An LED chip based on an alumina-silica composite substrate and a manufacturing method thereof

Abstract

The present application provides an LED chip based on an alumina-silica composite substrate and a manufacturing method thereof. The LED chip includes an alumina-silica composite PSS substrate, a composite buffer layer, and an LED structure layer. Among them, the composite buffer layer is epitaxially grown on the alumina-silica composite PSS substrate, and the LED structure layer is epitaxially grown on the composite buffer layer. The composite buffer layer includes: an aluminum oxynitride / aluminum nitride layer and a silicon oxynitride layer. The aluminum on the alumina in the alumina-silica composite PSS substrate is covered by the aluminum oxynitride / aluminum nitride layer, and the silicon on the silica in the alumina-silica composite PSS substrate is covered by the alternating and spaced aluminum oxynitride / aluminum nitride layer and silicon oxynitride layer. The composite buffer layer has better thickness uniformity on the alumina and silica materials, and can better buffer the lattice mismatch and stress release caused by different materials between the alumina-silica composite PSS substrate and the LED epitaxial bottom layer, reducing defects at the interface layer.

Description

Technical Field

[0001] This application relates to the technical field of LED chips, and particularly relates to an LED chip based on an alumina-silica composite substrate and a manufacturing method thereof. Background Art

[0002] An LED (Light Emitting Diode) is a commonly used light-emitting device that emits light by the recombination of electrons and holes. LED products are widely used in various industries and play an important role in people's daily life and production. In the industry, the MOCVD (Metal-Organic Chemical Vapour Deposition) method is mainly used to prepare the epitaxial wafers of LEDs, and generally a PSS substrate (Patterned Sapphire Substrate) is used. A mask for dry etching is grown on the PSS substrate material, and the mask is patterned using a standard photolithography process. Then, the sapphire is etched using ICP (inductively coupled plasma) etching technology and the mask is removed, and a GaN (gallium nitride) material is grown thereon, so that the longitudinal epitaxy of the GaN material becomes lateral epitaxy. On the one hand, it can effectively reduce the dislocation density of the GaN epitaxial material, thereby reducing the non-radiative recombination in the active region, reducing the reverse leakage current, and improving the lifespan of the LED. On the other hand, the light emitted from the active region is scattered multiple times at the interface between GaN and the sapphire substrate, changing the exit angle of the total reflection light and increasing the probability of the light of the flip-chip LED exiting from the sapphire substrate, thereby improving the light extraction efficiency.

[0003] The LED market tends to be stable and conventional manufacturing, and the demand for high-end and sophisticated products is becoming increasingly urgent, especially for high luminous efficacy products. However, the difficulty of improving the internal quantum efficiency is increasing day by day, which makes the measures to improve the external quantum efficiency and the light extraction efficiency more important. In the industry, in order to improve the external quantum efficiency and the light extraction efficiency, generally, an alumina-silica (Al2O3 / SiO2) composite PSS substrate is used in combination with an LED stack crystal bottom layer, that is, an Al2O3 / SiO2 composite PSS substrate is used, and a layer of AlN (aluminum nitride) is epitaxially grown on the pattern of the Al2O3 / SiO2 composite PSS substrate as a buffer layer, and then an LED structure layer is epitaxially grown on the buffer layer.

[0004] However, on the one hand, due to the large difference in the growth rates of AlN and GaN materials on the Al2O3 material and the SiO2 material in the patterned part of the Al2O3 / SiO2 composite PSS substrate, the thickness uniformity of the AlN buffer layer is poor; on the other hand, in the SiO2 patterned part of the Al2O3 / SiO2 composite PSS substrate, the lattice quality of the SiO2 material layer is poor, and there are problems such as a high concentration of oxygen vacancy defects. Summary of the Invention

[0005] The present application provides an LED chip based on an alumina-silica composite substrate and a manufacturing method thereof to solve the problems of poor thickness uniformity of the AlN buffer layer and poor lattice quality.

[0006] In a first aspect, the present application provides an LED chip based on an alumina-silica composite substrate, including: an alumina-silica composite PSS substrate, a composite buffer layer, and an LED structure layer. Among them, the composite buffer layer is epitaxially grown on the alumina-silica composite PSS substrate, and the LED structure layer is epitaxially grown on the composite buffer layer; the composite buffer layer includes: an aluminum oxynitride / aluminum nitride layer and a silicon oxynitride layer. The aluminum oxynitride / aluminum nitride layer covers the alumina in the alumina-silica composite PSS substrate, and the aluminum oxynitride / aluminum nitride layer and the silicon oxynitride layer are alternately and intermittently covered on the silica in the alumina-silica composite PSS substrate; the aluminum oxynitride in the aluminum oxynitride / aluminum nitride layer is connected to the alumina-silica composite PSS substrate, and the aluminum nitride in the aluminum oxynitride / aluminum nitride layer is connected to the LED structure layer.

[0007] Optionally, the thickness of the aluminum oxynitride in the aluminum oxynitride / aluminum nitride layer is 30%-60% of the overall thickness of the aluminum oxynitride / aluminum nitride layer.

[0008] Optionally, the thickness of the aluminum oxynitride / aluminum nitride layer is 100-250 Å, and the thickness of the silicon oxynitride layer is 100-300 Å.

[0009] In a second aspect, the present application further provides a manufacturing method for an LED chip based on an alumina-silica composite substrate, which is used to manufacture an LED chip based on an alumina-silica composite substrate described in the first aspect. The manufacturing method includes: placing the alumina-silica composite PSS substrate in a physical vapor deposition device, and epitaxially growing an aluminum oxynitride / aluminum nitride layer by physical vapor deposition to obtain a first substrate; placing the first substrate in a metal organic chemical vapor deposition device, and epitaxially growing a silicon oxynitride layer by metal organic chemical vapor deposition to obtain a second substrate; and epitaxially growing an LED structure layer on the second substrate.

[0010] Optionally, the step of placing the alumina-silica composite PSS substrate into a physical vapor deposition device and epitaxially growing an aluminum oxynitride / aluminum nitride layer by physical vapor deposition to obtain a first substrate includes: in the chamber of the physical vapor deposition device, in a nitrogen atmosphere, bombarding an aluminum target with argon through magnetron sputtering on the surface of the alumina-silica composite PSS substrate substrate, introducing oxygen, and reacting to obtain an aluminum oxynitride thin film epitaxially growing on the alumina-silica composite PSS substrate; stopping introducing oxygen and reacting to obtain an aluminum nitride thin film epitaxially growing on the aluminum oxynitride layer to obtain a first substrate.

[0011] Optionally, the sputtering power of the physical vapor deposition device is set in the range of 3000 - 4500 W, and the sputtering temperature is set in the range of 500 - 650 °C; the flow rate of the introduced oxygen is 2 sccm - 6 sccm, and the time of introducing oxygen is 30% - 60% of the total time of physical vapor deposition epitaxial growth.

[0012] Optionally, the step of placing the first substrate into a metalorganic chemical vapor deposition device and epitaxially growing a silicon oxynitride layer by metalorganic chemical vapor deposition to obtain a second substrate includes: in the metalorganic chemical vapor deposition device, performing heat treatment on the first substrate in a hydrogen atmosphere at a first preset temperature for a first preset time; converting the atmosphere into a mixed atmosphere of nitrogen and ammonia, where nitrogen is the carrier gas and ammonia is the reaction gas to provide a nitrogen source, and performing a thermal displacement reaction at a second preset temperature, and reacting to obtain a silicon oxynitride layer epitaxially growing on the first substrate, the second preset temperature being less than the first preset temperature, and the thermal displacement reaction lasting for a second preset time; maintaining the mixed atmosphere of nitrogen and ammonia, and controlling the temperature to drop to a third preset temperature for annealing treatment, the third preset temperature being less than the second preset temperature, and the annealing treatment lasting for a third preset time to obtain a second substrate.

[0013] Optionally, the first preset temperature range is 1050 °C - 1150 °C, and the first preset time range is 1 - 5 min; the second preset temperature range is 800 °C - 1000 °C, and the second preset time range is 5 min - 20 min; the third preset temperature range is 550 °C - 650 °C, and the third preset time range is 20 min - 30 min.

[0014] Optionally, the thickness of the epitaxially grown aluminum oxynitride / aluminum nitride layer is 100 - 250 Å, and the thickness of the epitaxially grown silicon oxynitride layer is 100 - 300 Å.

[0015] The present application provides an LED chip based on an alumina-silica composite substrate and a manufacturing method thereof. The LED chip includes an alumina-silica composite PSS substrate, a composite buffer layer, and an LED structure layer. Among them, the composite buffer layer is epitaxially grown on the alumina-silica composite PSS substrate, and the LED structure layer is epitaxially grown on the composite buffer layer. The composite buffer layer includes: an aluminum oxynitride / aluminum nitride layer and a silicon oxynitride layer. The aluminum oxynitride / aluminum nitride layer covers the alumina in the alumina-silica composite PSS substrate, and the aluminum oxynitride / aluminum nitride layer and the silicon oxynitride layer are alternately and spacedly covered on the silica in the alumina-silica composite PSS substrate; the aluminum oxynitride in the aluminum oxynitride / aluminum nitride layer is connected to the alumina-silica composite PSS substrate, and the aluminum nitride in the aluminum oxynitride / aluminum nitride layer is connected to the LED structure layer. The composite buffer layer has better thickness uniformity on alumina and silica materials, and can better buffer the lattice mismatch and stress release caused by different materials between the alumina-silica composite PSS substrate and the LED epitaxial bottom layer, reducing defects at the interface layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, for those of ordinary skill in the art, other drawings can also be obtained based on these drawings without creative efforts.

[0017] Figure 1 Schematic diagram of the structure of an LED chip based on an alumina-silica composite substrate according to the present application;

[0018] Figure 2 Schematic diagram of the structure of the Al2O3 / SiO2 composite PSS substrate according to the present application;

[0019] Figure 3 Schematic diagram of the structure of an AlN buffer layer;

[0020] Figure 4 Schematic diagram of the structure of an LED chip with an AlN buffer layer;

[0021] Figure 5 TEM image one of an LED chip with an AlN buffer layer;

[0022] Figure 6 TEM image two of an LED chip with an AlN buffer layer;

[0023] Figure 7 TEM image one of an LED chip based on an alumina-silica composite substrate according to the present application;

[0024] Figure 8TEM image two of an LED chip based on an alumina-silica composite substrate according to the present application;

[0025] Figure 9 Process schematic diagram of a manufacturing method of an LED chip based on an alumina-silica composite substrate according to the present application;

[0026] Figure 10 MOCVD epitaxial growth of SiO on the first substrate according to the present application x N y Process schematic diagram of obtaining a second substrate;

[0027] Figure 11 Epitaxial growth of AlO on an Al2O3 / SiO2 composite PSS substrate according to the present application x N y Structure schematic diagram of the layer;

[0028] Figure 12 Epitaxial growth of an AlN layer on the AlO x N y Structure schematic diagram of the layer;

[0029] Figure 13 Structure schematic diagram of the AlO x N y / AlN layer after heat treatment;

[0030] Figure 14 Structure schematic diagram of the composite buffer layer according to the present application;

[0031] Figure 15 Is Figure 14 Magnified structure schematic diagram of the circled part in; Specific embodiments

[0032] The embodiments will be described in detail below, and the examples are shown in the drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following examples do not represent all embodiments consistent with the present application. They are merely examples of systems and methods consistent with some aspects of the present application as detailed in the claims.

[0033] Epitaxial growth refers to growing a single crystal layer with certain requirements and the same crystal orientation as the substrate on a single crystal substrate (wafer), as if the original crystal has extended outward for a certain section. There are various methods for growing epitaxial layers, such as: liquid phase epitaxy (PE), physical vapor deposition (PVD), metal organic chemical vapor deposition (MOCVD), hydride vapor phase epitaxy (HVPE), molecular beam epitaxy (MBE), etc. Generally, the MOCVD epitaxial process is most commonly used in industrial production.

[0034] Metal-organic Chemical Vapor Deposition (MOCVD) is a new type of vapor phase epitaxial growth technology developed on the basis of vapor phase epitaxial growth (VPE). MOCVD uses organic compounds of group III and group II elements, hydrides of group V and group VI elements, etc. as crystal growth source materials, and conducts vapor phase epitaxy on the substrate in a thermal decomposition reaction mode to grow thin single crystal materials of various group III-V main group, group II-VI subgroup compound semiconductors and their multiple solid solutions. MOCVD has the advantages of precise control of crystal growth, good repeatability, large output, and suitability for industrial mass production.

[0035] Physical Vapour Deposition (PVD) technology is a thin film technology with a special function deposited on the surface of a substrate under vacuum conditions by using physical methods to vaporize the material source (solid or liquid) into gaseous atoms, molecules or partially ionize them into ions, and through a low-pressure gas (or plasma) process.

[0036] In some embodiments, refer to Figure 2 an Al2O3 / SiO2 composite PSS substrate; an AlN (aluminum nitride) buffer layer is epitaxially grown on the Al2O3 / SiO2 composite PSS substrate pattern, as Figure 3 shown; then an LED structure layer is epitaxially grown on the AlN buffer layer, as Figure 4 shown.

[0037] However, on the one hand, due to the growth rates of AlN and GaN materials, there is a relatively large difference between the Al2O3 material and the SiO2 material in the Al2O3 / SiO2 composite PSS substrate pattern part; on the other hand, in the SiO2 pattern part of the Al2O3 / SiO2 composite PSS substrate, the lattice quality of the SiO2 material layer is poor, and there are problems such as a relatively high concentration of oxygen vacancy defects. Figure 5 and Figure 6 are the microscopic images obtained by using a Transmission Electron Microscope (TEM) in the above embodiments. As can be seen from Figure 6 the thickness of the AlN buffer layer on the SiO2 material in the Al2O3 / SiO2 composite PSS substrate pattern part is 49A and 74A, while the thickness of the AlN buffer layer on the Al2O3 material in the Al2O3 / SiO2 composite PSS substrate pattern part is 125A and 152A. It can be seen that the thickness difference between the two is nearly twice, and the thickness uniformity is not good. And from Figure 5The position of the arrow in [it] can clearly show problems such as oxygen vacancy defects in the SiO2 pattern part of the Al2O3 / SiO2 composite PSS substrate.

[0038] To solve the above problems, this application provides an LED chip based on an alumina-silica composite substrate, as Figure 1 shown, including: an alumina-silica (Al2O3 / SiO2) composite PSS substrate, a composite buffer layer, and an LED structure layer. Among them, the composite buffer layer is epitaxially grown on the alumina-silica composite PSS substrate, and the LED structure layer is epitaxially grown on the composite buffer layer.

[0039] The composite buffer layer is used to better buffer the lattice mismatch and stress release caused by different materials between the Al2O3 / SiO2 composite PSS substrate and the LED epitaxial bottom layer, and reduce the defects at the interface layer; the LED structure layer is the main working structure of the LED. For example, the LED structure layer may include: a U-shaped GaN layer, an N-type GaN layer, a stress release layer, an electron enrichment layer, a multiple quantum well layer, and a P layer. Among them, the U-shaped GaN layer serves as the LED epitaxial bottom layer to improve the external quantum efficiency and light extraction efficiency; the N-type GaN layer is used to form the N-type region of the LED. The electrons provided by the N-type region recombine with holes in the quantum well to emit light, which is one of the main structures of the LED; the stress release layer is used to release the stress between the lattices; the electron enrichment layer is used to generate an enrichment effect on the electrons in the N-type region; the multiple quantum well layer (MQW: multiple quantum well) refers to a system in which multiple quantum wells are combined. In terms of material structure and growth process, there is no substantial difference between multiple quantum wells and superlattices, except that the superlattice barrier layer is thinner and the coupling between the quantum wells is stronger, forming a miniband, while the barrier layer between the multiple quantum wells is thick, with basically no tunneling coupling and no formation of a miniband. The multiple quantum well structure is mainly applied for its optical properties and is one of the basic structure layers of the LED epitaxial structure; the P layer is used to form the P-type region of the LED and is one of the main structures of the LED.

[0040] The composite buffer layer includes: an aluminum oxynitride / aluminum nitride layer (AlO x N y / AlN) and a silicon oxynitride layer (SiO x N y ). The aluminum oxynitride / aluminum nitride layer covers the alumina in the alumina-silica composite PSS substrate, and the aluminum oxynitride / aluminum nitride layer and the silicon oxynitride layer alternately cover the silica in the alumina-silica composite PSS substrate at intervals; the aluminum oxynitride (AlO x N y)It is connected to the alumina-silica composite PSS substrate, and aluminum nitride (AlN) in the aluminum oxynitride / aluminum nitride layer is connected to the LED structure layer.

[0041] In a schematic embodiment, the thickness of aluminum oxynitride in the aluminum oxynitride / aluminum nitride layer is 30%-60% of the overall thickness of the aluminum oxynitride / aluminum nitride layer. Such a setting is to reduce lattice defects and make the lattice more dense.

[0042] In a schematic embodiment, the thickness of the aluminum oxynitride / aluminum nitride layer is 100-250 Å, and the thickness of the silicon oxynitride layer is 100-300 Å. Such a setting is to better buffer the lattice mismatch and stress release caused by different materials and reduce the defects at the interface layer.

[0043] Figure 7 and Figure 8 is a TEM image of an LED chip based on an alumina-silica composite substrate according to the present application. As can be seen from Figure 8 , the thicknesses of the composite buffer layers on the SiO2 material in the patterned part of the Al2O3 / SiO2 composite PSS substrate are 57 Å and 124 Å, while the thicknesses of the composite buffer layers on the Al2O3 material in the patterned part of the Al2O3 / SiO2 composite PSS substrate are 88 Å and 117 Å. It can be seen that the thickness difference between the two is not significant. And from Figure 7 , no obvious lattice defects can be seen in the SiO2 pattern part of the Al2O3 / SiO2 composite PSS substrate, and its lattice is more dense.

[0044] Based on the above embodiments, the present application further provides a method for manufacturing an LED chip based on an alumina-silica composite substrate. As shown in Figure 9 , the manufacturing method includes:

[0045] S100: Place the Al2O3 / SiO2 composite PSS substrate into a physical vapor deposition (PVD) device, and epitaxially grow an AlO x N y / AlN layer through physical vapor deposition to obtain a first substrate.

[0046] In the PVD device chamber, the sputtering power of the PVD device is set in the range of 3000-4500 W, and the sputtering temperature is set in the range of 500-650 °C. In a nitrogen (N2) atmosphere, argon (Ar) is used to bombard the aluminum (Al) target, and through magnetron sputtering on the surface of the Al2O3 / SiO2 composite PSS substrate substrate, oxygen (O2) is first introduced, and the flow rate of O2 is 2 sccm-6 sccm, and the reaction obtains an AlO x N y thin film epitaxially grown on the Al2O3 / SiO2 composite PSS substrate, as shown inFigure 11 As shown, the time for introducing O2 is 30%-60% of the total time of PVD epitaxial growth, that is, AlO x N y The thickness is 30%-60% of the total thickness of the AlO x N y / AlN layer. Then, the introduction of oxygen is stopped, and an aluminum nitride (AlN) thin film is obtained by reaction and epitaxially grown on the aluminum oxynitride (AlO x N y ) layer, as Figure 12 shown, to obtain a first substrate, which is an Al2O3 / SiO2 composite PSS substrate with a PVD-deposited AlO x N y / AlN layer.

[0047] S200: Place the first substrate into a metal-organic chemical vapor deposition equipment, and grow a silicon oxynitride layer by metal-organic chemical vapor deposition epitaxy to obtain a second substrate, as Figure 10 shown.

[0048] S210: In the MOCVD equipment, heat-treat the first substrate at a first preset temperature.

[0049] Transfer the first substrate to a metal-organic chemical vapor deposition (MOCVD) equipment. In the MOCVD equipment, heat-treat the first substrate in a hydrogen (H2) atmosphere at a first preset temperature. For example, the first preset temperature range is 1050°C - 1150°C; the heat treatment lasts for a first preset time. For example, the first preset time range is 1 - 5 min.

[0050] At the AlO x N y / AlN layer on the SiO2 pattern surface layer, the deposition and growth are difficult. SEM scanning shows that its growth morphology is an irregular discontinuous distribution that is not a thin film. Therefore, heat treatment is required to remove impurities such as water and oxygen on the substrate surface layer. And during the high-temperature process, the AlO x N y / AlN layer composite material can produce an agglomeration effect to form granular particles with a larger interval, thereby exposing a larger area of the SiO2 surface layer, as Figure 13 shown.

[0051] S220: Perform a thermal replacement reaction at a second preset temperature to obtain a SiO x N y layer.

[0052] The atmosphere is converted into a mixed atmosphere of nitrogen (N2) and ammonia (NH3), where N2 is the carrier gas and NH3 is the reaction gas, used to provide a nitrogen (N) source, and a thermal displacement reaction is carried out at a second preset temperature, where the second preset temperature is less than the first preset temperature. For example, the second preset temperature ranges from 800°C to 1000°C, and SiO is obtained through the reaction. x N y The layer is epitaxially grown on the first substrate, as Figure 14 shown; the thermal displacement reaction lasts for a second preset time. For example, the second preset time ranges from 5 min to 20 min, used to control the thickness of the SiO x N y layer on the SiO2 surface and the N substitution component concentration.

[0053] S230: The temperature is decreased to a third preset temperature for annealing treatment to obtain a second substrate.

[0054] Continue to maintain the mixed atmosphere of N2 and NH3, and control the temperature to decrease to the third preset temperature for annealing treatment. The third preset temperature is less than the second preset temperature. For example, the third preset temperature ranges from 550°C to 650°C; the annealing treatment lasts for a third preset time. For example, the third preset time ranges from 20 min to 30 min, used to remove a large amount of H impurities existing on the surface layer of the SiO x N y thin film. After annealing, a second substrate is obtained, as Figure 14 shown. The second substrate is an Al2O3 / SiO2 composite PSS substrate with a composite buffer layer, and the composite buffer layer includes: AlO x N y / AlN layer and SiO x N y layer. The Al2O3 in the Al2O3 / SiO2 composite PSS substrate is covered by the AlO x N y / AlN layer, and the SiO2 in the Al2O3 / SiO2 composite PSS substrate is covered by the staggered and spaced AlO x N y / AlN layer and SiO x N y layer, as Figure 15 shown. For example, the thickness of the epitaxially grown AlO x N y / AlN layer is 100 - 250 Å, and the thickness of the epitaxially grown SiO x N y layer is 100 - 300 Å.

[0055] S300: Epitaxially grow an LED structure layer on the second substrate.

[0056] Exemplarily, LED structure layers such as a U-shaped GaN layer, an N-type GaN layer, a stress release layer, an electron enrichment layer, a multi-quantum well layer, and a P layer can be epitaxially grown on the second substrate in sequence. The epitaxial growth of the LED structure layers can adopt the existing technology, which will not be elaborated in this application.

[0057] Figure 7 and Figure 8 is a TEM image of an LED chip manufactured by using the above manufacturing method. As can be seen from Figure 8 , the thicknesses of the composite buffer layers on the SiO2 material of the Al2O3 / SiO2 composite PSS substrate pattern part are 57 Å and 124 Å, while the thicknesses of the composite buffer layers on the Al2O3 material of the Al2O3 / SiO2 composite PSS substrate pattern part are 88 Å and 117 Å. It can be seen that the thickness difference between the two is not large. And as can be seen from Figure 7 , no obvious lattice defects can be seen in the SiO2 pattern part of the Al2O3 / SiO2 composite PSS substrate, and its lattice is denser. Compared with the LED chips in Figure 5 and Figure 6 , the thickness uniformity of the composite buffer layer on the Al2O3 material and the SiO2 material of the Al2O3 / SiO2 composite PSS substrate has been greatly improved, and there are no obvious lattice defects in the SiO2 pattern part, and its lattice quality has also been greatly improved.

[0058] This application provides an LED chip based on an alumina-silica composite substrate and a manufacturing method thereof. The LED chip includes an alumina-silica composite PSS substrate, a composite buffer layer, and an LED structure layer. Among them, the composite buffer layer is epitaxially grown on the alumina-silica composite PSS substrate, and the LED structure layer is epitaxially grown on the composite buffer layer. The composite buffer layer includes: an aluminum oxynitride / aluminum nitride layer and a silicon oxynitride layer. The aluminum oxynitride / aluminum nitride layer covers the alumina in the alumina-silica composite PSS substrate, and the aluminum oxynitride / aluminum nitride layer and the silicon oxynitride layer are alternately and spacedly covered on the silica in the alumina-silica composite PSS substrate; the aluminum oxynitride in the aluminum oxynitride / aluminum nitride layer is connected to the alumina-silica composite PSS substrate, and the aluminum nitride in the aluminum oxynitride / aluminum nitride layer is connected to the LED structure layer. The composite buffer layer has better thickness uniformity on alumina and silica materials, and can better buffer the lattice mismatch and stress release caused by different materials from the alumina-silica composite PSS substrate to the LED epitaxial bottom layer, and reduce the defects at the interface layer.

[0059] For the similar parts among the embodiments provided in this application, reference can be made to each other. The specific embodiments provided above are only several examples under the general concept of this application and do not constitute a limitation on the protection scope of this application. For those skilled in the art, any other embodiments extended based on the solution of this application without creative efforts fall within the protection scope of this application.

Claims

1. An LED chip based on an alumina-silica composite substrate, characterized in that, Comprising: An alumina-silica composite PSS substrate, a composite buffer layer, and an LED structure layer, wherein the composite buffer layer is epitaxially grown on the alumina-silica composite PSS substrate, and the LED structure layer is epitaxially grown on the composite buffer layer; The composite buffer layer includes: an aluminum oxynitride / aluminum nitride layer and a silicon oxynitride layer, The aluminum oxynitride / aluminum nitride layer covers the alumina in the alumina-silica composite PSS substrate, and the aluminum oxynitride / aluminum nitride layer and the silicon oxynitride layer alternately cover the silica in the alumina-silica composite PSS substrate at intervals; The aluminum oxynitride in the aluminum oxynitride / aluminum nitride layer is connected to the alumina-silica composite PSS substrate, and the aluminum nitride in the aluminum oxynitride / aluminum nitride layer is connected to the LED structure layer.

2. The LED chip based on an alumina-silica composite substrate according to claim 1, wherein The thickness of the aluminum oxynitride in the aluminum oxynitride / aluminum nitride layer is 30%-60% of the overall thickness of the aluminum oxynitride / aluminum nitride layer.

3. The LED chip based on an alumina-silica composite substrate according to claim 1, characterized in that, The thickness of the aluminum oxynitride / aluminum nitride layer is 100-250 Å, and the thickness of the silicon oxynitride layer is 100-300 Å.

4. A method for manufacturing an LED chip based on an alumina-silica composite substrate, which is used to manufacture an LED chip based on an alumina-silica composite substrate as described in claims 1-3, characterized in that, The manufacturing method includes: Placing the alumina-silica composite PSS substrate into a physical vapor deposition device, and epitaxially growing an aluminum oxynitride / aluminum nitride layer by physical vapor deposition to obtain a first substrate; Placing the first substrate into a metal-organic chemical vapor deposition device, and epitaxially growing a silicon oxynitride layer by metal-organic chemical vapor deposition to obtain a second substrate; Epitaxially growing an LED structure layer on the second substrate.

5. A method for manufacturing an LED chip based on an alumina-silica composite substrate according to claim 4, wherein, The step of placing the alumina-silica composite PSS substrate into a physical vapor deposition device and epitaxially growing an aluminum oxynitride / aluminum nitride layer by physical vapor deposition to obtain a first substrate includes: In the chamber of the physical vapor deposition device, in a nitrogen atmosphere, bombarding an aluminum target with argon by magnetron sputtering on the surface of the alumina-silica composite PSS substrate substrate, introducing oxygen, and reacting to obtain an aluminum oxynitride thin film epitaxially grown on the alumina-silica composite PSS substrate; Stop introducing oxygen, and react to obtain an aluminum nitride thin film epitaxially grown on the aluminum oxynitride layer to obtain a first substrate.

6. A method for manufacturing an LED chip based on an alumina-silica composite substrate according to claim 5, characterized in that, The sputtering power of the physical vapor deposition device is set in the range of 3000-4500 W, and the sputtering temperature is set in the range of 500-650 °C; the flow rate of the introduced oxygen is 2 sccm-6 sccm, and the time of introducing oxygen is 30%-60% of the overall time of physical vapor deposition epitaxial growth.

7. A method for manufacturing an LED chip based on an alumina-silica composite substrate according to claim 4, wherein The step of placing the first substrate into a metal-organic chemical vapor deposition device and epitaxially growing a silicon oxynitride layer by metal-organic chemical vapor deposition to obtain a second substrate includes: In the metal-organic chemical vapor deposition device, performing heat treatment on the first substrate in a hydrogen atmosphere at a first preset temperature for a first preset time; Converting the atmosphere into a mixed atmosphere of nitrogen and ammonia, where nitrogen is the carrier gas and ammonia is the reaction gas to provide a nitrogen source, and performing a thermal displacement reaction at a second preset temperature, and reacting to obtain a silicon oxynitride layer epitaxially grown on the first substrate, where the second preset temperature is less than the first preset temperature, and the thermal displacement reaction lasts for a second preset time; Maintain a mixed atmosphere of nitrogen and ammonia, and lower the temperature to the third preset temperature for annealing treatment. The third preset temperature is lower than the second preset temperature, and the annealing treatment lasts for the third preset time to obtain a second substrate.

8. A method for manufacturing an LED chip based on an alumina-silica composite substrate according to claim 7, characterized in that, The first preset temperature range is 1050°C - 1150°C, and the first preset time range is 1 - 5 min; the second preset temperature range is 800°C - 1000°C, and the second preset time range is 5 min - 20 min; the third preset temperature range is 550°C - 650°C, and the third preset time range is 20 min - 30 min.

9. A method for manufacturing an LED chip based on an alumina-silica composite substrate according to claim 4, characterized in that, The thickness of the aluminum oxynitride / aluminum nitride layer grown epitaxially is 100 - 250 Å, and the thickness of the silicon oxynitride layer grown epitaxially is 100 - 300 Å.

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