite patterned substrate according to claim 1, characterized in that: The periodic pattern layer is composed of a sapphire layer and a heterogeneous material layer; the thickness ratio of the sapphire layer to the heterogeneous material layer is (0-0.95):(0.05-1); When the thickness ratio of the sapphire layer to the heterogeneous material layer is not 0, the sapphire layer is in contact with the surface of the sapphire bottom layer; The heterogeneous material layer is made of a material different from sapphire and GaN.

3. The multi-layer composite patterned substrate according to claim 2, characterized in that: The heterogeneous material layer is SiO2, Si3N4, SiC, Si, ZnO or GaAs.

4. A multi-layer composite patterned substrate, characterized in that: include: Sapphire bottom layer, epitaxial layer, periodic pattern layer and reflective material layer; The epitaxial layer is arranged on the surface of the sapphire bottom layer, and the material of the epitaxial layer is GaN or AlN; The periodic pattern layer is arranged on the surface of the epitaxial layer; The periodic pattern layer is provided with a window area, and the window area is a non-covering area of the epitaxial layer by the periodic pattern layer; The reflective material layer is provided on the surface of the non-window area of the periodic pattern layer.

5. The multi-layer composite patterned substrate according to claim 4, characterized in that: The thickness of the epitaxial layer is 0.1-0.5 μm.

6. The multi-layer composite patterned substrate according to claim 4, characterized in that: The periodic pattern layer is composed of a sapphire layer and a heterogeneous material layer; the thickness ratio of the sapphire layer to the heterogeneous material layer is (0-0.95):(0.05-1); When the thickness ratio of the sapphire layer to the heterogeneous material layer is not 0, the sapphire layer is in contact with the surface of the sapphire bottom layer; The heterogeneous material layer is made of a material different from sapphire and GaN.

7. The multi-layer composite patterned substrate according to claim 6, characterized in that: The heterogeneous material layer is SiO2, Si3N4, SiC, Si, ZnO or GaAs.

8. Use of the multilayer composite patterned substrate according to any one of claims 1 to 3 or the multilayer composite patterned substrate according to any one of claims 4 to 7 in growing a GaN-based LED device.

9. The use according to claim 8, characterized in that The multilayer composite patterned substrate according to any one of claims 1 to 3 or the multilayer composite patterned substrate according to any one of claims 4 to 7 has GaN epitaxially grown on one side of the reflective material layer.

Images