WO2023092717A1

WO2023092717A1 - Semiconductor epitaxial wafer and manufacturing method therefor

Info

Publication number: WO2023092717A1
Application number: PCT/CN2021/137840
Authority: WO
Inventors: 闫其昂; 王国斌
Original assignee: 江苏第三代半导体研究院有限公司
Priority date: 2021-11-26
Filing date: 2021-12-14
Publication date: 2023-06-01

Abstract

The present application discloses a semiconductor epitaxial wafer and a manufacturing method therefor. The manufacturing method comprises: providing a group III metal organic source mixed precursor containing a uniformly dispersed nano material; and at least coating the mixed precursor between a substrate and a semiconductor epitaxial structure, or coating same between at least two functional layers of the semiconductor epitaxial structure, and then performing, in a mixed atmosphere of a group V element source and a reducing gas, annealing recrystallization on a structure having a group III metal organic source mixed precursor coated layer, so that uniformly distributed nano material and group III-V compound nano growth structure are formed to obtain a semiconductor epitaxial wafer. According to the present application, by means of the group III metal organic source mixed precursor coated layer in combined with the annealing recrystallization, a nucleation center having the uniformly distributed nano material and group III-V compound nano growth structure is formed, and other epitaxial layer structures are grown on this basis, so that the growth quality of epitaxial layers can be improved, and a wide application prospect is achieved.

Description

A kind of semiconductor epitaxial wafer and preparation method thereof

This application is based on and requires the application number 202111427469.X, the title of the invention is "High Quality Semiconductor Epitaxial Wafer and Its Preparation Method", and the application number 202111422413.5, the title of the invention is "A Semiconductor Epitaxial Wafer" submitted on November 26, 2021. Tablets and their preparation methods and applications" of the priority of two Chinese patent applications.

technical field

The application relates to a semiconductor epitaxial wafer and a preparation method thereof, belonging to the technical field of semiconductor material epitaxy.

Background technique

III-V compound semiconductor materials have been widely used in optoelectronic devices, optoelectronic integration, ultra-high-speed microelectronic devices and ultra-high frequency microwave devices and circuits, and have broad prospects. Since III-nitrides are generally heteroepitaxy on heterogeneous substrates such as sapphire or SiC, the lattice constant and thermal mismatch between different materials will generate dislocations or defects, which extend upward with the growth of the epitaxial layer , these dislocations behave as non-radiative recombination centers when the device is working, which affects the efficiency of the device. At the same time, as a leakage channel, the leakage current increases and the device ages rapidly, affecting the working efficiency and life of the device, which restricts its application in the field of semiconductor electronics. In addition, with the unprecedented development of Micro-LED display applications, higher requirements are placed on epitaxial uniformity.

GaN-based light-emitting diode LED is a semiconductor light-emitting device, which has the advantages of long life, low energy consumption, small size, and high reliability. It has become the most promising lighting source and an important trend in leading lighting technology; but it still exists The problem of low luminous intensity and efficiency, further improving the luminous intensity and luminous efficiency of LED is the goal of the development of LED lighting technology.

At present, MOCVD epitaxy of GaN-based semiconductor materials is an epitaxial technology grown on heterogeneous substrates. Due to the mismatch between the lattice and thermal expansion between the substrate and the epitaxial layer, the dislocation density and stress of the epitaxially grown crystal material are high, which is easy Warping cracks and other phenomena appear. These dislocations behave as non-radiative recombination centers when the device is working, which affects the efficiency of the device. Applications in the field of electronics; at the same time, the refractive index difference between GaN material and air is large, and the critical reflection angle is small. Only a small part of the light from the active light-emitting layer is emitted into the air, which further affects the light extraction efficiency. In addition, with the development of semiconductor lighting and display markets, the demand for substrates is increasingly shifting to larger sizes. Warpage cracks caused by residual stress in GaN thick films on heterogeneous substrates such as sapphire with large sizes are also GaN heteroepitaxy. Technology is difficult to overcome, and the wavelength uniformity is also difficult to meet the requirements of Micro-LED, which poses greater difficulties and challenges to the growth of GaN materials.

In view of the problems of low luminous intensity and efficiency in LED lighting technology, and the challenge of growth technology that the stress of heterogeneous substrate epitaxial growth leads to poor quality of luminous wells, the problem of uniform distribution of luminescent layer groups caused by stress affects wavelength uniformity, so It is necessary to propose a new epitaxial structure to improve the stress of the quantum well light-emitting layer and improve the luminous intensity and efficiency of the light-emitting diode.

Contents of the invention

The main purpose of this application is to propose a semiconductor epitaxial wafer and its preparation method based on the current problem of epitaxial defects in heterogeneous growth of semiconductor materials, so as to overcome the shortcomings of the prior art.

In order to realize the aforementioned object of the invention, the technical solutions adopted in this application include:

An embodiment of the present application provides a method for preparing a semiconductor epitaxial wafer, the semiconductor epitaxial wafer includes a substrate, and a semiconductor epitaxial structure, and the preparation method includes:

Provide Group III metal-organic source hybrid precursors containing uniformly dispersed nanomaterials;

Coating the group III metal-organic source mixed precursor at least between the substrate and the semiconductor epitaxial structure, or between at least two functional layers of the semiconductor epitaxial structure, to obtain a group III metal organic source mixed precursor coating layer, and then the structure with Group III metal-organic source mixed precursor coating layer is placed in the MOCVD reaction chamber, and the Group III metal-organic source is introduced, and the group V element source and the reducing gas Annealing and recrystallization are carried out in a mixed atmosphere, thereby forming uniformly distributed nanomaterials and III-V group compound nanometer growth structures, and obtaining semiconductor epitaxial wafers.

In some embodiments, the preparation method specifically includes:

Coating the Group III metal-organic source mixed precursor on the substrate to obtain the Group III metal-organic source mixed precursor coating layer, and then placing the substrate with the Group III metal-organic source mixed precursor coating layer on In the MOCVD reaction chamber, the metal-organic source of group III is introduced, and annealing and recrystallization are carried out in the mixed atmosphere of group V element source and reducing gas, so as to form uniformly distributed nanomaterials and nano-growth structures of group III-V compounds, and obtain Stress relief buffer layer;

growing and forming a semiconductor epitaxial structure on the stress release buffer layer to obtain a semiconductor epitaxial wafer.

In some embodiments, the embodiment of the present application provides a method for preparing a semiconductor epitaxial wafer, the semiconductor epitaxial wafer includes a substrate, a nitride buffer layer, an unintentionally doped nitride layer, an n-type nitride layer, a nitrogen Compound multi-quantum well light-emitting layer, p-type nitride electron blocking layer, p-type nitride layer, the preparation method includes:

Coating the group III metal-organic source mixed precursor at least on any one of the unintentionally doped nitride layer, n-type nitride layer, and p-type nitride layer to obtain the group III metal-organic source mixed precursor coating layer, and then place the composite structure with the mixed precursor coating layer of group III metal-organic source in the MOCVD reaction chamber, pass through the group III metal-organic source, in the mixed atmosphere of group V element source and reducing gas Annealing and recrystallization are carried out to form nucleation centers with evenly distributed nano-growth structures of nanomaterials and III-V compounds, and to obtain a metal-organic source insertion layer.

The embodiment of the present application also provides a semiconductor epitaxial wafer prepared by the aforementioned method.

In some embodiments, the semiconductor epitaxial wafer includes a substrate, on which a stress release buffer layer and a semiconductor epitaxial structure are sequentially formed; wherein, the stress release buffer layer is composed of a group III coating on the surface of the substrate The metal-organic source mixed precursor coating layer is formed by annealing and recrystallization.

In some embodiments, the semiconductor epitaxial wafer includes a substrate, a nitride buffer layer, an unintentionally doped nitride layer, an n-type nitride layer, a nitride multi-quantum well light-emitting layer, a p-type nitride electron blocking layer, The p-type nitride layer, the surface of at least any one of the unintentionally doped nitride layer, n-type nitride layer, and p-type nitride layer is formed with a metal-organic source insertion layer, and the metal-organic source insertion layer is composed of The group III metal-organic source mixed precursor coating layer covered on the surface is formed by annealing and recrystallization.

Compared with the prior art, the present application has significant advantages and beneficial effects, which are embodied in the following aspects:

1) This application provides an epitaxial wafer obtained by spin-coating a metal-organic source with uniformly dispersed nanomaterials and its preparation method. The metal-organic source mixed precursor coating layer is prepared on the substrate by the spin coating method, and the thickness is accurate and accurate. Controlled, stable process, combined with the annealing and recrystallization process in the MOCVD reaction chamber, the metal-organic source coating layer dispersed by nano-materials gradually forms two types of nuclei distribution to provide nucleation centers, the stress of the epitaxial layer is gradually released, and the lateral epitaxial growth is strengthened. The dislocation density of the epitaxial layer is extended, the defect density is reduced, the growth quality of the quantum well light-emitting layer is improved, the leakage performance and luminous efficiency are improved, and the low-stress quantum well light-emitting layer improves the uniformity of the light-emitting wavelength, which can meet the uniform performance requirements for Micro-LED epitaxy ;

2) The preparation method of the semiconductor epitaxial wafer provided by the application spin-coats at least one layer of the unintentionally doped nitride layer, n-type nitride layer and p-type nitride layer mixed precursor coating layer of group III metal-organic source, the The coating layer is annealed and recrystallized under the MOCVD epitaxial process to form a nucleation center with uniform distribution of nanomaterials and III-V compound nano-growth structures, and obtain a metal-organic source insertion layer. On this basis, a nitride epitaxial layer is grown, showing unevenness The uneven rough surface structure can improve the growth quality of the epitaxial layer on the one hand, and improve the light extraction efficiency and external quantum efficiency of the LED on the other hand.

Additional features and advantages of the application will be set forth in the description which follows, and, in part, will be apparent from the description, or can be learned by practicing the detailed description of the application. The objectives and other advantages of the application may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments described in this application. Those skilled in the art can also obtain other drawings based on these drawings without creative work.

FIG. 1 is a schematic diagram of the preparation process of a light-emitting diode epitaxial structure in a typical implementation case of the present application;

Fig. 2 is a schematic diagram of the layered structure of the light-emitting diode epitaxial structure in a typical implementation case of the present application;

3 is a schematic diagram of the layered structure of an LED epitaxial wafer with a specific nitride roughened layer structure in a typical implementation case of the present application, wherein the nitride roughened layer is located on the unintentionally doped nitride layer;

4 is a schematic diagram of the layered structure of an LED epitaxial wafer with a specific nitride roughened layer structure in another typical implementation case of the present application, wherein the nitride roughened layer is located on the n-type nitride layer;

5 is a schematic diagram of the layered structure of an LED epitaxial wafer with a specific nitride roughened layer structure in another typical implementation case of the present application, wherein the nitride roughened layer is located on the p-type nitride layer;

Fig. 6 is a schematic diagram of the preparation process of a high-efficiency LED epitaxial wafer with a low-stress quantum well light-emitting layer in another typical implementation case of the present application;

7 is a schematic diagram of the layered structure of a high-luminous-efficiency LED epitaxial wafer with a low-stress quantum well light-emitting layer in another typical embodiment of the present application.

Explanation of reference numerals: 11-substrate, 12-nitride buffer layer, 13-unintentionally doped nitride layer, 130-unintentionally doped nitride layer with metal-organic source insertion layer, 14-n-type nitride layer, 140-n-type nitride layer with metal-organic source insertion layer, 15-nitride multiple quantum well light-emitting layer, 151-nitride quantum barrier layer, 152-nitride quantum well layer, 16-p-type nitride electron Barrier layer, 17-p-type nitride layer, 170-p-type nitride layer with metal-organic source insertion layer, 100-metal-organic source insertion layer, 200-quantum barrier modification layer, 300-quantum well layer, 2-stress Release the buffer layer.

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, not all of them. The components of the embodiments of the application generally described and illustrated in the figures herein may be arranged and designed in a variety of different configurations. Accordingly, the following detailed description of the embodiments of the application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely represents selected embodiments of the application. Based on the embodiments of the present application, those skilled in the art should understand that: it is still possible to modify the technical solutions of each embodiment, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the corresponding technical solutions Essentially departing from the spirit and scope of the technical solutions of the various embodiments of the present application, and all other embodiments obtained without creative work, all belong to the scope of protection of the present application.

It should be noted that like numerals and letters denote similar items in the following figures, therefore, once an item is defined in one figure, it does not require further definition and explanation in subsequent figures. Meanwhile, in the description of the present application, orientation terms, order terms, etc. are only used to distinguish descriptions, and cannot be understood as indicating or implying relative importance.

An aspect of the embodiments of the present application provides a method for preparing a semiconductor epitaxial wafer, the semiconductor epitaxial wafer includes a substrate, and a semiconductor epitaxial structure, and the preparation method includes:

In some embodiments, the nanomaterials include, but are not limited to, any one or a combination of zero-dimensional nanomaterials, one-dimensional nanomaterials, two-dimensional nanomaterials, three-dimensional nanomaterials, and the like.

Further, the mass ratio of nanomaterials to Group III metal-organic sources in the mixed precursor is less than 1:1.

In some embodiments, the nanomaterials can be nanoparticles, preferably any one or a combination of two or more of metal nanomaterials, non-metallic inorganic nanomaterials, organic compound nanomaterials, etc., and a variety of nanoparticles Coexisting in the dispersion liquid does not react with each other, and still exists in the dispersion liquid as separate nanoparticles.

Further, the shape of the nanomaterial may be any one or a combination of two or more of nanoparticles, nanowires, nanofilms, nanoblocks, etc., but is not limited thereto.

In some embodiments, the nanomaterials (ie nanoparticles) may be Si ₃ N ₄ , SiO ₂ , GaN, AlN, InN, SiC, ScAlN, Al ₂ O ₃ , Si, C, TiC, TiN, WC, WC- _CO , B ₄ C, BN, TiB ₂ , LaF ₃ , MoS ₂ , ZrB ₂ , ZnS, ZnSe, ZnO, Fe ₃ O ₄ , Ta ₂ O ₅ , SnO ₂ , TiO ₂ , ZrO ₂ , Ni, Any one or a combination of two or more of Au, Ag, Fe, Co, Mn, Ti, Mg, Al, Ga, In, polystyrene, perovskite, graphene, etc., but not limited thereto, may also is any other possible nanoparticle.

Further, the nanomaterials preferably include SiN, SiO ₂ , GaN, AlN, InN, SiC, ScAlN, Al ₂ O ₃ , Si, C, TiC, TiN, BN, ZnS, ZnSe, ZnO, TiO ₂ , Ni , Au, Ag, Fe, Co, Mn, Ti, Mg, Al, graphene, etc. any one or a combination of two or more.

Furthermore, the nanomaterial may preferably include any one or a combination of two or more of SiN, GaN, AlN, SiC, ScAlN, Al ₂ O ₃ , TiO ₂ , Ni, Al, Ga, graphene and the like.

Further, the diameter of the nanomaterial is 5-500 nm.

In some embodiments, the group III elements contained in the group III metal-organic source include any one or a combination of two or more of indium (In), gallium (Ga), and aluminum (Al).

Further, the Group III metal-organic source includes a Group III organic compound source, and the Group III organic compound source includes any one or a combination of two or more of an indium source, a gallium source, and an aluminum source.

Wherein, the indium (In) source includes one or more combinations of trimethylindium, triethylindium, and dimethylethylindium, and the gallium (Ga) source includes trimethylgallium (TMG), One or more combinations of triethylgallium and triisopropylgallium, aluminum sources include trimethylaluminum, triethylaluminum, dimethylaluminum alkane, dimethylaluminum hydride, and alane complexes Any one or a combination of two or more, but not limited thereto.

Further, the reducing gas preferably includes H ₂ , but is not limited thereto.

Further, the flow ratio of the group V element source to the reducing gas in the mixed atmosphere is 10:1˜100:1.

In some specific implementation cases, another aspect of the embodiment of the present application provides a method for preparing a semiconductor epitaxial wafer including:

In some embodiments, the group V elements contained in the source of group V elements include any one or a combination of two or more of nitrogen (N), phosphorus (P), and arsenic (As).

Further, the source of group V elements includes any one or a combination of two or more of nitrogen source, phosphorus source, and arsenic source.

Wherein, the nitrogen source includes any one or a combination of two or more of NH ₃ , organic amine compounds, trap compounds, etc., but is not limited thereto. Wherein, the organic amine compound may be an alkylamine, such as tert-butylamine, n-propylamine, etc., and the hydrazine compound may be dimethyl hydrazine, but is not limited thereto.

Wherein, the phosphorus source includes PH ₃ and/or an organic phosphorus source, and the organic phosphorus source includes tert-butyl phosphorus, but is not limited thereto.

Wherein, the arsenic source includes AsH ₃ and/or an organic arsenic source, and the organic arsenic source includes t-butyl arsenic, but is not limited thereto.

Further, the thickness of the group III metal-organic source mixed precursor coating layer is 20-2000 nm.

In some embodiments, the preparation method further includes: sequentially growing an unintentionally doped nitride layer, an n-type nitride layer, a light-emitting layer, an electron blocking layer, and a p-type nitride layer on the stress release buffer layer, A semiconductor epitaxial wafer is produced.

Further, the substrate may be sapphire, silicon carbide, silicon, zinc oxide, gallium nitride or gallium arsenide, but not limited thereto.

In some specific embodiments, in the preparation method, the group III metal-organic source mixed precursor with uniformly dispersed nanomaterials is spin-coated on the substrate, comprising the following steps:

1) Preparation of nanomaterial dispersion

The nanomaterials are added to the dispersing solvent and mixed, and the dispersant is added to prevent the spontaneous aggregation of the nanoparticles due to the high surface energy. Under the condition of ultrasound at a certain temperature, the nanoparticles are uniformly dispersed in the solvent to form a nanomaterial dispersion;

2) Preparation of group III metal-organic source mixed precursors containing uniformly dispersed nanomaterials

The nanomaterial is separated from the solvent, dried quickly, mixed with an appropriate amount of Group III metal-organic source, and under a certain temperature and ultrasonic conditions, a Group III metal-organic source mixed precursor containing uniformly dispersed nanomaterials is obtained;

3) Spin-coating Group III metal-organic source mixed precursors containing uniformly dispersed nanomaterials

Spin-coating the Group III metal-organic source mixed precursor containing uniformly dispersed nanomaterials on the substrate to obtain the Group III metal-organic source mixed precursor coating layer.

Specifically, step 2) specifically includes: uniformly mixing the nanomaterial and the group III metal-organic source, and ultrasonically treating it at 5-40° C. for 10-60 minutes to obtain a group III metal-organic source mixed precursor containing uniformly dispersed nanomaterials.

Specifically, before step 1), the nanomaterials are uniformly dispersed in the dispersing solvent and ultrasonically treated to form a nanomaterial dispersion, and then the nanomaterials are separated from the dispersing solvent and dried, wherein the dispersed The solvent includes ethanol, and the ultrasonic treatment time is 0.5-2 hours; the nanomaterial dispersion liquid also includes a dispersant.

Further, the semiconductor epitaxial wafer is a light emitting diode (LED) epitaxial wafer.

Among them, in some more specific implementation cases, please refer to FIG. 1, the method for preparing the light-emitting diode epitaxial wafer specifically includes the following steps:

1) provide a substrate, the substrate can be sapphire, silicon carbide, silicon, zinc oxide or gallium nitride;

2) In the _N2 atmosphere of the glove box, spin-coat the group III metal-organic source mixed precursor containing uniformly dispersed nanomaterials on the substrate by spin coating, and form a group III metal-organic source with a thickness of 20nm to 2000nm on the substrate. Source mixed precursor coating layer;

3) Place the substrate with the Group III metal-organic source mixed precursor coating layer in the reaction chamber of the MOCVD growth equipment, and use the epitaxial growth process to grow the epitaxial layer as follows:

The substrate with the mixed precursor coating layer of group III metal-organic source is placed in the reaction chamber of the MOCVD growth equipment, the pressure in the reaction chamber is 100-600 torr, and the group III metal-organic source is introduced, and the group III metal The organic source is a Group III organic compound source, the temperature of the reaction chamber is raised to 500-1200°C, and the Group V element source and reducing gas are introduced to carry out annealing and recrystallization for 10s-100s, and then grow to obtain a thickness of 10-100nm. Stress relief buffer layer;

4) growing an unintentionally doped nitride layer with a thickness of 1-4 μm on the stress relief buffer layer, the unintentionally doped nitride layer is an unintentionally doped GaN layer, and the Ga source required for growth It is TMG source, the growth atmosphere is _H2 atmosphere, the growth temperature is 1000-1200℃, and the growth pressure is 100-600torr;

5) growing an n-type nitride layer with a thickness of 1-4 μm on the unintentionally doped nitride layer, the n-type nitride layer is an n-type GaN layer, and the doping concentration of Si is 2×10 ¹⁸ cm ^-3 ～5×10 ¹⁹ cm ^-3 ; the Ga source required for growth is TMG source, the growth atmosphere is H ₂ atmosphere, the growth temperature is 1000～1200℃, and the growth pressure is 100～600torr;

6) Growing a light-emitting layer on the n-type nitride layer, and growing 1 to 20 pairs of InGaN/GaN multi-quantum well light-emitting layers together, and the InGaN/GaN multi-quantum well light-emitting layer includes periodically repeated and alternately grown InGaN quantum wells Layer and GaN quantum barrier layer, the repetition period is 1-20, the thickness of the InGaN quantum well layer is 2-6nm, the Ga source required for growth is TEG source, the In source is TMIn source, and the growth atmosphere is _N2 atmosphere, The growth temperature is 700-900° C., the growth pressure is 200-500 torr; the thickness of the GaN quantum barrier layer is 6-20 nm, the Ga source required for growth is a TEG source, the growth atmosphere is _H2 atmosphere, and the growth temperature is 750-200 nm. 950℃, the growth pressure is 200-500torr;

7) growing an electron blocking layer with a thickness of 15-150 nm on the light-emitting layer, the electron blocking layer is a p-type AlGaN electron blocking layer, the Ga source required for growth is a TMG source, the Al source is a TMAl source, and the growth atmosphere is In _N2 atmosphere, the growth temperature is 950-1050°C, and the growth pressure is 100-200torr;

8) growing a p-type nitride layer with a thickness of 20-200 nm on the electron blocking layer, the p-type nitride layer is a p-type GaN layer, and the doping concentration of Mg is 1×10 ¹⁸ cm ^-3 -5 ×10 ²⁰ cm ^-3 ; the Ga source required for growth is TMG source, the growth atmosphere is H ₂ atmosphere, the growth temperature is 950-1050°C, and the growth pressure is 200-600 torr.

Another aspect of the embodiments of the present application also provides a semiconductor epitaxial wafer prepared by the aforementioned method.

Specifically, the semiconductor epitaxial wafer includes a substrate, on which a stress relief buffer layer and a semiconductor epitaxial structure are sequentially formed; wherein, the stress relief buffer layer is composed of a group III metal-organic source covered on the surface of the substrate The mixed precursor coating layer is formed by annealing and recrystallization.

An aspect of the embodiment of the present application provides a semiconductor epitaxial wafer, including a substrate, on which a stress relief buffer layer and a semiconductor epitaxial structure are sequentially formed; wherein, the stress relief buffer layer is formed by covering the substrate The Group III metal-organic source mixed precursor coating layer on the surface is formed by annealing and recrystallization.

Further, the metal-organic source coating layer has a thickness of 20 nm to 2000 nm.

Further, the nanomaterials include, but are not limited to, any one or a combination of zero-dimensional nanomaterials, one-dimensional nanomaterials, two-dimensional nanomaterials, and three-dimensional nanomaterials.

Further, the semiconductor epitaxial wafer includes a substrate and a stress release buffer layer, an unintentionally doped nitride layer, an n-type nitride layer, a light-emitting layer, an electron blocking layer, and a p-type nitride layer sequentially located thereon.

Specifically, as shown in FIG. 2, the semiconductor epitaxial wafer of the present application includes a substrate 11 and a stress release buffer layer 2, an unintentionally doped nitride layer 13, an n-type nitride layer 14, a light emitting layer ( For example, a nitride multi-quantum well light-emitting layer 15 ), an electron blocking layer (such as a p-type nitride electron blocking layer 16 ), and a p-type nitride layer 17 .

Wherein, the substrate 11 may be sapphire, silicon carbide, silicon, zinc oxide, gallium nitride, gallium arsenide or other material substrates, but not limited thereto.

Further, the stress relief buffer layer 2 is formed by annealing and recrystallizing the coating layer of the Group III metal-organic source mixed precursor obtained by spin-coating the Group III metal-organic source mixed precursor containing uniformly dispersed nanomaterials, and the Group III metal The thickness of the organic source mixed precursor coating layer is 20-2000nm.

Further, the unintentionally doped nitride layer 13 is an unintentionally doped GaN layer with a thickness of 1-4 μm.

Further, the n-type nitride layer 14 is an n-type GaN layer with a thickness of 1-4 μm, and the doping concentration of Si is 2×10 ¹⁸ cm ⁻³ to ⁵ ×10 ¹⁹ cm ⁻³ .

Further, the light-emitting layer is cyclic growth of 1 to 20 pairs of nitride multi-quantum well light-emitting layers 15 (such as InGaN/GaN multi-quantum well light-emitting layers), and the InGaN/GaN multi-quantum well light-emitting layers include periodically repeated alternate growth of nitrogen The nitride quantum well layer 152 and the nitride quantum barrier layer 151, the thickness of the nitride quantum well layer 152 (eg InGaN quantum well layer) is 2-6 nm, and the thickness of the nitride quantum barrier layer 151 (eg GaN quantum barrier layer) is 6 nm. ~20nm.

Further, the electron blocking layer (such as the p-type nitride electron blocking layer 16 ) is a p-type AlGaN electron blocking layer with a thickness of 15-150 nm.

Further, the p-type nitride layer 17 is a p-type GaN layer with a thickness of 20-200 nm, and the doping concentration of Mg is 1×10 ¹⁸ cm ⁻³ to 5×10 ²⁰ cm ⁻³ .

In some specific implementation cases, an aspect of the embodiments of the present application provides a method for preparing a semiconductor epitaxial wafer, the semiconductor epitaxial wafer includes a substrate, a nitride buffer layer, an unintentionally doped nitride layer, n Type nitride layer, nitride multi-quantum well light-emitting layer, p-type nitride electron blocking layer, p-type nitride layer, the preparation method includes:

Coating the group III metal-organic source mixed precursor at least on any one of the unintentionally doped nitride layer, n-type nitride layer, and p-type nitride layer to obtain the group III metal-organic source mixed precursor coating layer, and then place the composite structure with the mixed precursor coating layer of group III metal-organic source in the MOCVD reaction chamber, pass through the group III metal-organic source, in the mixed atmosphere of group V element source and reducing gas Annealing and recrystallization are performed to form nucleation centers with uniform distribution of nanomaterials and III-V group compound nanogrowth structures, and to obtain a metal-organic source insertion layer.

In some embodiments, the group V elements contained in the source of group V elements include nitrogen (N) elements, the source of group V elements includes a nitrogen source, and the nitrogen source includes NH ₃ , organic amine compounds, well-type compounds etc., any one or a combination of two or more, but not limited thereto. Wherein, the organic amine compound may be an alkylamine, such as tert-butylamine, n-propylamine, etc., and the hydrazine compound may be dimethyl hydrazine, but is not limited thereto.

Wherein, the types and other limitations of the nanomaterials are as described above, and will not be repeated here.

In some specific implementation cases, when the group III metal-organic source mixed precursor is coated on the unintentionally doped nitride layer, the preparation method of the semiconductor epitaxial wafer specifically includes:

sequentially growing a nitride buffer layer and an unintentional doped nitride layer on the substrate;

Coating the group III metal-organic source mixed precursor on the unintentionally doped nitride layer to obtain the group III metal-organic source mixed precursor coating layer, and then coating the group III metal-organic source mixed precursor coating layer The composite structure is placed in the MOCVD reaction chamber, and the Group III metal-organic source is introduced, and annealing and recrystallization are performed in the mixed atmosphere of the V group element source and the reducing gas, thereby forming nanomaterials and III-V compound nano-growth structures Uniformly distributed nucleation centers, resulting in metal-organic source insertion layers;

And, continue to grow n-type nitride layer, nitride multi-quantum well light-emitting layer, p-type nitride electron blocking layer, p-type nitride layer on the metal-organic source insertion layer to obtain the low-stress quantum well light-emitting layer High-efficiency semiconductor epitaxial wafers.

Wherein, in some more specific implementation cases, when the group III metal-organic source mixed precursor is coated on the unintentionally doped nitride layer, the preparation method of the semiconductor epitaxial wafer specifically includes the following steps :

1) Provide a substrate, and grow a nitride buffer layer with a thickness of 20-60 nm on the substrate under the growth condition of a temperature of 400-600° C.; the substrate can be sapphire, silicon carbide, silicon, oxide Zinc or gallium nitride, etc., but not limited thereto;

2) growing an unintentionally doped nitride layer with a thickness of 2-4 μm on the nitride buffer layer under the growth conditions of a temperature of 1040-1100° C. and a pressure of 100-300 torr;

3) In the _N2 atmosphere, the group III metal-organic source mixed precursor is coated on the unintentionally doped nitride layer by spin coating, and a thickness of 10-1000 nm is formed on the unintentionally doped nitride layer. Group III metal-organic source mixed precursor coating layer;

4) Place the composite structure with the mixed precursor coating layer of group III metal-organic source in the reaction chamber of the MOCVD growth equipment, the pressure in the reaction chamber is 100-600 torr, and the group III metal-organic source is introduced, and the group III The group metal organic source is a group III organic compound source, the reaction chamber is heated to 500-1200°C, and the source of group V elements and reducing gas are introduced to carry out annealing and recrystallization for 10s-100s, and then grow to obtain a thickness of 1-200°C. 100nm metal-organic source insertion layer;

5) growing an n-type nitride layer with a thickness of 2-4 μm on the metal-organic source insertion layer under the growth conditions of a temperature of 1040-1070° C. and a pressure of 100-200 torr, with a doping concentration of 2×10 ¹⁸ cm ^-3 ～5×10 ¹⁹ cm ^-3 ;

6) Under the growth conditions of a temperature of 750-900° C. and a pressure of 100-300 torr, a nitride multi-quantum well light-emitting layer is grown on the n-type nitride layer, and the nitride multi-quantum well light-emitting layer includes a periodic The nitride quantum well layer and the nitride quantum barrier layer are repeatedly grown alternately, the growth period is 1-20, the thickness of the nitride quantum well layer is 2-6 nm, and the thickness of the nitride quantum barrier layer is 6-20 nm;

7) growing a p-type nitride electron blocking layer with a thickness of 15-150 nm on the nitride multi-quantum well light-emitting layer under the growth conditions of a temperature of 800-1000° C. and a pressure of 100-400 torr;

8) growing a p-type nitride layer with a thickness of 20-200 nm on the p-type nitride electron blocking layer under the growth conditions of a temperature of 800-1000° C. and a pressure of 100-400 torr, with a doping concentration of 1× 10 ¹⁸ cm ^-3 ~5×10 ²⁰ cm ^-3 .

Among them, the nitride buffer layer, the unintentionally doped nitride layer, the n-type nitride layer, the nitride multi-quantum well light-emitting layer, the p-type nitride electron blocking layer, the p-type The material of the nitride layer includes any one or a combination of two or more of GaN, AlN, InN, InGaN, AlInN, AlGaN, AlInGaN, etc., but is not limited thereto.

In some specific embodiments, in the preparation method, the method of spin-coating the group III metal-organic source mixed precursor with uniformly dispersed nanomaterials comprises the following steps:

1) Preparation of nanomaterial dispersion

Nanomaterials are added to the dispersing solvent and mixed, adding a dispersant to prevent the spontaneous aggregation of nanoparticles due to high surface energy, and uniformly dispersing the nanomaterials in the solvent to form a nanomaterial dispersion under ultrasonic conditions at a certain temperature;

On any one of the unintentionally doped nitride layer, n-type nitride layer, and p-type nitride layer, spin-coat the group III metal-organic source mixed precursor containing uniformly dispersed nanomaterials to obtain a group III metal-organic source mixture Precursor coating layer.

In some specific implementation cases, when the group III metal-organic source mixed precursor is coated on the n-type nitride layer, the preparation method of the semiconductor epitaxial wafer specifically includes:

sequentially growing a nitride buffer layer, an unintentionally doped nitride layer and an n-type nitride layer on the substrate;

Coating the Group III metal-organic source mixed precursor on the n-type nitride layer to obtain the Group III metal-organic source mixed precursor coating layer, and then compounding the Group III metal-organic source mixed precursor coating layer The structure is placed in the MOCVD reaction chamber, and the group III metal organic source is passed through, and annealing and recrystallization are carried out in the mixed atmosphere of the V group element source and the reducing gas, so as to form nanomaterials and III-V compound nano-growth structures with uniform distribution The nucleation center of the metal-organic source intercalation layer is obtained;

growing a quantum barrier modification layer on the surface of the metal-organic source insertion layer, and then growing a quantum well layer to form a first light-emitting layer;

And, continue to grow nitride multi-quantum well light-emitting layer, p-type nitride electron blocking layer, p-type nitride layer, and produce high light-efficiency semiconductor epitaxial wafer with low-stress quantum well light-emitting layer.

Among them, in some more specific implementation cases, when the group III metal-organic source mixed precursor is coated on the n-type nitride layer, please refer to Figures 6 and 7, a low-stress The preparation method of the high light-efficiency semiconductor epitaxial wafer of the quantum well light-emitting layer specifically includes the following steps:

1) Provide a substrate 11, and grow a nitride buffer layer 12 with a thickness of 20-60 nm on the substrate under the growth condition of a temperature of 400-600° C.; the substrate can be sapphire, silicon carbide, silicon , zinc oxide or gallium nitride, etc., but not limited thereto;

2) growing an unintentionally doped nitride layer 13 with a thickness of 2-4 μm on the nitride buffer layer 12 under the growth conditions of a temperature of 1040-1100° C. and a pressure of 100-300 torr;

3) growing an n-type nitride layer 14 with a thickness of 2-4 μm on the unintentionally doped nitride layer 13 under the growth conditions of a temperature of 1040-1070° C. and a pressure of 100-200 torr, with a doping concentration of 2×10 ¹⁸ cm ^-3 ～5×10 ¹⁹ cm ^-3 ;

4) In _N2 atmosphere, apply the group III metal-organic source mixed precursor on the n-type nitride layer 14 by spin-coating method, and form a III layer with a thickness of 10-1000 nm on the n-type nitride layer 14. Group metal-organic source mixed precursor coating layer;

5) Place the composite structure with the mixed precursor coating layer of group III metal-organic source in the reaction chamber of the MOCVD growth equipment, the pressure in the reaction chamber is 100-600 torr, feed the group III metal-organic source, and the III The group metal organic source is a group III organic compound source, the reaction chamber is heated to 500-1200°C, and the source of group V elements and reducing gas are introduced to carry out annealing and recrystallization for 10s-100s, and then grow to obtain a thickness of 1-200°C. 100nm metal-organic source insertion layer 100;

6) Under the growth conditions of a temperature of 700-950° C. and a pressure of 50-350 torr, a quantum barrier modification layer 200 with a thickness of 10 nm to 500 nm is formed on the surface of the metal-organic source insertion layer 100; ~6nm quantum well layer 300 to form the first light-emitting layer;

7) Under the growth conditions of a temperature of 750-900° C. and a pressure of 100-300 torr, grow a nitride multi-quantum well light-emitting layer 15 on the quantum well layer, and the nitride multi-quantum well light-emitting layer includes periodically repeated Alternately grown nitride quantum well layers 152 and nitride quantum barrier layers 151, the repeated growth period of the light-emitting layer is 1-20, the thickness of the nitride quantum well layer 152 is 2-6 nm, and the thickness of the nitride quantum barrier layer 151 is 6~20nm;

8) growing a p-type nitride electron blocking layer 16 with a thickness of 15-150 nm on the nitride multi-quantum well light-emitting layer 15 under the growth conditions of a temperature of 800-1000° C. and a pressure of 100-400 torr;

9) growing a p-type nitride layer 17 with a thickness of 20-200 nm on the p-type nitride electron blocking layer 16 under the growth conditions of a temperature of 800-1000° C. and a pressure of 100-400 torr, with a doping concentration of 1×10 ¹⁸ cm ^-3 to 5×10 ²⁰ cm ^-3 .

Wherein, the nitride buffer layer, the unintentionally doped nitride layer, the n-type nitride layer, the nitride multi-quantum well light-emitting layer, the p-type nitride electron blocking layer, the p-type nitrogen The material of the compound layer includes any one or a combination of two or more of GaN, AlN, InN, InGaN, AlInN, AlGaN, AlInGaN, etc., but is not limited thereto.

In some embodiments, step 6) includes: growing and adjusting the thickness of the quantum barrier modification layer to be 10nm-500nm by using a lateral epitaxial growth process.

In other embodiments, step 6) includes: growing and adjusting the thickness of the quantum barrier modification layer to be 10nm-500nm by using a combination of vertical epitaxy and lateral epitaxy.

Wherein, the method of spin-coating the Group III metal-organic source mixed precursor with uniformly dispersed nanomaterials is as described above, and will not be repeated here.

In the above technical scheme, the present application coats the group III metal-organic source mixed precursor with dispersed nanoparticles on the n-type nitride layer to obtain a metal-organic source mixed precursor spin coating, and then combines annealing and recrystallization to form nanomaterials On the one hand, the metal-organic source insertion layer acts as a buffer layer for the stress release layer, the thickness is precisely controllable, and the process is stable. Expansion, improve the capacitance characteristics of LED, improve the antistatic ability, on the other hand, form a quantum barrier modification layer on the metal-organic source insertion layer, adjust the longitudinal growth of the quantum well modification layer, and form a light-emitting layer with quantum dots, which can increase the light emission of the light-emitting layer At the same time, the QCSE (Stark effect) is reduced by using the quantum dot confinement effect, and the non-radiative recombination is reduced to improve the coincidence efficiency of electrons and holes. Furthermore, the low-stress quantum well light-emitting layer makes the components of the quantum well layer evenly distributed. It can improve the uniformity of luminous wavelength, and can meet the uniform performance requirements for Micro-LED epitaxy and the preparation of Micro-LED epitaxy.

In some specific implementation cases, when the group III metal-organic source mixed precursor is coated on the p-type nitride layer, the preparation method of the semiconductor epitaxial wafer specifically includes:

On the substrate, sequentially grow a nitride buffer layer, an unintentionally doped nitride layer, an n-type nitride layer, a nitride multi-quantum well light-emitting layer, a p-type nitride electron blocking layer, and a p-type nitride front layer;

Coating the Group III metal-organic source mixed precursor on the p-type nitride front layer to obtain the Group III metal-organic source mixed precursor coating layer, and then applying the Group III metal-organic source mixed precursor coating layer The composite structure is placed in the MOCVD reaction chamber, and the Group III metal-organic source is introduced, and annealing and recrystallization are carried out in the mixed atmosphere of the V group element source and the reducing gas, so as to form nanomaterials and III-V compounds with a uniform nano-growth structure Distributed nucleation centers, resulting in metal-organic source insertion layers;

epitaxially growing a p-type nitride rear layer on the surface of the metal-organic source insertion layer;

And, performing annealing treatment on the obtained epitaxial structure to prepare a semiconductor epitaxial wafer with low ohmic contact p-type nitride.

Among them, in some more specific implementation cases, when the group III metal-organic source mixed precursor is coated on the p-type nitride layer, the p-type nitride semiconductor epitaxial wafer with low ohmic contact The preparation method specifically comprises the following steps:

3) growing an n-type nitride layer with a thickness of 2-4 μm on the unintentionally doped nitride layer under the growth conditions of a temperature of 1040-1070° C. and a pressure of 100-200 torr, with a doping concentration of 2× 10 ¹⁸ cm ^-3 ～5×10 ¹⁹ cm ^-3 ;

4) Under the growth conditions of a temperature of 750-900° C. and a pressure of 100-300 torr, a nitride multi-quantum well light-emitting layer is grown on the n-type nitride layer, and the nitride multi-quantum well light-emitting layer includes a periodic The nitride quantum well layer and the nitride quantum barrier layer are repeatedly grown alternately, the growth period is 1-20, the thickness of the nitride quantum well layer is 2-6 nm, and the thickness of the nitride quantum barrier layer is 6-20 nm;

5) growing a p-type nitride electron blocking layer with a thickness of 15-150 nm on the nitride multi-quantum well light-emitting layer under the growth conditions of a temperature of 800-1000° C. and a pressure of 100-400 torr;

6) growing a p-type nitride front layer with a thickness of 20-200 nm on the p-type nitride electron blocking layer under the growth conditions of a temperature of 800-1000° C. and a pressure of 100-400 torr, with a doping concentration of 1 ×10 ¹⁸ cm ^-3 ～5×10 ²⁰ cm ^-3 ;

7) In _N2 atmosphere, apply the group III metal-organic source mixed precursor on the p-type nitride front layer by spin coating method, and form a III layer with a thickness of 10 nm to 1000 nm on the p-type nitride front layer. Group metal-organic source mixed precursor coating layer;

8) Place the composite structure with the mixed precursor coating layer of group III metal-organic source in the reaction chamber of the MOCVD growth equipment, the pressure in the reaction chamber is 100-600 torr, and the group III metal-organic source is introduced, and the group III The group metal organic source is a group III organic compound source, the reaction chamber is heated to 500-1200°C, and the source of group V elements and reducing gas are introduced to carry out annealing and recrystallization for 10s-100s, and then grow to obtain a thickness of 1-200°C. 100nm metal-organic source insertion layer;

9) Under the growth conditions of a temperature of 800-1000° C. and a pressure of 100-400 torr, a p-type nitride rear layer with a thickness of 2-20 nm is grown on the metal-organic source insertion layer, and the doping concentration is 1×10 ¹⁸ cm ^-3 ～5×10 ²⁰ cm ^-3 ;

10) Place the obtained epitaxial structure in a mixed atmosphere of oxidizing gas, and perform annealing treatment at 350-950° C. for 1-60 min, to obtain a p-type nitride semiconductor epitaxial wafer with low ohmic contact.

Wherein, in step 1) to step 9), the nitride buffer layer, unintentionally doped nitride layer, n-type nitride layer, nitride multi-quantum well light-emitting layer, p-type nitride electron blocking layer, p-type The material of the nitride front layer and the p-type nitride rear layer includes any one or a combination of two or more of GaN, AlN, InN, InGaN, AlInN, AlGaN, AlInGaN, etc., but is not limited thereto.

In the above technical scheme, the present application coats the group III metal-organic source mixed precursor with dispersed nanoparticles on the p-type nitride layer, and then anneals and recrystallizes under the MOCVD epitaxy process to form nanomaterials and group III-V The evenly distributed nucleation center of the compound nano-growth structure presents an uneven roughened surface structure. On the one hand, the roughened structure improves the light output efficiency and external quantum efficiency of the LED. At the same time, the roughened structure has a greater contact with the transparent conductive layer of the LED chip. Area, form better current spread, improve LED luminous intensity and internal quantum efficiency; on the other hand, nanoparticles with metal-organic source mixed precursor coating layer form nano-oxide with _O2 during annealing process, reducing the transparent electrode The Schottky barrier height between the p-type nitride epitaxial layer, combined with the H atoms in the p-type nitride layer, improves the p-type doping ionization efficiency and hole concentration on the surface of the p-type nitride layer, and reduces the ohmic contact Resistors can improve LED hole injection, enhance luminous efficiency, and can also reduce operating voltage and improve reliability.

Another aspect of the embodiment of the present application also provides a semiconductor epitaxial wafer prepared by the aforementioned method, including a substrate, a nitride buffer layer, an unintentionally doped nitride layer, an n-type nitride layer, and a nitride multi-quantum well light-emitting layer , p-type nitride electron blocking layer, p-type nitride layer, at least any one of the unintentionally doped nitride layer, n-type nitride layer, and p-type nitride layer is formed with a metal-organic source insertion layer on the surface , the metal-organic source insertion layer is formed by annealing and recrystallization of the Group III metal-organic source mixed precursor coating layer covered on its surface.

In some specific implementation cases, when the group III metal-organic source mixed precursor is coated on the unintentionally doped nitride layer, the formed metal-organic source insertion layer is located on the unintentionally doped nitride layer, As shown in Figure 3, the layered structure of the prepared semiconductor epitaxial wafer includes from bottom to top: substrate 11, nitride buffer layer 12, unintentionally doped nitride layer 130 with metal-organic source insertion layer, n-type nitrogen Compound layer 14, nitride multi-quantum well light-emitting layer 15, p-type nitride electron blocking layer 16, p-type nitride layer 17.

In other specific implementation cases, when the Group III metal-organic source mixed precursor is coated on the n-type nitride layer, the formed metal-organic source insertion layer is located on the n-type nitride layer, as shown in Figure 4 As shown, the layered structure of the prepared semiconductor epitaxial wafer includes, from bottom to top, a substrate 11, a nitride buffer layer 12, an unintentionally doped nitride layer 13, and an n-type nitride layer 140 with a metal-organic source insertion layer. , a nitride multi-quantum well light-emitting layer 15 , a p-type nitride electron blocking layer 16 , and a p-type nitride layer 17 .

In other specific implementation cases, when the group III metal-organic source mixed precursor is coated on the p-type nitride layer, the formed metal-organic source insertion layer is located on the p-type nitride layer, as shown in Figure 5 As shown, the layered structure of the prepared semiconductor epitaxial wafer includes from bottom to top: substrate 11, nitride buffer layer 12, unintentionally doped nitride layer 13, n-type nitride layer 14, nitride multi-quantum well light emitting Layer 15, p-type nitride electron blocking layer 16, p-type nitride layer 170 with metal organic source insertion layer.

Further, the substrate 11 may be sapphire, silicon carbide, silicon, zinc oxide or gallium nitride, etc., but not limited thereto.

Further, the material of the nitride buffer layer 12 may include any one or a combination of two or more of GaN, AlN, AlGaN, etc., and the thickness is 20-60 nm.

Further, the unintentionally doped nitride layer 13 is an unintentionally doped GaN layer with a thickness of 2-4 μm.

Further, the n-type nitride layer 14 is an n-type GaN layer with a thickness of 2-4 μm, and the doping concentration of Si is 2×10 ¹⁸ cm ⁻³ to 5×10 ¹⁹ cm ⁻³ .

Further, the nitride multi-quantum well light-emitting layer 15 is an InGaN/GaN multi-quantum well light-emitting layer, and the InGaN/GaN multi-quantum well light-emitting layer includes InGaN quantum well layers and GaN quantum barrier layers that are periodically and alternately grown, The repeated growth period is 1-20, the thickness of the InGaN quantum well layer is 2-6 nm, and the thickness of the GaN quantum barrier layer is 6-20 nm.

Further, the p-type nitride electron blocking layer is a p-type AlGaN electron blocking layer with a thickness of 15-150 nm.

Further, the p-type nitride layer is a p-type GaN layer with a thickness of 20-200 nm, and the doping concentration of Mg is 1×10 ¹⁸ cm ⁻³ to 5×10 ²⁰ cm ⁻³ .

Example 1

1) Preparation of Ni nanoparticle dispersion

Using absolute ethanol, add 30% by mass fraction of nano-Ni powder with a diameter of 30 to 80 nm, add 0.15% by mass fraction of citric acid dispersant, and sonicate for 2 hours at room temperature;

2) Preparation of Ni nanoparticles TMG source

The Ni nanoparticles were separated from the solvent, quickly dried and immediately mixed with a high-purity TMG source. The mass fraction of Ni nanoparticles was 40%, and ultrasonicated at 40°C for 60 minutes to obtain a TMG source mixed precursor with uniformly dispersed Ni nanoparticles;

3) Spin coating Ni nanoparticles TMG source mixed precursor

In the _N2 atmosphere of the glove box, the Ni nanoparticles TMG source mixed precursor was spin-coated on the sapphire substrate at a speed of 4000rpm by the spin-coating method of the homogenizer, and uniformly dispersed Ni nanoparticles with a thickness of 30nm were formed on the substrate. TMG source mixed precursor coating layer;

4) Growth of LED epitaxial wafers on TMG source mixed precursor coating layer

①Place the substrate 11 with the TMG source mixed precursor coating layer dispersed with Ni nanoparticles in the MOCVD reaction chamber, set the pressure to 500torr, feed the TMG source, set the temperature rise to 1060°C, and feed NH ₃ and H ₂ annealed and recrystallized for 10s, the flow ratio of NH ₃ and H ₂ was 10:1, and the GaN stress relief buffer layer 2 was grown;

② On the GaN stress release buffer layer 2, under the condition of temperature of 1080°C and growth pressure of 200torr, an unintentionally doped nitride layer 13 with a thickness of 4 μm is grown, which is an unintentionally doped GaN layer, and the required Ga The source is TMG source, and the growth atmosphere is _H2 atmosphere;

③ On the unintentionally doped nitride layer 13, under the conditions of a temperature of 1060° C. and a growth pressure of 200 torr, grow an n-type nitride layer 14 with a thickness of 1 μm, which is an n-type GaN layer, and the doping concentration of Si is 8×10 ¹⁸ cm ^-3 , the Ga source required for growth is TMG source, and the growth atmosphere is H ₂ atmosphere;

④ On the n-type nitride layer 14, grow a light-emitting layer, in order to repeatedly grow 6 pairs of InGaN/GaN multi-quantum well light-emitting layers, the thickness of the InGaN quantum well layer is 3nm, the growth temperature is 750°C, the growth pressure is 200torr, and the growth atmosphere Switch to N ₂ atmosphere, the thickness of the GaN quantum barrier layer is 11nm, the growth temperature is 810°C, the growth atmosphere is switched to H ₂ atmosphere, the growth pressure is 200torr, the Ga source required for growth is TEGa, and the In source is TMIn;

⑤On the InGaN/GaN multi-quantum well light-emitting layer, under the condition of temperature of 950°C and growth pressure of 200torr, an electron blocking layer with a thickness of 25nm is grown, which is a p-type AlGaN electron blocking layer, and the Ga The source is TMG source, the Al source is TMAl, and the growth atmosphere is _N2 atmosphere;

⑥ On the electron blocking layer, grow a p-type nitride layer 17 with a thickness of 50 nm under the conditions of a temperature of 950°C and a growth pressure of 200 torr, which is a p-type GaN layer with a Mg doping concentration of 5×10 ¹⁹ cm ^{- 3.} The Ga source required for growth is TMG source, and the growth atmosphere is switched to H ₂ atmosphere.

Example 2

1) Preparation of Ni nanoparticle dispersion

2) Preparation of Ni nanoparticles TMG source

3) Spin coating Ni nanoparticles TMG source mixed precursor

In the _N2 atmosphere of the glove box, the Ni nanoparticle TMG source mixed precursor was spin-coated on the sapphire substrate at a speed of 4000rpm by the spin coating method of the homogenizer, and a uniformly dispersed Ni nanoparticle with a thickness of 800nm was formed on the substrate. TMG source mixed precursor coating layer;

4) Growth of LED epitaxial wafers on TMG source mixed precursor coating layer

① Place the substrate 11 with the TMG source mixed precursor coating layer dispersed with Ni nanoparticles in the MOCVD reaction chamber, set the pressure to 300torr, feed the TMG source, set the temperature rise to 1200°C, and feed NH ₃ and H ₂ annealed and recrystallized for 40 seconds, the flow ratio of NH ₃ and H ₂ was 20:1, and the GaN stress relief buffer layer 2 was grown;

② On the GaN stress release buffer layer 2, under the conditions of temperature of 1080°C and growth pressure of 200torr, an unintentionally doped nitride layer 13 with a thickness of 2.5 μm is grown, which is an unintentionally doped GaN layer, and the required Ga source is TMG source, growth atmosphere is _H2 atmosphere;

③ On the unintentionally doped nitride layer 13, under the conditions of a temperature of 1060°C and a growth pressure of 200torr, grow an n-type nitride layer 14 with a thickness of 2.5 μm, which is an n-type GaN layer, and the doping concentration of Si is is 8×10 ¹⁸ cm ^-3 , the Ga source required for growth is TMG source, and the growth atmosphere is H ₂ atmosphere;

④Grow a light-emitting layer on the n-type nitride layer 14, in order to repeatedly grow 6 pairs of InGaN/GaN multi-quantum well light-emitting layers, the thickness of the InGaN quantum well layer is 3nm, the growth temperature is 750°C, and the growth atmosphere is switched to _N2 atmosphere , the growth pressure is 200torr, the thickness of the GaN quantum barrier layer is 11nm, the growth temperature is 810°C, the growth atmosphere is switched to H ₂ atmosphere, the growth pressure is 200torr, the Ga source required for growth is TEGa, and the In source is TMIn;

Example 3

1) Preparation of Ni nanoparticle dispersion

2) Preparation of Ni nanoparticles TMG source

The Ni nanoparticles were separated from the solvent, quickly dried and immediately mixed with a high-purity TMG source. The mass fraction of the Ni nanoparticles was 40%, and ultrasonicated at 25°C for 30 minutes to obtain a TMG source mixed precursor with uniformly dispersed Ni nanoparticles;

3) Spin coating Ni nanoparticles TMG source mixed precursor

In the _N2 atmosphere of the glove box, the Ni nanoparticle TMG source mixed precursor was spin-coated on the sapphire substrate at a speed of 4000rpm by the spin coating method of the homogenizer, and uniformly dispersed Ni nanoparticles with a thickness of 1800nm were formed on the substrate. TMG source mixed precursor coating layer;

4) Growth of LED epitaxial wafers on TMG source mixed precursor coating layer

① Place the substrate 11 with the TMG source mixed precursor coating layer of dispersed Ni nanoparticles in the MOCVD reaction chamber, set the pressure to 200torr, feed the TMG source, set the temperature rise to 1200°C, and feed NH ₃ and H ₂ annealed and recrystallized for 100s, the flow ratio of NH ₃ and H ₂ was 50:1, and the GaN stress relief buffer layer 2 was grown;

② On the GaN stress release buffer layer 2, under the condition of temperature of 1080°C and growth pressure of 200torr, an unintentionally doped nitride layer 13 with a thickness of 1 μm is grown, which is an unintentionally doped GaN layer, and the required Ga The source is TMG source, and the growth atmosphere is _H2 atmosphere;

③ On the unintentionally doped nitride layer 13, under the conditions of a temperature of 1060° C. and a growth pressure of 200 torr, grow an n-type nitride layer 14 with a thickness of 4 μm, which is an n-type GaN layer, and the doping concentration of Si is 8×10 ¹⁸ cm ^-3 , the Ga source required for growth is TMG source, and the growth atmosphere is H ₂ atmosphere;

④ On the n-type nitride layer 14, grow a light-emitting layer, in order to repeatedly grow 8 pairs of InGaN/GaN multi-quantum well light-emitting layers, the thickness of the InGaN quantum well layer is 3nm, the growth temperature is 750°C, and the growth atmosphere is switched to _N2 atmosphere , the growth pressure is 300torr, the thickness of the GaN quantum barrier layer is 11nm, the growth temperature is 810°C, the growth atmosphere is switched to H ₂ atmosphere, the growth pressure is 300torr, the Ga source required for growth is TEGa, and the In source is TMIn;

The surface roughness Ra of the LED epitaxial wafer obtained in Example 1, Example 2 and Example 3 is all less than 0.7, the thickness uniformity of the epitaxial layer is less than 2%, the half-maximum width of the 470nm blue light wave in the photoluminescence PL test is all less than 18nm, and the wavelength is uniform The std is less than 1.0nm, which can meet the wavelength uniformity requirements of miro-LED.

The experiment found that as the thickness of the unintentionally doped nitride layer increased from Example 1 to Example 3, the surface defects of the epitaxial wafer decreased from 5×10 ⁸ cm ^-2 to 1×10 ⁸ cm ^-2 , and the experiment found that as the n-type The thickness of the nitride layer is increased from Example 1 to Example 3. The electroluminescence spot measurement brightness of the epitaxial wafer is increased from 132 to 256 in Example 1, and the spot measurement voltage is reduced from 4.5V to 3.2V, so it can be controlled in combination with practical applications. The annealing and recrystallization of the TMG source mixed precursor coating layer can match the thickness of the unintentionally doped nitride layer and the n-type nitride layer, and meet the different requirements of epitaxial wafer surface defects and photoelectric performance.

The inventors of this case also used different uniformly dispersed metal nanoparticles (such as Au, Ag, Fe, Co, Mn, Ti, Mg, Al, Ga, In, etc.) TMG source precursor layer as a stress release buffer layer by spin coating. Tests show that as a stress release, it can reduce the dislocation density and residual stress, improve the growth quality of the quantum well light-emitting layer, improve the leakage performance and luminous efficiency, and improve the uniformity of the light-emitting wavelength, which can meet the uniform performance requirements for Micro-LED epitaxy.

Example 4

1) Preparation of Si ₃ N ₄ nanoparticle dispersion

Using absolute ethanol, add 10% by mass fraction of Si ₃ N ₄ nanopowder with a diameter of 30-80 nm, add 0.15% by mass fraction of citric acid dispersant, and sonicate for 30 minutes at room temperature;

2) Preparation of Si ₃ N ₄ nanoparticle TMG source

Separate the Si ₃ N ₄ nanoparticles from the solvent, quickly dry them, and immediately mix them with a high-purity TMG source. The mass fraction of Si ₃ N ₄ nanoparticles is 10%, and ultrasonicate at 25°C for 30 minutes to obtain TMG with uniformly dispersed Si ₃ N ₄ nanoparticles. source mixed precursor;

3) Spin coating Si ₃ N ₄ nanoparticles TMG source mixed precursor

In the _N2 atmosphere of the glove box, the Si ₃ N ₄ nanoparticle TMG source mixed precursor was spin-coated on the sapphire substrate at a speed of 4000 rpm by the spin coating method of the homogenizer, and a uniformly dispersed Si with a thickness of 80 nm was formed on the substrate. TMG source mixed precursor coating layer of ₃ N ₄ nanoparticles;

4) Growth of LED epitaxial wafers on MO source coating layer

①Place the sapphire substrate with the TMG source mixed precursor coating layer of dispersed Si ₃ N ₄ nanoparticles in the MOCVD reaction chamber, set the pressure at 300torr, feed the TMG source, set the temperature rise to 1200°C, and feed NH ₃ and H ₂ were annealed and recrystallized for 15s, and the flow ratio of NH ₃ and H ₂ was 80:1 to prepare GaN stress relief buffer layer 2;

② On the GaN stress release buffer layer 2, under the conditions of temperature of 1080°C and growth pressure of 200torr, an unintentionally doped nitride layer 13 with a thickness of 3 μm is grown, which is an unintentionally doped GaN layer, and the required Ga The source is TMG source, and the growth atmosphere is _H2 atmosphere;

③ On the unintentionally doped nitride layer 13, under the conditions of a temperature of 1060° C. and a growth pressure of 200 torr, grow an n-type nitride layer 14 with a thickness of 3 μm, which is an n-type GaN layer, and the doping concentration of Si is 8×10 ¹⁸ cm ^-3 , the Ga source required for growth is TMG source, and the growth atmosphere is H ₂ atmosphere;

④Grow a light-emitting layer on the n-type nitride layer 14, in order to repeatedly grow 6 pairs of InGaN/GaN multi-quantum well light-emitting layers, the thickness of the InGaN quantum well layer is 3nm, the growth temperature is 770°C, and the growth atmosphere is switched to _N2 atmosphere , the growth pressure is 300torr, the thickness of the GaN quantum barrier layer is 11nm, the growth temperature is 825°C, the growth atmosphere is switched to H ₂ atmosphere, the growth pressure is 300torr, the Ga source required for growth is TEGa, and the In source is TMIn;

⑤On the InGaN/GaN multi-quantum well light-emitting layer, under the conditions of temperature 1000°C and growth pressure 200torr, an electron blocking layer with a thickness of 15nm is grown, which is a p-type AlGaN electron blocking layer, and the Ga The source is TMG source, the Al source is TMAl, and the growth atmosphere is _N2 atmosphere;

⑥ On the electron blocking layer, grow a p-type nitride layer 17 with a thickness of 20nm under the conditions of a temperature of 950°C and a growth pressure of 300torr, which is a p-type GaN layer with a Mg doping concentration of 5×10 ¹⁹ cm ^{- 3.} The Ga source required for growth is TMG source, and the growth atmosphere is switched to H ₂ atmosphere.

The thickness uniformity of the epitaxial layer of the LED epitaxial wafer obtained in this embodiment is less than 2%, the half-maximum width of the 470nm blue light wave in the photoluminescence PL test is 18.7nm, the wavelength uniformity std is 0.85nm, and the leakage IR yield rate of the 0405 chip size test is 98.5%. .

Example 5

1) Preparation of Al ₂ O ₃ nanoparticle dispersion

Using absolute ethanol, add 15% by mass fraction of Al ₂ O ₃ nanopowder with a diameter of 50-200 nm, add 0.15% by mass fraction of citric acid dispersant, and sonicate for 30 minutes at room temperature;

2) Preparation of Al ₂ O ₃ nanoparticles TMG source

Separate the Al ₂ O ₃ nanoparticles from the solvent, quickly dry them, and immediately mix them with a high-purity TMG source. The mass fraction of Al ₂ O ₃ nanoparticles is 15%, and ultrasonicate at 15°C for 60 minutes to obtain TMG with evenly dispersed Al ₂ O ₃ nanoparticles source mixed precursor;

3) Spin coating Al ₂ O ₃ nanoparticles TMG source mixed precursor

In the _N2 atmosphere of the glove box, the _Al2O3 nanoparticle TMG source mixed precursor was spin _- coated on the sapphire substrate at a speed of 2000rpm by the spin coating method of the homogenizer, and a uniformly dispersed Al with a thickness of 80nm was formed on the substrate. TMG source mixed precursor coating layer of ₂ O ₃ nanoparticles;

4) Growth of LED epitaxial wafers on MO source coating layer

①Place the sapphire substrate with the TMG source mixed precursor coating layer of dispersed Al ₂ O ₃ nanoparticles in the MOCVD reaction chamber, set the pressure to 200torr, feed the TMG source, set the temperature rise to 1200°C, and feed NH ₃ and H ₂ were annealed and recrystallized for 30s, and the flow ratio of NH ₃ and H ₂ was 100:1 to prepare GaN stress relief buffer layer 2;

④ On the n-type nitride layer 14, grow a light-emitting layer, in order to repeatedly grow 6 pairs of InGaN/GaN multi-quantum well light-emitting layers, the thickness of the InGaN quantum well layer is 3nm, the growth temperature is 730°C, and the growth atmosphere is switched to _N2 atmosphere , the growth pressure is 400torr, the thickness of the GaN quantum barrier layer is 11nm, the growth temperature is 805°C, the growth atmosphere is switched to H ₂ atmosphere, the growth pressure is 400torr, the Ga source required for growth is TEGa, and the In source is TMIn;

⑤On the InGaN/GaN multi-quantum well light-emitting layer, under the condition of temperature of 1050°C and growth pressure of 100torr, an electron blocking layer with a thickness of 150nm is grown, which is a p-type AlGaN electron blocking layer, and the Ga The source is TMG source, the Al source is TMAl, and the growth atmosphere is _N2 atmosphere;

⑥On the electron blocking layer, grow a p-type nitride layer 17 with a thickness of 200nm under the conditions of a temperature of 1050°C and a growth pressure of 200torr, which is a p-type GaN layer with a Mg doping concentration of 5×10 ¹⁹ cm ^{- 3.} The Ga source required for growth is TMG source, and the growth atmosphere is switched to H ₂ atmosphere.

After testing, the photoluminescence PL test of the LED epitaxial wafer obtained in this example has a 470nm blue light half-maximum width of 18.5nm, a wavelength uniformity std of 0.98nm, and a surface defect of 2×10 ⁸ cm ^-2 . The nanoparticle TMG source precursor layer is used as a stress release buffer layer. As a stress release, it can reduce the dislocation density and residual stress, improve the growth quality of the quantum well light-emitting layer, improve the leakage performance and luminous efficiency, and improve the uniformity of the light-emitting wavelength, which can meet It is suitable for Micro-LED epitaxial uniform performance requirements.

Example 6

1) Preparation of graphene dispersion

Using absolute ethanol, add graphene nanopowder with a mass fraction of 5% and a diameter of 300-500nm, add a citric acid dispersant with a mass fraction of 0.15%, and sonicate at room temperature for 30 minutes;

2) Preparation of graphene nanoparticle TMG source

The graphene nanoparticles are separated from the solvent, quickly dried and immediately mixed with a high-purity TMG source. The mass fraction of the graphene nanoparticles is 5%, and ultrasonicated at 25°C for 45 minutes to obtain a TMG source mixed precursor with uniformly dispersed graphene nanoparticles;

3) Spin-coating graphene nanoparticles TMG source mixed precursor

In the _N2 atmosphere of the glove box, the graphene nanoparticle TMG source mixed precursor was spin-coated on the sapphire substrate at a speed of 4000rpm by the spin-coating method of the homogenizer, and a uniformly dispersed graphene nanoparticle with a thickness of 2000nm was formed on the substrate. TMG source mixed precursor coating layer of particles;

4) Growth of LED epitaxial wafers on MO source coating layer

① Place the sapphire substrate with the TMG source mixed precursor coating layer of dispersed graphene nanoparticles in the MOCVD reaction chamber, set the pressure at 100torr, feed the TMG source, set the temperature rise to 1200°C, and feed NH ₃ Annealing and recrystallizing with H ₂ for 100s, the flow ratio of NH ₃ and H ₂ is 50:1, and the GaN stress relief buffer layer 2 is prepared;

④ On the n-type nitride layer 14, grow a light-emitting layer, in order to repeatedly grow 10 pairs of InGaN/GaN multi-quantum well light-emitting layers, the thickness of the InGaN quantum well layer is 6nm, the growth temperature is 800°C, and the growth atmosphere is switched to _N2 atmosphere , the growth pressure is 200torr, the thickness of the GaN quantum barrier layer is 6nm, the growth temperature is 900°C, the growth atmosphere is switched to H ₂ atmosphere, the growth pressure is 200torr, the Ga source required for growth is TEGa, and the In source is TMIn;

⑥ On the electron blocking layer, grow a p-type nitride layer 17 with a thickness of 50 nm under the conditions of a temperature of 950°C and a growth pressure of 600 torr, which is a p-type GaN layer with a Mg doping concentration of 5×10 ¹⁹ cm ^{- 3.} The Ga source required for growth is TMG source, and the growth atmosphere is switched to H ₂ atmosphere.

Example 7

1) Preparation of _TiO2 nanoparticle dispersion

Using absolute ethanol, add 30% _TiO2 nano powder with a diameter of 30-80nm in mass fraction, add citric acid dispersant with a mass fraction of 0.15%, and sonicate for 2 hours at room temperature;

2) Preparation of _TiO2 nanoparticles TMG source

The TiO ₂ nanoparticles were separated from the solvent, quickly dried and immediately mixed with a high-purity TMG source. The mass fraction of the TiO ₂ nanoparticles was 28%, and ultrasonicated at 5°C for 50 minutes to obtain a TMG source mixed precursor with uniformly dispersed TiO ₂ nanoparticles;

3) Spin coating _TiO2 nanoparticles TMG source mixed precursor

In the _N2 atmosphere of the glove box, the _TiO2 nanoparticle TMG source mixed precursor was spin-coated on the sapphire substrate at a speed of 4000rpm by the spin coating method of the homogenizer, and a uniformly dispersed _TiO2nm layer with a thickness of 2000nm was formed on the substrate. TMG source mixed precursor coating layer of particles;

4) Growth of LED epitaxial wafers on MO source coating layer

① Place the sapphire substrate with TMG source mixed precursor coating layer dispersed TiO ₂ nanoparticles in the MOCVD reaction chamber, set the pressure at 600torr, feed the TMG source, set the temperature rise to 1200°C, and feed NH ₃ Annealing and recrystallizing with H ₂ for 100s, the flow ratio of NH ₃ and H ₂ is 30:1, and the GaN stress relief buffer layer 2 is prepared;

All the other steps are the same as in Example 6.

Example 5 and Example 6 respectively prepared ultraviolet light epitaxial wafers with wavelengths of 400nm and 415nm, and the photoluminescence PL test wavelength uniformity std of LED epitaxial wafers was 0.52 and 0.65nm, the half-maximum width was less than 15nm, and the surface defects were 2.2×10 ⁸ cm ^-2 , and the surface roughness Ra of epitaxial wafers is less than 0.7.

The inventors of this case also used different uniformly dispersed metal oxide nanoparticles (such as ZnO, Fe ₃ O ₄ , Ta ₂ O ₅ , SnO ₂ , ZrO _{2 ,} etc.) TMG source precursor layers as stress release buffer layers, as Stress release can reduce dislocation density and residual stress, improve the growth quality of quantum well light-emitting layer, improve leakage performance and luminous efficiency, and improve the uniformity of light-emitting wavelength, which can meet the uniform performance requirements for Micro-LED epitaxy.

Example 8

1) Preparation of GaN nanoparticle dispersion

Using absolute ethanol, add GaN nanopowder with a mass fraction of 30% and a diameter of 30-80nm, add a citric acid dispersant with a mass fraction of 0.15%, and sonicate at room temperature for 2 hours;

2) Preparation of GaN nanoparticles TMG source

GaN nanoparticles are separated from the solvent, quickly dried and immediately mixed with a high-purity TMG source. The mass fraction of GaN nanoparticles is 24%, and ultrasonicated at 5°C for 50 minutes to obtain a TMG source mixed precursor with uniformly dispersed GaN nanoparticles;

3) Spin coating GaN nanoparticles TMG source mixed precursor

In the _N2 atmosphere of the glove box, the GaN nanoparticle TMG source mixed precursor was spin-coated on the sapphire substrate at a speed of 4000 rpm by the spin coating method of the homogenizer, and a uniformly dispersed GaN nanoparticle with a thickness of 2000 nm was formed on the substrate. TMG source mixed precursor coating layer;

4) Growth of LED epitaxial wafers on MO source coating layer

①Place the sapphire substrate with the TMG source mixed precursor coating layer dispersed GaN nanoparticles in the MOCVD reaction chamber, set the pressure at 300torr, feed the TMG source, set the temperature rise to 1200°C, and feed NH ₃ and H ₂ annealing and recrystallization for 100s, the flow ratio of NH ₃ and H ₂ is 60:1, and the GaN stress relief buffer layer 2 is prepared;

All the other steps are the same as in Example 6.

Example 9

1) Preparation of Si dispersion

Using absolute ethanol, add Si nano powder with a mass fraction of 5% and a diameter of 5000-800nm, add a citric acid dispersant with a mass fraction of 0.15%, and sonicate at room temperature for 30 minutes;

2) Preparation of Si nanoparticles TMG source

The Si nanoparticles are separated from the solvent, quickly dried and immediately mixed with a high-purity TMG source, the mass fraction of the Si nanoparticles is 5%, and ultrasonicated at 25°C for 10 minutes to obtain a TMG source mixed precursor with uniformly dispersed Si nanoparticles;

3) Spin-coating Si nanoparticles TMG source mixed precursor

In the _N2 atmosphere of the glove box, the Si nanoparticle TMG source mixed precursor was spin-coated on the sapphire substrate at a speed of 4000 rpm by the spin coating method of the homogenizer, and a uniformly dispersed Si nanoparticle with a thickness of 2000 nm was formed on the substrate. TMG source mixed precursor coating layer;

4) Growth of LED epitaxial wafers on MO source coating layer

①Place the sapphire substrate with the TMG source mixed precursor coating layer of dispersed Si nanoparticles in the MOCVD reaction chamber, set the pressure at 500torr, feed the TMG source, set the temperature rise to 1125°C, and feed NH ₃ and H ₂ annealing and recrystallization for 10s, the flow ratio of NH ₃ and H ₂ is 100:1, and the GaN stress relief buffer layer 2 is prepared;

All the other steps are the same as in Example 6.

The inventors of this case also used different uniformly dispersed non-metallic nanoparticles (such as C, SiC, B ₄ C, BN, etc.) TMG source precursor layer as a stress release buffer layer by spin coating, as a stress release can reduce the dislocation density and residual Stress, improve the growth quality of the quantum well light-emitting layer, improve the leakage performance and luminous efficiency, and at the same time improve the uniformity of the luminous wavelength (std<1nm), the particle on the surface of the epitaxial wafer is less than 10, and the defect density is less than 5×10 ⁸ cm ^-2 , which can meet It is suitable for Micro-LED epitaxial uniform performance requirements.

Correspondingly, the inventors of this case also used uniformly dispersed organic compound nanoparticles, such as the TMG source precursor layer of polystyrene as a buffer layer, and the test results were basically consistent with the foregoing examples.

Example 10

1) Preparation of Ni nanoparticle dispersion

2) Preparation of Ni nanoparticles TMG source

The Ni nanoparticles are separated from the solvent, quickly dried and immediately mixed with a high-purity TMG source. The mass fraction of the Ni nanoparticles is 40%, and ultrasonicated at 40°C for 30 minutes to obtain a TMG source mixed precursor with uniformly dispersed Ni nanoparticles;

3) Spin coating Ni nanoparticles TMG source mixed precursor

In the glove box _N2 atmosphere, the Ni nanoparticle TMG source mixed precursor was spin-coated on the silicon substrate at a speed of 4000rpm by the spin coating method of the homogenizer, and uniformly dispersed Ni nanoparticles with a thickness of 25nm were formed on the substrate. TMG source mixed precursor coating layer;

4) Growth of LED epitaxial wafers on Group III metal-organic source coating layer

① Place the silicon substrate coated with the TMG source mixed precursor coating layer of dispersed Ni nanoparticles in the MOCVD reaction chamber, set the pressure at 200 torr, feed the TMG source, set the temperature rise to 650 °C, and feed AsH ₃ and H ₂ annealing and recrystallization for 10s, the flow ratio of AsH ₃ and H ₂ is 15:1, and the GaAs stress relief buffer layer 2 is prepared;

② On the GaAs stress release buffer layer 2, under the conditions of temperature of 1200°C and growth pressure of 100torr, an unintentionally doped nitride layer 13 with a thickness of 3 μm is grown, which is an unintentionally doped GaN layer, and the required Ga The source is TMG source, and the growth atmosphere is _H2 atmosphere;

③ On the unintentionally doped nitride layer 13, under the conditions of a temperature of 1000° C. and a growth pressure of 600 torr, grow an n-type nitride layer 14 with a thickness of 3 μm, which is an n-type GaN layer, and the doping concentration of Si is 8×10 ¹⁸ cm ^-3 , the Ga source required for growth is TMG source, and the growth atmosphere is H ₂ atmosphere;

④Grow a light-emitting layer on the n-type nitride layer 14, in order to repeatedly grow 6 pairs of InGaN/GaN multi-quantum well light-emitting layers, the thickness of the InGaN quantum well layer is 3nm, the growth temperature is 750°C, and the growth atmosphere is switched to _N2 atmosphere , the growth pressure is 500torr, the thickness of the GaN quantum barrier layer is 11nm, the growth temperature is 810°C, the growth atmosphere is switched to H ₂ atmosphere, the growth pressure is 500torr, the Ga source required for growth is TEGa, and the In source is TMIn;

⑤On the InGaN/GaN multi-quantum well light-emitting layer, under the condition of temperature of 850°C and growth pressure of 200torr, an electron blocking layer with a thickness of 25nm is grown, which is a p-type AlGaN electron blocking layer, and the Ga The source is TMG source, the Al source is TMAl, and the growth atmosphere is _N2 atmosphere;

Example 11

1) Preparation of Ni nanoparticle dispersion

2) Preparation of Ni nanoparticles dimethyl ethyl indium

The Ni nanoparticles are separated from the solvent, quickly dried and immediately mixed with a high-purity dimethyl ethyl indium source. The mass fraction of Ni nanoparticles is 40%, and ultrasonically 30min at 40°C to obtain dimethyl ethyl indium with uniformly dispersed Ni nanoparticles. Indium-based source mixed precursor;

3) Spin-coating Ni nanoparticles trimethyl indium source mixed precursor

In the _N2 atmosphere of the glove box, the Ni nanoparticle dimethyl ethyl indium source mixed precursor was spin-coated on the silicon substrate at a speed of 4000rpm by the spin coating method of the homogenizer, and a uniform layer with a thickness of 20nm was formed on the substrate. Dimethylethylindium source mixed precursor coating layer dispersed Ni nanoparticles;

① Place the gallium arsenide substrate coated with the mixed precursor coating layer of dimethyl ethyl indium source with dispersed Ni nanoparticles in the MOCVD reaction chamber, set the pressure to 400torr, set the temperature rise to 500℃, and pass through the Butyl arsenic (TBA) and H ₂ were annealed and recrystallized for 10 s, the flow ratio of TBA and H ₂ was 15:1, and dimethyl ethyl indium was introduced to prepare the InAs stress release buffer layer 2;

② On the InAs stress release buffer layer 2, under the condition of temperature of 1000°C and growth pressure of 600torr, an unintentionally doped nitride layer 13 with a thickness of 3 μm is grown, which is an unintentionally doped GaN layer, and the required Ga The source is TMG source, and the growth atmosphere is _H2 atmosphere;

③ On the unintentionally doped nitride layer 13, under the conditions of a temperature of 1200° C. and a growth pressure of 100 torr, grow an n-type nitride layer 14 with a thickness of 3 μm, which is an n-type GaN layer, and the doping concentration of Si is 8×10 ¹⁸ cm ^-3 , the Ga source required for growth is TMG source, and the growth atmosphere is H ₂ atmosphere;

④Grow a light-emitting layer on the n-type nitride layer 14, in order to repeatedly grow 6 pairs of InGaN/GaN multi-quantum well light-emitting layers, the thickness of the InGaN quantum well layer is 2nm, the growth temperature is 700°C, and the growth atmosphere is switched to _N2 atmosphere , the growth pressure is 200torr, the thickness of the GaN quantum barrier layer is 20nm, the growth temperature is 950°C, the growth atmosphere is switched to _H2 atmosphere, the growth pressure is 200torr, the Ga source required for growth is TEGa, and the In source is TMIn;

Example 12

1) Preparation of Ni nanoparticle dispersion

2) Preparation of Ni nanoparticles dimethyl ethyl indium

The Ni nanoparticles are separated from the solvent, quickly dried and immediately mixed with high-purity dimethyl ethyl indium, the mass fraction of Ni nanoparticles is 40%, and ultrasonicated at 20°C for 30 minutes to obtain dimethyl ethyl indium with uniformly dispersed Ni nanoparticles. Indium source mixed precursor;

3) Spin-coating Ni nanoparticles with dimethylethylindium mixed precursor

In the _N2 atmosphere of the glove box, the Ni nanoparticle dimethyl ethyl indium source mixed precursor was spin-coated on the silicon substrate at a speed of 4000 rpm by the spin coating method of the homogenizer, and a uniform layer with a thickness of 100 nm was formed on the substrate. Dimethylethylindium source mixed precursor coating layer dispersed Ni nanoparticles;

① Place the gallium arsenide substrate with the dimethyl ethyl indium source mixed precursor coating layer dispersed with Ni nanoparticles in the MOCVD reaction chamber, set the pressure at 500torr, feed dimethyl ethyl indium, and raise the temperature Set at 650°C, pass through tert-butylphosphine (TBP) and H ₂ for annealing and recrystallization for 100 s, and the flow ratio of TBP and H ₂ is 20:1 to prepare InP stress relief buffer layer 2;

All the other steps are the same as in Example 11.

The above Example 10, Example 11 and Example 12 prepared nitride LED epitaxial layers respectively on GaAs substrates by spin-coating different uniformly dispersed metal nanoparticle source mixed precursor layers as stress release buffer layers, because Gallium arsenide substrate has high quality, easy cleavage and low price, and mature technology, which expands the practicability of GaAs substrate nitride materials, and gallium arsenide is easy to p-type doping to improve light extraction efficiency. Compared with gallium arsenide substrate For the nitride LED prepared by the conventional buffer layer method, the intensity of the epitaxial PL test is increased by more than 10 times, and the intensity of the spot measurement electroluminescence under the condition of 20mA is increased by more than 6 times.

Example 13

1) Preparation of Ni nanoparticle dispersion

2) Preparation of Ni nanoparticles trimethylaluminum source

The Ni nanoparticles are separated from the solvent, quickly dried and immediately mixed with a high-purity trimethylaluminum source, the mass fraction of Ni nanoparticles is 45%, and ultrasonicated at 40°C for 40 minutes to obtain a trimethylaluminum source mixture with uniformly dispersed Ni nanoparticles Precursor;

3) Spin-coating Ni nanoparticles trimethylaluminum source mixed precursor

In the _N2 atmosphere of the glove box, the Ni nanoparticle trimethylaluminum source mixed precursor was spin-coated on the sapphire substrate at a speed of 4000 rpm by the spin coating method of the homogenizer, and a uniformly dispersed Ni with a thickness of 60 nm was formed on the substrate. Trimethylaluminum source mixed precursor coating layer of nanoparticles;

① Place the sapphire substrate with the mixed precursor coating layer of trimethylaluminum source dispersed Ni nanoparticles in the MOCVD reaction chamber, set the pressure at 100torr, feed the trimethylaluminum source, and set the temperature rise to 1200°C , pass through NH ₃ and H ₂ for annealing and recrystallization for 10s, the flow ratio of NH ₃ and H ₂ is 50:1, and make AlN stress release buffer layer 2;

All the other steps are the same as in Example 11.

Comparative example 1

The difference between this comparative example and Example 1 is that no Ni nanoparticles are added to the TMG source.

The surface roughness Ra of the epitaxial wafer obtained in this comparative example is 0.8, and the thickness uniformity of the epitaxial layer is 2.5%. The half-maximum width of the 470nm blue light wave of the photoluminescence PL test is 20nm, and the wavelength uniformity std is 1.5nm. The surface defect of the epitaxial wafer is 7×10 ⁸ cm ^-2 , the luminance of electroluminescent spot measurement is 125, and the spot measurement voltage is 5.2V.

Comparative example 2

The difference between this comparative example and Example 1 is that the GaN buffer layer is directly grown by conventional MOCVD epitaxy instead of spin-coating with TMG source.

The surface roughness Ra of the epitaxial wafer obtained in this comparative example is 1, the thickness uniformity of the epitaxial layer is 3%, the half-maximum width of the 470nm blue light wave of the photoluminescence PL test is 22nm, the wavelength uniformity std is 2nm, and the surface defect of the epitaxial wafer is 8×10 ⁸ cm ^-2 , the luminance of electroluminescent spot measurement is 118, and the spot measurement voltage is 5.9V.

Example 1 of the present application, comparative example 1 and comparative example 2 finally produced LED chips of the same size and found that the brightness of the embodiment 1 of the present application was increased by more than 2% compared with the comparative example 1, and the leakage IR yield was increased by 4%. The results are shown in Table 1 .

Table 1

Therefore, this application spin-coats different uniformly dispersed metal nanoparticle coating layers, and at the same time combines MOCVD reaction chamber annealing and recrystallization, and the metal-organic source coating layer dispersed by nanomaterials gradually forms two types of crystal nuclei distributions to provide nucleation centers, epitaxy The layer stress is gradually released, the lateral epitaxial growth is strengthened, the dislocation density extension of the epitaxial layer is suppressed, the defect density is reduced, the growth quality of the quantum well light-emitting layer is improved, the leakage performance and luminous efficiency are improved, and the uniformity of the light-emitting wavelength is improved at the same time, which can meet the requirements of Micro - LED epitaxial uniform performance requirements.

Example 14

1) Preparation of Ni nanoparticle dispersion

Using absolute ethanol, add 10% by mass fraction of nano-Ni powder with a diameter of 30 to 80 nm, add 0.15% by mass fraction of citric acid dispersant, and sonicate for 30 minutes at room temperature;

2) Preparation of Ni nanoparticles TMG source

The Ni nanoparticles were separated from the solvent, quickly dried and immediately mixed with a high-purity TMG source. The mass fraction of Ni nanoparticles was 10%, and ultrasonicated at 40°C for 60 minutes to obtain a TMG source mixed precursor with uniformly dispersed Ni nanoparticles;

3) Epitaxial growth of unintentionally doped GaN layer

① Put the sapphire substrate on the carrier plate in the MOCVD reaction chamber, and clean the substrate surface for 1 min in the _H2 atmosphere at a temperature of 1100 °C;

②Grow a GaN buffer layer with a thickness of 25nm on a sapphire substrate at a temperature of 540°C and a growth pressure of 300torr. The Ga source required for growth is a TMG source, and the growth atmosphere is an _H2 atmosphere;

③Grow an unintentionally doped GaN layer with a thickness of 3 μm on the GaN buffer layer at a temperature of 1080°C and a growth pressure of 200 torr. The required Ga source is a TMG source, and the growth atmosphere is an _H2 atmosphere;

4) Spin coating Ni nanoparticles TMG source mixed precursor

In the _N2 atmosphere of the glove box, the mixed precursor of the Ni nanoparticle TMG source was spin-coated on the unintentionally doped GaN layer at a speed of 4000rpm by using a homogenizer spin coating method to form a uniform dispersion on the unintentionally doped GaN layer. The TMG source mixed precursor coating layer of Ni nanoparticles; then placed in the MOCVD reaction chamber, the pressure is set to 300torr, the TMG source is fed, the temperature rise is set to 1200°C, and NH ₃ and H ₂ are fed for annealing and recrystallization for 10s , the flow ratio of NH ₃ and H ₂ is 100:1, and a metal-organic source insertion layer with a thickness of 100 nm is formed on the unintentionally doped GaN layer;

5) On the metal-organic insertion layer, grow an n-type GaN layer with a thickness of 3 μm under the conditions of a temperature of 1060°C and a growth pressure of 200 torr. The doping concentration of Si is 8×10 ¹⁸ cm ^-3 . Ga source is TMG source, growth atmosphere is _H2 atmosphere;

6) On the n-type GaN layer, grow an InGaN/GaN multi-quantum well light-emitting layer under the condition of a growth pressure of 250 torr, which is an InGaN quantum well layer and a GaN quantum barrier layer that are periodically and alternately grown, and the repeat period of the light-emitting layer is 9. The thickness of the InGaN quantum well layer is 3nm, the growth temperature is 750°C, the thickness of the GaN quantum barrier layer is 12nm, and the growth temperature is 810°C;

7) On the InGaN/GaN multi-quantum well light-emitting layer, grow a p-type AlGaN electron blocking layer with a thickness of 25nm at a temperature of 850°C and a growth pressure of 200torr. The Ga source required for growth is a TMG source , the Al source is TMAl, and the growth atmosphere is _N2 atmosphere;

8) On the p-type AlGaN electron blocking layer, grow a p-type GaN layer with a thickness of 50nm at a temperature of 930°C and a growth pressure of 200torr, with a Mg doping concentration of 5×10 ¹⁹ cm ^-3 . The required Ga source is TMG source, and the growth atmosphere is switched to H ₂ atmosphere.

The inventors of the present case also coated different uniformly dispersed metal nanoparticles (such as Au, Ag, Fe, Co, Mn, Ti, Mg, Al, Ga, In, etc.) TMG source precursor layer on the unintentionally doped GaN layer. Above, the results are basically the same as in Example 14, the surface dislocation density of the epitaxial wafer is controlled below 5×10 ⁸ cm ^-2 , and the surface roughness Ra of the epitaxial wafer is less than 0.5nm.

Example 15

1) Preparation of Si ₃ N ₄ nanoparticle dispersion

Using absolute ethanol, add 10% Si ₃ N ₄ nanopowder with a diameter of 30-80 nm in mass fraction, add citric acid dispersant with 0.15% mass fraction, and sonicate for 40 minutes at room temperature;

2) Preparation of Si ₃ N ₄ nanoparticle TMG source

The Si ₃ N ₄ nanoparticles were separated from the solvent, quickly dried and immediately mixed with a high-purity TMG source, the mass fraction of Si ₃ N ₄ nanoparticles was 10%, and ultrasonicated at 25°C for 30 minutes to obtain uniformly dispersed Si ₃ N ₄ nanoparticles TMG source mixed precursor;

3) Epitaxial growth of unintentionally doped GaN layer

4) Spin coating Si ₃ N ₄ nanoparticles TMG source mixed precursor

In the _N2 atmosphere of the glove box, the Si ₃ N ₄ nanoparticle TMG source mixed precursor was spin-coated on the unintentionally doped GaN layer at a speed of 4000 rpm by using the spin coating method of a homogenizer, and on the unintentionally doped GaN layer. Form a TMG source mixed precursor coating layer uniformly dispersing Si ₃ N ₄ nanoparticles; then place it in the MOCVD reaction chamber, set the pressure to 300torr, feed the TMG source, set the temperature rise to 1200°C, and feed NH ₃ and H ₂ annealing and recrystallization for 50 s, the flow ratio of NH ₃ and H ₂ is 40:1, and a metal-organic source insertion layer with a thickness of 60 nm is formed on the unintentionally doped GaN layer;

The inventors of this case also spin-coated different uniformly dispersed inorganic nanoparticles (such as SiO ₂ , TiN, BN, AlN, InN, ScAlN, etc.) basically the same.

Example 16

1) Preparation of Al ₂ O ₃ nanoparticle dispersion

Using absolute ethanol, add 10% of Al ₂ O ₃ nano powder with a diameter of 30-80 nm in mass fraction, add 0.15% of citric acid dispersant, and ultrasonicate for 30 minutes at room temperature;

2) Preparation of Al ₂ O ₃ nanoparticles TMG source

Separate Al ₂ O ₃ nanoparticles from the solvent, quickly dry and immediately mix with high-purity TMG source, the mass fraction of Al ₂ O ₃ nanoparticles is 15%, and ultrasonically 60min at 15°C to obtain uniform dispersion of Al ₂ O ₃ nanoparticles TMG source mixed precursor;

3) Epitaxial growth of unintentionally doped GaN layer

4) Spin coating Al ₂ O ₃ nanoparticles TMG source mixed precursor

In the _N2 atmosphere of the glove box, the _Al2O3 nanoparticle TMG source mixed precursor was spin-coated on the unintentionally doped GaN layer at a speed of _4000rpm by using a homogenizer spin coating method, and on the unintentionally doped GaN layer. Form a TMG source mixed precursor coating layer with evenly dispersed Al ₂ O ₃ nanoparticles; then place it in the MOCVD reaction chamber, set the pressure to 300torr, feed the TMG source, set the temperature rise to 1200°C, and feed NH ₃ and H ₂ annealed and recrystallized for 100s, the flow ratio of NH ₃ and H ₂ was 10:1, and a metal-organic source insertion layer with a thickness of 10 nm was formed on the unintentionally doped GaN layer;

6) On the n-type GaN layer, grow an InGaN/GaN multi-quantum well light-emitting layer under the condition of a growth pressure of 250 torr, which is an InGaN quantum well layer and a GaN quantum barrier layer that are periodically and alternately grown, and the repeat period of the light-emitting layer is 9. The thickness of the InGaN quantum well layer is 3nm, the growth temperature is 760°C, the thickness of the GaN quantum barrier layer is 12nm, and the growth temperature is 810°C;

The inventors of the present case also spin-coated different uniformly dispersed metal oxide nanoparticles (such as ZnO, Fe ₃ O ₄ , Ta ₂ O ₅ , SnO ₂ , ZrO _{2 ,} etc.) TMG source precursor layers on unintentionally doped GaN layers. Above, the result is basically the same as in Example 16.

Example 17

1) Preparation of graphene dispersion

2) Preparation of graphene nanoparticle TMG source

3) Epitaxial growth of unintentionally doped GaN layer

4) Spin-coating graphene nanoparticles TMG source mixed precursor

In the _N2 atmosphere of the glove box, the graphene nanoparticle TMG source mixed precursor was spin-coated on the unintentionally doped GaN layer at a speed of 4000rpm by means of a homogenizer spin coating method to form a uniform The TMG source mixed precursor coating layer of dispersed graphene nanoparticles; then placed in the MOCVD reaction chamber, the pressure is set to 300torr, the TMG source is fed, the temperature rise is set to 1200°C, and NH ₃ and H ₂ are fed into the annealing heavy Crystallization for 100s, the flow ratio of _NH3 and _H2 is 20:1, and a metal-organic source insertion layer with a thickness of 10nm is formed on the unintentionally doped GaN layer;

Example 18

1) Preparation of GaN nanoparticle dispersion

Using absolute ethanol, add GaN nanopowder with a mass fraction of 30% to 80nm in diameter, add a citric acid dispersant with a mass fraction of 0.15%, and sonicate at room temperature for 2 hours;

2) Preparation of GaN nanoparticles TMG source

3) Epitaxial growth of unintentionally doped GaN layer

① Put the silicon carbide substrate on the carrier plate in the MOCVD reaction chamber, and clean the substrate surface for 1 min in the _H2 atmosphere at a temperature of 1100 °C;

②Grow a GaN buffer layer with a thickness of 25nm on a silicon carbide substrate at a temperature of 540°C and a growth pressure of 300torr. The Ga source required for growth is a TMG source, and the growth atmosphere is an _H2 atmosphere;

4) Spin coating GaN nanoparticles TMG source mixed precursor

In the _N2 atmosphere of the glove box, the mixed precursor of the GaN nanoparticle TMG source was spin-coated on the unintentionally doped GaN layer at a speed of 3000rpm by the spin-coating method of a homogenizer, and a uniform dispersion was formed on the unintentionally doped GaN layer. The TMG source mixed precursor coating layer of GaN nanoparticles; then placed in the MOCVD reaction chamber, the pressure is set to 400torr, the TMG source is fed, the temperature rise is set to 1000°C, and NH ₃ and H ₂ are fed for annealing and recrystallization for 80s , the flow ratio of NH ₃ and H ₂ was 30:1, and a metal-organic source insertion layer with a thickness of 20 nm was formed on the unintentionally doped GaN layer.

5) On the metal-organic insertion layer, grow an n-type GaN layer with a thickness of 2 μm under the conditions of a temperature of 1040°C and a growth pressure of 150 torr. The doping concentration of Si is 2×10 ¹⁸ cm ^-3 . Ga source is TMG source, growth atmosphere is _H2 atmosphere;

6) On the n-type GaN layer, grow an InGaN/GaN multi-quantum well light-emitting layer under the condition that the growth pressure is 300 torr, which is an InGaN quantum well layer and a GaN quantum barrier layer that are periodically and alternately grown, and the light-emitting layer has a repeat period of 10. The thickness of the InGaN quantum well layer is 6nm, and the growth temperature is 800°C; the thickness of the GaN quantum barrier layer is 20nm, and the growth temperature is 850°C;

7) On the InGaN/GaN multi-quantum well light-emitting layer, grow a p-type AlGaN electron blocking layer with a thickness of 50nm under the conditions of a temperature of 800°C and a growth pressure of 400torr. The Ga source required for growth is a TMG source , the Al source is TMAl, and the growth atmosphere is _N2 atmosphere;

8) On the p-type AlGaN electron blocking layer, grow a p-type GaN layer with a thickness of 20nm at a temperature of 800°C and a growth pressure of 400torr, with a Mg doping concentration of 1×10 ¹⁸ cm ^-3 . The required Ga source is TMG source, and the growth atmosphere is switched to H ₂ atmosphere.

Example 19

1) Preparation of perovskite Ti ₃ SiC ₂ nanoparticle dispersion

Using absolute ethanol, add perovskite Ti ₃ SiC ₂ nanoparticles with a diameter of 30-80nm at a mass fraction of 8%, add a citric acid dispersant with a mass fraction of 0.15%, and sonicate at room temperature for 1.5h;

2) Preparation of perovskite Ti ₃ SiC ₂ nanoparticles TMG source

The perovskite Ti ₃ SiC ₂ nanoparticles were separated from the solvent, quickly dried and immediately mixed with a high-purity TMG source. The mass fraction of the perovskite Ti ₃ SiC ₂ nanoparticles was 18%, and ultrasonicated at 40°C for 20 minutes to obtain uniformly dispersed calcium TMG source mixed precursor of titanite Ti ₃ SiC ₂ nanoparticles;

3) Epitaxial growth of unintentionally doped GaN layer

① Put the silicon substrate on the carrier plate in the MOCVD reaction chamber, and clean the substrate surface for 1 min in the _H2 atmosphere at a temperature of 1100 °C;

②Grow an AlN buffer layer with a thickness of 25nm on a silicon substrate at a temperature of 540°C and a growth pressure of 300torr. The Al source required for growth is a TMAl source, and the growth atmosphere is a _H2 atmosphere;

③Grow an unintentionally doped GaN layer with a thickness of 3 μm on the AlN buffer layer at a temperature of 1080°C and a growth pressure of 200 torr. The required Ga source is a TMG source, and the growth atmosphere is an _H2 atmosphere;

4) Spin-coating perovskite nanoparticles TMG source mixed precursor

In the N ₂ atmosphere of the glove box, the perovskite Ti ₃ SiC ₂ nanoparticle TMG source mixed precursor was spin-coated on the unintentionally doped GaN layer at a speed of 3000 rpm by using a homogenizer spin coating method. On the GaN layer, a TMG source mixed precursor coating layer with uniformly dispersed perovskite Ti ₃ SiC ₂ nanoparticles is formed; then placed in the MOCVD reaction chamber, the pressure is set to 300torr, the TMG source is introduced, and the temperature rise is set to 500°C , pass through NH ₃ and H ₂ for annealing and recrystallization for 100s, the flow ratio of NH ₃ and H ₂ is 50:1, and a metal-organic source insertion layer with a thickness of 30nm is formed on the unintentionally doped GaN layer.

5) On the metal-organic insertion layer, grow an n-type GaN layer with a thickness of 4 μm under the conditions of a temperature of 1070°C and a growth pressure of 100 torr. The doping concentration of Si is 5×10 ¹⁹ cm ^-3 , and the required Ga source is TMG source, growth atmosphere is _H2 atmosphere;

6) On the n-type GaN layer, grow an InGaN/GaN multi-quantum well light-emitting layer under the condition of a growth pressure of 100 torr, which is an InGaN quantum well layer and a GaN quantum barrier layer that are periodically and alternately grown, and the light-emitting layer repeat period is 20. The thickness of the InGaN quantum well layer is 2nm, and the growth temperature is 900°C; the thickness of the GaN quantum barrier layer is 6nm, and the growth temperature is 900°C;

7) On the InGaN/GaN multi-quantum well light-emitting layer, grow a p-type AlGaN electron blocking layer with a thickness of 150nm under the conditions of a temperature of 1000°C and a growth pressure of 100torr. The Ga source required for growth is a TMG source , the Al source is TMAl, and the growth atmosphere is _N2 atmosphere;

8) On the p-type AlGaN electron blocking layer, grow a p-type GaN layer with a thickness of 100nm at a temperature of 1000°C and a growth pressure of 100torr, with a Mg doping concentration of 5×10 ²⁰ cm ^-3 . The required Ga source is TMG source, and the growth atmosphere is switched to H ₂ atmosphere.

Example 20

1) Preparation of polystyrene nanoparticle dispersion

Using absolute ethanol, add polystyrene nanoparticles with a mass fraction of 40% and a diameter of 30-80nm, add a citric acid dispersant with a mass fraction of 0.15%, and sonicate at room temperature for 1.5h;

2) Preparation of polystyrene nanoparticles TMG source

The polystyrene nanoparticles are separated from the solvent, quickly dried and immediately mixed with a high-purity TMG source. The mass fraction of polystyrene nanoparticles is 50%, and ultrasonicated at 40°C for 20 minutes to obtain a uniformly dispersed TMG source of polystyrene nanoparticles. Precursor;

3) Epitaxial growth of unintentionally doped GaN layer

②Grow a GaN buffer layer with a thickness of 25nm on a sapphire substrate at a temperature of 540°C and a growth pressure of 300torr. The Ga source required for the growth is a TMAl source, and the growth atmosphere is a _H2 atmosphere;

4) Spin-coating polystyrene nanoparticles with dimethyl ethyl indium source mixed precursor

In the _N2 atmosphere of the glove box, the polystyrene nanoparticle dimethyl ethyl indium source mixed precursor was spin-coated on the unintentionally doped GaN layer at a speed of 5000 rpm by using the spin coating method of the homogenizer. A dimethyl ethyl indium source mixed precursor coating layer with uniformly dispersed polystyrene nanoparticles is formed on the heterogeneous GaN layer; then placed in the MOCVD reaction chamber, the pressure is set to 200torr, and dimethyl ethyl indium is introduced. Set the temperature rise to 800°C, pass through NH ₃ and H ₂ for annealing and recrystallization for 100 s, the flow ratio of NH ₃ and H ₂ is 60:1, and form a metal-organic source insertion layer with a thickness of 40 nm on the unintentionally doped GaN layer .

Example 21

1) Preparation of Ni nanoparticle dispersion

2) Preparation of Ni nanoparticles TMG source

3) Epitaxial growth of n-type GaN layer

④ On the non-doped nitride layer, under the condition of temperature of 1060℃ and growth pressure of 200torr, grow n-type GaN layer with a thickness of 3μm and Si doping concentration of 8×10 ¹⁸ cm ^-3 . The Ga source is TMG source, and the growth atmosphere is _H2 atmosphere;

4) Spin coating Ni nanoparticles TMG source mixed precursor

In the _N2 atmosphere of the glove box, the mixed precursor of the Ni nanoparticle TMG source was spin-coated on the n-type GaN layer at a speed of 4000 rpm by using the spin-coating method of a homogenizer, and uniformly dispersed Ni nanoparticles were formed on the n-type GaN layer. TMG source mixed with the precursor coating layer; then placed in the MOCVD reaction chamber, the pressure was set to 300torr, the TMG source was fed, the temperature was set to 1200°C, and NH ₃ and H ₂ were fed for annealing and recrystallization for 10s, NH ₃ and The flow ratio of _H2 is 10:1, and a metal-organic source insertion layer 100 with a thickness of 60 nm is formed on the n-type GaN layer;

5) Epitaxial growth of light-emitting layer

①On the metal-organic source insertion layer, grow a quantum barrier modification layer with a thickness of 80nm at a temperature of 920°C and a growth pressure of 150torr, and then grow a quantum barrier modification layer at a temperature of 820°C and a growth pressure of 300torr. An InGaN quantum well layer with a layer thickness of 4nm forms the first light-emitting layer;

②Under the condition of the growth pressure of 200torr, the InGaN/GaN multi-quantum well light-emitting layer is then grown, which is an InGaN quantum well layer and a GaN quantum barrier layer that are periodically and alternately grown. The repetition period of the light-emitting layer is 9, and the InGaN quantum well layer The thickness is 3nm, the growth temperature is 780°C, the thickness of the GaN quantum barrier layer is 12nm, and the growth temperature is 860°C;

6) Epitaxial growth of p-type GaN layer

① On the InGaN/GaN multi-quantum well light-emitting layer, grow a p-type AlGaN electron barrier layer with a thickness of 25nm under the conditions of a temperature of 850°C and a growth pressure of 200torr. The Ga source required for growth is a TMG source. Al source is TMAl, growth atmosphere is _N2 atmosphere;

② On the p-type AlGaN electron blocking layer, grow a p-type GaN layer with a thickness of 50nm at a temperature of 930°C and a growth pressure of 200torr, with a Mg doping concentration of 5×10 ¹⁹ cm ^-3 . The Ga source is TMG source, and the growth atmosphere is switched to _H2 atmosphere.

Example 22

1) Preparation of Ni nanoparticle dispersion

2) Preparation of Ni nanoparticles TMG source

3) Epitaxial growth of n-type GaN layer

4) Spin coating Ni nanoparticles TMG source mixed precursor

In the _N2 atmosphere of the glove box, the mixed precursor of the Ni nanoparticle TMG source was spin-coated on the n-type GaN layer at a speed of 4000 rpm by using the spin-coating method of a homogenizer, and uniformly dispersed Ni nanoparticles were formed on the n-type GaN layer. TMG source mixed with the precursor coating layer; then placed in the MOCVD reaction chamber, the pressure was set to 600torr, the TMG source was fed, the temperature was set to 1000°C, and NH ₃ and H ₂ were fed for annealing and recrystallization for 30s, NH ₃ and The flow ratio of H ₂ is 50:1, and a metal-organic source insertion layer 100 with a thickness of 60 nm is formed on the n-type GaN layer;

5) Epitaxial growth of light-emitting layer

①On the metal-organic source insertion layer, grow a quantum barrier modification layer with a thickness of 50nm and a thickness of 100nm under the conditions of temperature 750°C, growth pressure 350torr and temperature 950°C, growth pressure 150torr respectively, Construct a quantum barrier modification layer, and then grow a layer of InGaN quantum well layer with a thickness of 4nm under the conditions of a temperature of 820°C and a growth pressure of 300torr to form the first light-emitting layer;

②Then grow the InGaN/GaN multi-quantum well light-emitting layer under the condition of a growth pressure of 150 torr, which is an InGaN quantum well layer and a GaN quantum barrier layer that are periodically and alternately grown. The repeat period of the light-emitting layer is 9. The InGaN quantum well layer The thickness is 3nm, the growth temperature is 785°C, the thickness of the GaN quantum barrier layer is 12nm, and the growth temperature is 865°C;

6) Epitaxial growth of p-type GaN layer

In Examples 21 and 22 of the present application, the coating layer is formed by spin-coating the TMG source of dispersed nanoparticles, combined with the quantum barrier modification layer. In Example 21, the quantum barrier modification layer is grown by lateral epitaxy, and the nanostructure of the MO source insertion layer is quickly filled. , Example 22 first adopts the vertical epitaxial growth process to increase the nanostructure size of the MO source insertion layer to form a quantum dot light-emitting layer, which can meet different performance requirements of LEDs.

Example 23

1) Preparation of Al ₂ O ₃ nanoparticle dispersion

Using absolute ethanol, add 15% of Al ₂ O ₃ nano powder with a diameter of 30-80 nm in mass fraction, add 0.15% of citric acid dispersant, and ultrasonicate for 30 minutes at room temperature;

2) Preparation of Al ₂ O ₃ nanoparticles TMG source

3) Epitaxial growth of n-type GaN layer

4) Spin coating SiC nanoparticles TMG source mixed precursor

In the _N2 atmosphere of the glove box, the SiC nanoparticle TMG source mixed precursor was spin-coated on the n-type GaN layer at a speed of 4000 rpm by using the spin-coating method of a homogenizer to form a uniform dispersion of SiC nanoparticles on the n-type GaN layer. TMG source mixed with the precursor coating layer; then placed in the MOCVD reaction chamber, the pressure was set to 300torr, the TMG source was fed, the temperature was set to 1200°C, and NH ₃ and H ₂ were fed for annealing and recrystallization for 80s, NH ₃ and The flow ratio of _H2 was 80:1, and a metal-organic source insertion layer with a thickness of 60nm was formed on the n-type GaN layer.

5) Epitaxial growth of light-emitting layer

① On the metal-organic source insertion layer, grow a quantum barrier modification layer with a thickness of 10nm at a temperature of 900°C and a growth pressure of 50torr, and then grow a quantum barrier modification layer at a temperature of 820°C and a growth pressure of 300torr. An InGaN quantum well layer with a layer thickness of 2nm forms the first light-emitting layer;

6) Epitaxial growth of p-type GaN layer

The inventors of this case also spin-coated different uniformly dispersed inorganic nanoparticles (such as Si, C, TiC, WC, B ₄ C, etc.) TMG source precursor layers on the n-type GaN layer, and the results were basically the same as in Example 21.

Example 24

1) Preparation of WC- _CO nanoparticle dispersion

Using absolute ethanol, add 30% by mass fraction of WC- _CO nanocomposite powder with a diameter of 30 to 80 nm, add 0.15% by mass fraction of citric acid dispersant, and sonicate for 2 hours at room temperature;

2) Preparation of WC- _CO nanoparticles TMG source

The WC- _CO nanoparticles were separated from the solvent, quickly dried and immediately mixed with a high-purity TMG source, the mass fraction of WC- _CO nanoparticles was 40%, and ultrasonicated at 40°C for 60 min to obtain uniformly dispersed WC- _CO nanoparticles. TMG source mixed precursor;

3) Epitaxial growth of n-type GaN layer

4) Spin-coating WC- _CO nanoparticles TMG source mixed precursor

In the _N2 atmosphere of the glove box, the WC- _CO nanoparticle TMG source mixed precursor was spin-coated on the n-type GaN layer at a speed of 4000 rpm by using a homogenizer spin-coating method to form a uniformly dispersed WC on the n-type GaN layer. _-CO nanoparticle TMG source mixed precursor coating layer; then placed in the MOCVD reaction chamber, the pressure is set to 200torr, the TMG source is fed, the temperature rise is set to 1000°C, and NH ₃ and H ₂ are fed into the annealing heavy After crystallization for 60s, the flow ratio of _NH3 and _H2 was 30:1, and a metal-organic source insertion layer with a thickness of 60nm was formed on the n-type GaN layer.

5) Epitaxial growth of light-emitting layer

①On the metal-organic source insertion layer, grow a quantum barrier modification layer with a thickness of 500nm under the conditions of a temperature of 950°C and a growth pressure of 350torr, and then grow a layer of InGaN quantum well layer with a thickness of 6nm to form the first A luminous layer.

6) Epitaxial growth of p-type GaN layer

Example 25

1) Preparation of _MoS2 nanoparticle dispersion

Using absolute ethanol, add MoS ₂ nanocomposite powder with a diameter of 30-80nm at a mass fraction of 35%, add a citric acid dispersant with a mass fraction of 0.15%, and sonicate for 2 hours at room temperature;

2) Preparation of _MoS2 nanoparticles TMG source

The MoS ₂ nanoparticles were separated from the solvent, quickly dried and immediately mixed with a high-purity TMG source. The mass fraction of MoS ₂ nanoparticles was 40%, and ultrasonicated at 40°C for 60 minutes to obtain a TMG source mixed precursor with uniformly dispersed MoS ₂ nanoparticles;

3) Epitaxial growth of n-type GaN layer

① Put the ZnO substrate on the carrier plate in the MOCVD reaction chamber, and clean the substrate surface for 1 min in the _H2 atmosphere at a temperature of 950 °C;

②Grow a GaN buffer layer with a thickness of 25nm on a ZnO substrate at a temperature of 540°C and a growth pressure of 300torr. The Ga source required for growth is a TMG source, and the growth atmosphere is an _H2 atmosphere;

③Grow an unintentionally doped GaN layer with a thickness of 3 μm on the GaN buffer layer at a temperature of 1015°C and a growth pressure of 200 torr. The required Ga source is a TMG source, and the growth atmosphere is an _H2 atmosphere;

④On the non-doped nitride layer, under the condition of temperature of 1025℃ and growth pressure of 200torr, grow n-type GaN layer with a thickness of 3μm, and the doping concentration of Si is 8×10 ¹⁸ cm ^-3 . The Ga source is TMG source, and the growth atmosphere is _H2 atmosphere;

4) Spin-coating MoS ₂ nanoparticles trimethylaluminum source mixed precursor

In the _N2 atmosphere of the glove box, the _MoS2 nanoparticle trimethylaluminum source mixed precursor was spin-coated on the n-type GaN layer at a speed of 4000rpm by the spin-coating method of a homogenizer, and a uniform dispersion was formed on the n-type GaN layer. Trimethylaluminum source mixed precursor coating layer of _MoS2 nanoparticles; then placed in the MOCVD reaction chamber, the pressure is set to 300torr, the TMAl source is fed, the temperature rise is set to 500°C, and NH ₃ and H ₂ are fed Annealing and recrystallization for 80s, the flow ratio of NH ₃ and H ₂ is 80:1, and a metal-organic source insertion layer with a thickness of 30nm is formed on the n-type GaN layer.

5) Epitaxial growth of light-emitting layer

①On the metal-organic source insertion layer, grow a quantum barrier modification layer with a thickness of 20nm and a thickness of 80nm under the conditions of temperature 720°C, growth pressure 350torr and temperature 850°C, growth pressure 150torr, respectively, Construct a quantum barrier modification layer, and then grow a layer of InGaN quantum well layer with a thickness of 6nm under the conditions of a temperature of 760°C and a growth pressure of 300torr to form the first light-emitting layer;

②Under the condition of the growth pressure of 200torr, the InGaN/GaN multi-quantum well light-emitting layer is then grown, which is an InGaN quantum well layer and a GaN quantum barrier layer that are periodically and alternately grown. The repetition period of the light-emitting layer is 9, and the InGaN quantum well layer The thickness is 3nm, the growth temperature is 750°C, the thickness of the GaN quantum barrier layer is 12nm, and the growth temperature is 810°C;

6) Epitaxial growth of p-type GaN layer

Example 26

1) Preparation of Ni nanoparticle dispersion

2) Preparation of Ni nanoparticles TMG source

3) Put the sapphire substrate on the carrier plate in the MOCVD reaction chamber, and perform the substrate surface cleaning treatment in the _H2 atmosphere with a temperature of 1100 ° C for 1 min;

4) On a sapphire substrate, grow a GaN buffer layer with a thickness of 25nm under the conditions of a temperature of 540°C and a growth pressure of 300torr. The Ga source required for growth is a TMG source, and the growth atmosphere is an _H2 atmosphere;

5) On the GaN buffer layer, under the conditions of a temperature of 1080°C and a growth pressure of 200 torr, an unintentionally doped GaN layer with a thickness of 3 μm is grown, the required Ga source is a TMG source, and the growth atmosphere is an _H2 atmosphere;

6) An n-type GaN layer with a thickness of 3 μm was grown on the non-doped nitride layer at a temperature of 1060°C and a growth pressure of 200 torr, and the doping concentration of Si was 8×10 ¹⁸ cm ^-3 . The required Ga source is TMG source, and the growth atmosphere is _H2 atmosphere;

7) On the n-type GaN layer, grow an InGaN/GaN multi-quantum well light-emitting layer under the condition that the growth pressure is 250 torr, which is an InGaN quantum well layer and a GaN quantum barrier layer that are periodically and alternately grown, and the repeat period of the light-emitting layer is 9. The thickness of the InGaN quantum well layer is 3nm, the growth temperature is 750°C, the thickness of the GaN quantum barrier layer is 12nm, and the growth temperature is 815°C;

8) On the InGaN/GaN multi-quantum well light-emitting layer, grow a p-type AlGaN electron blocking layer with a thickness of 25nm at a temperature of 850°C and a growth pressure of 200torr. The Ga source required for growth is a TMG source , the Al source is TMAl, and the growth atmosphere is _N2 atmosphere;

9) On the p-type AlGaN electron blocking layer, grow a p-type GaN front layer with a thickness of 100nm at a temperature of 930°C and a growth pressure of 200torr, with a Mg doping concentration of 5×10 ¹⁹ cm ^-3 , and grow The required Ga source is TMG source, and the growth atmosphere is switched to _H2 atmosphere.

10) In the _N2 atmosphere of the glove box, the Ni nanoparticle TMG source mixed precursor was spin-coated on the p-type GaN front layer by spin-coating method at a speed of 4000rpm, forming a thickness of 20nm TMG source mixed precursor coating layer with uniformly dispersed Ni nanoparticles;

11) Place the epitaxial wafer with the TMG source mixed precursor coating layer in the MOCVD reaction chamber, set the pressure at 100torr, feed the TMG source, set the temperature rise to 800°C, and feed NH ₃ and H ₂ for annealing and recrystallization 50s, the flow ratio of NH ₃ and H ₂ is 20:1, and a MO source insertion layer 100 with a thickness of 100 nm is formed on the p-type GaN front layer;

12) On the epitaxial wafer obtained in step 11), grow a p-type GaN rear layer with a thickness of 20 nm under the conditions of a temperature of 930°C and a growth pressure of 200 torr, with a Mg doping concentration of 1×10 ¹⁹ cm ^-3 , and grow The required Ga source is TMG source, and the growth atmosphere is switched to _H2 atmosphere;

13) Place the epitaxial wafer obtained in step 12) in an O ₂ atmosphere, and anneal at 560° C. for 30 min to obtain an LED epitaxial wafer with a low-ohmic contact p-type GaN layer.

Example 27

Compared with Embodiment 26, this embodiment differs in that the substrate is replaced by a gallium nitride substrate.

12) On the epitaxial wafer obtained in step 11), grow a p-type GaN rear layer with a thickness of 2nm at a temperature of 800°C and a growth pressure of 400torr, with a Mg doping concentration of 1×10 ¹⁸ cm ^-3 , and grow The required Ga source is TMG source, and the growth atmosphere is switched to _H2 atmosphere;

13) Place the epitaxial wafer obtained in step 12) in an O ₂ atmosphere, and anneal at 350° C. for 60 min to obtain an LED epitaxial wafer with a low-ohmic contact p-type GaN layer.

Example 28

Compared with Embodiment 26, this embodiment differs in that:

12) On the epitaxial wafer obtained in step 11), grow a p-type GaN rear layer with a thickness of 10 nm under the conditions of a temperature of 1000°C and a growth pressure of 100 torr, with a Mg doping concentration of 5×10 ²⁰ cm ^-3 , and grow The required Ga source is TMG source, and the growth atmosphere is switched to _H2 atmosphere;

13) Place the epitaxial wafer obtained in step 12) in an O ₂ atmosphere, and anneal at 950° C. for 1 min to obtain an LED epitaxial wafer with a low-ohmic contact p-type GaN layer.

For the LED epitaxial wafers of Example 26, Example 27, and Example 28, the circular transmission line model test shows that the ohmic contact resistance between the p-type GaN layer and the transparent conductive material ITO is on the order of 10 ^-5 Ω/cm, compared with the conventional p Type GaN and transparent conductive material ITO are reduced by an order of magnitude, respectively 4.2×10 ^-5 Ω/cm, 5.5×10 ^-5 Ω/cm and 3.5×10 ^-5 Ω/cm, blue LED chips with a size of 350mil×350min in Under the working condition of 20mAa current, the voltage drops by 0.02V, 0.04V and 0.02V. The experimental results show that the doping concentration of p-type GaN in this embodiment only needs to reach 10 ¹⁸ cm ^-3 to achieve low ohmic contact resistance, while conventional p-type GaN The doping concentration must reach at least 5×10 ¹⁹ cm ^-3 or more.

Comparative example 3

The difference between this comparative example and Example 14 lies in that: TMG source spin coating is not used, and a GaN stress relief buffer layer is not grown.

The surface dislocation density of the epitaxial wafer obtained in this comparative example was controlled to be 8.8×10 ⁸ cm ^-2 , and the surface roughness Ra of the epitaxial wafer was 0.7nm.

Comparative example 4

The difference between this comparative example and Example 14 lies in that a 100 nm GaN stress relief buffer layer is directly grown by MOCVD epitaxial growth instead of using TMG source spin coating.

The surface dislocation density of the epitaxial wafer obtained in this comparative example was controlled to be 6.8×10 ⁸ cm ^-2 , and the surface roughness Ra of the epitaxial wafer was 0.7nm.

Comparative example 5

The difference between this comparative example and Example 14 is that no Ni nanoparticles are added to the TMG source.

The surface dislocation density of the epitaxial wafer obtained in this comparative example was controlled to be 5.2×10 ⁸ cm ^-2 , and the surface roughness Ra of the epitaxial wafer was 0.7nm.

Comparative example 6

The difference between this comparative example and Example 14 is that it does not include placing the substrate with the MO source coating layer in the MOCVD reaction chamber in step 4), and does not perform annealing and recrystallization.

The surface of the epitaxial wafer obtained in this comparative example showed densely distributed pit defects, the dislocation density was controlled to be 9.8×10 ⁸ cm ^-2 , and the surface roughness Ra of the epitaxial wafer was 1.2nm.

The photoelectric performance data of Example 14 and Comparative Example 3, Comparative Example 4, Comparative Example 5, and Comparative Example 6 are confirmed by testing as shown in Table 2 below. It can be found that the embodiment has higher brightness and lower brightness under the same current test conditions. voltage, and has high antistatic properties.

The photoelectric performance data of the epitaxial wafer obtained by table 2 embodiment 14 and comparative examples 3-6

It should be understood that the LED epitaxial wafer preparation method in this application is not limited to the above-mentioned embodiment, which is a preferred embodiment of this application, but as long as the underlying structure is epitaxially grown by spin-coating nanoparticle precursors, it belongs to this application. scope of protection.

It will be apparent to those skilled in the art that the present application is not limited to the details of the exemplary embodiments described above, but that the present application can be implemented in other specific forms without departing from the spirit or essential characteristics of the present application. Accordingly, the embodiments should be considered exemplary and non-restrictive in every respect, and the scope of the application is defined by the appended claims rather than the foregoing description, and it is therefore intended that the scope of the present application be defined by the appended claims rather than by the foregoing description. All New Year's greetings within the meaning and scope of equivalent requirements are included in this application. Any reference signs in a claim should not be construed as limiting the claim concerned.

Claims

A method for preparing a semiconductor epitaxial wafer, the semiconductor epitaxial wafer comprising a substrate, and a semiconductor epitaxial structure, characterized in that the preparation method comprises:

Provide Group III metal-organic source hybrid precursors containing uniformly dispersed nanomaterials;

Coating the group III metal-organic source mixed precursor at least between the substrate and the semiconductor epitaxial structure, or between at least two functional layers of the semiconductor epitaxial structure, to obtain a group III metal organic source mixed precursor coating layer, and then the structure with Group III metal-organic source mixed precursor coating layer is placed in the MOCVD reaction chamber, and the Group III metal-organic source is introduced, and the group V element source and the reducing gas Annealing and recrystallization are carried out in a mixed atmosphere, thereby forming uniformly distributed nanomaterials and III-V group compound nanometer growth structures, and obtaining semiconductor epitaxial wafers.
The preparation method according to claim 1, wherein the nanomaterials include any one or more combinations of zero-dimensional nanomaterials, one-dimensional nanomaterials, two-dimensional nanomaterials, and three-dimensional nanomaterials; and/or Or, the mass ratio of nanomaterials to group III metal-organic sources in the mixed precursor is less than 1:1; and/or, the morphology of the nanomaterials includes any of nanoparticles, nanowires, nanofilms, and nanoblocks. One or a combination of two or more; and/or, the nanomaterials include any one or a combination of two or more of metal nanomaterials, non-metallic inorganic nanomaterials, and organic compound nanomaterials.
The preparation method according to claim 1, wherein the nanomaterials include Si 3 N 4 , SiO 2 , GaN, AlN, InN, SiC, ScAlN, Al 2 O 3 , Si, C, TiC, TiN, WC, WC-CO, B 4 C , BN, TiB 2 , LaF 3 , MoS 2 , ZrB 2 , ZnS, ZnSe, ZnO, Fe 3 O 4 , Ta 2 O 5 , SnO 2 , TiO 2 , ZrO 2 , Any one or a combination of two or more of Ni, Au, Ag, Fe, Co, Mn, Ti, Mg, Al, Ga, In, polystyrene, perovskite, graphene, preferably SiN, SiO2 , GaN, AlN, InN, SiC, ScAlN, Al 2 O 3 , Si, C, TiC, TiN, BN, ZnS, ZnSe, ZnO, TiO 2 , Ni, Au, Ag, Fe, Co, Mn, Ti, Mg , Al, graphene any one or a combination of two or more, especially preferably the nanomaterials include Si 3 N 4 , SiO 2 , GaN, AlN, SiC, ScAlN, Al 2 O 3 , TiO 2 , Ni , Al, Ga, graphene any one or a combination of two or more;

And/or, the diameter of the nanomaterial is 5-500nm;

And/or, the Group III elements contained in the Group III metal-organic source include any one or a combination of two or more of indium, gallium, and aluminum; the Group III metal-organic source includes a Group III organic compound source, and the Group III organic compound sources include any one or a combination of two or more of indium sources, gallium sources, and aluminum sources; the indium sources include any of trimethylindium, triethylindium, and dimethylethylindium One or a combination of two or more, the gallium source includes any one or a combination of two or more of trimethylgallium, triethylgallium, and triisopropylgallium, and the aluminum source includes trimethylaluminum, triethylaluminum, Any one or a combination of two or more of dimethylaluminum alkoxide, dimethylaluminum hydride, and alane complexes;

And/or, the Group V elements contained in the Group V element source include any one or a combination of two or more of nitrogen, phosphorus, and arsenic; the Group V element source includes nitrogen source, phosphorus source, and arsenic source. Any one or a combination of two or more; the nitrogen source includes any one or a combination of two or more of NH 3 , organic amine compounds, and trap compounds; the organic amine compounds include alkylamines, so Said alkylamine includes tert-butylamine and/or n-propylamine, said hydrazine compound includes dimethyl hydrazine; said phosphorus source includes PH 3 and/or organic phosphorus source, and said organic phosphorus source includes tert-butyl phosphorus ; The arsenic source includes AsH 3 and/or an organic arsenic source, the organic arsenic source includes tert-butyl arsenic;

And/or, the reducing gas includes H 2 ; and/or, the flow ratio of the group V element source and the reducing gas in the mixed atmosphere is 10:1˜100:1.
The preparation method according to claim 1, is characterized in that, comprising:

Provide Group III metal-organic source hybrid precursors containing uniformly dispersed nanomaterials;

Coating the Group III metal-organic source mixed precursor on the substrate to obtain the Group III metal-organic source mixed precursor coating layer, and then placing the substrate with the Group III metal-organic source mixed precursor coating layer on In the MOCVD reaction chamber, the metal-organic source of group III is introduced, and annealing and recrystallization are carried out in the mixed atmosphere of group V element source and reducing gas, so as to form uniformly distributed nanomaterials and nano-growth structures of group III-V compounds, and obtain Stress relief buffer layer;

The unintentionally doped nitride layer, n-type nitride layer, light-emitting layer, electron blocking layer and p-type nitride layer are sequentially grown on the stress release buffer layer to form a semiconductor epitaxial structure, thereby producing a semiconductor epitaxial wafer.
The preparation method according to claim 4, is characterized in that, comprises the following steps:

1) providing a substrate, the substrate is sapphire, silicon carbide, silicon, zinc oxide, gallium nitride or gallium arsenide;

2) In N2 atmosphere, apply the group III metal-organic source mixed precursor on the substrate by spin coating, and form a group III metal-organic source mixed precursor coating with a thickness of 20 nm to 2000 nm on the substrate. cladding;

3) Place the substrate with the mixed precursor coating layer of Group III metal-organic source in the reaction chamber of the MOCVD growth equipment. The group metal-organic source is a group III organic compound source, the reaction chamber is heated to 500-1200°C, and the group V element source and reducing gas are introduced to carry out annealing and recrystallization for 10s-100s, and then grow to obtain a thickness of 10-100°C. 100nm stress relief buffer layer;

4) growing an unintentionally doped nitride layer on the stress release buffer layer, the unintentionally doped nitride layer is an unintentionally doped GaN layer, the Ga source required for growth is a TMG source, and the growth atmosphere is H 2 Atmosphere, the growth temperature is 1000-1200°C, and the growth pressure is 100-600torr;

5) growing an n-type nitride layer on the unintentionally doped nitride layer, the n-type nitride layer is an n-type GaN layer, and the doping concentration of Si is 2×10 18 cm −3 to 5×10 19 cm -3 ; the Ga source required for growth is TMG source, the growth atmosphere is H 2 atmosphere, the growth temperature is 1000~1200℃, and the growth pressure is 100~600torr;

6) Growing a light-emitting layer on the n-type nitride layer, and growing 1 to 20 pairs of InGaN/GaN multi-quantum well light-emitting layers together, and the InGaN/GaN multi-quantum well light-emitting layer includes periodically repeated and alternately grown InGaN quantum wells layer and GaN quantum barrier layer, the thickness of the InGaN quantum well layer is 2-6nm, the Ga source required for growth is TEG source, the In source is TMIn source, the growth atmosphere is N2 atmosphere, and the growth temperature is 700-900°C , the growth pressure is 200-500torr; the thickness of the GaN quantum barrier layer is 6-20nm, the Ga source required for growth is TEG source, the growth atmosphere is H2 atmosphere, the growth temperature is 750-950°C, and the growth pressure is 200 ~500torr;

7) growing an electron blocking layer on the light-emitting layer, the electron blocking layer is a p-type AlGaN electron blocking layer, the Ga source required for growth is a TMG source, the Al source is a TMAl source, and the growth atmosphere is a N2 atmosphere, and the growth The temperature is 950~1050℃, and the growth pressure is 100~200torr;

8) growing a p-type nitride layer on the electron blocking layer, the p-type nitride layer is a p-type GaN layer, and the doping concentration of Mg is 1×10 18 cm −3 to 5×10 20 cm −3 ; The Ga source required for growth is TMG source, the growth atmosphere is H 2 atmosphere, the growth temperature is 950-1050°C, and the growth pressure is 200-600torr.
The preparation method according to claim 1, wherein the semiconductor epitaxial wafer comprises a substrate, a nitride buffer layer, an unintentionally doped nitride layer, an n-type nitride layer, a nitride multi-quantum well light-emitting layer, p-type nitride electron blocking layer, p-type nitride layer, the preparation method includes:

Provide Group III metal-organic source hybrid precursors containing uniformly dispersed nanomaterials;

Coating the group III metal-organic source mixed precursor at least on any one of the unintentionally doped nitride layer, n-type nitride layer, and p-type nitride layer to obtain the group III metal-organic source mixed precursor coating layer, and then place the composite structure with the mixed precursor coating layer of group III metal-organic source in the MOCVD reaction chamber, pass through the group III metal-organic source, in the mixed atmosphere of group V element source and reducing gas Annealing and recrystallization are performed to form nucleation centers with uniform distribution of nanomaterials and III-V group compound nanogrowth structures, and to obtain a metal-organic source insertion layer.
The preparation method according to claim 6, is characterized in that, comprising:

sequentially growing a nitride buffer layer, an unintentionally doped nitride layer and an n-type nitride layer on the substrate;

Coating the Group III metal-organic source mixed precursor on the n-type nitride layer to obtain the Group III metal-organic source mixed precursor coating layer, and then compounding the Group III metal-organic source mixed precursor coating layer The structure is placed in the MOCVD reaction chamber, and the group III metal organic source is passed through, and annealing and recrystallization are carried out in the mixed atmosphere of the V group element source and the reducing gas, so as to form nanomaterials and III-V compound nano-growth structures with uniform distribution The nucleation center of the metal-organic source intercalation layer is obtained;

growing a quantum barrier modification layer on the surface of the metal-organic source insertion layer, and then growing a quantum well layer to form a first light-emitting layer;

And, continue to grow nitride multi-quantum well light-emitting layer, p-type nitride electron blocking layer, p-type nitride layer, and produce high light-efficiency semiconductor epitaxial wafer with low-stress quantum well light-emitting layer.
The preparation method according to claim 7, is characterized in that, specifically comprises the following steps:

1) providing a substrate, and growing a nitride buffer layer with a thickness of 20-60 nm on the substrate under the growth condition of a temperature of 400-600° C.;

2) growing an unintentionally doped nitride layer with a thickness of 2-4 μm on the nitride buffer layer under the growth conditions of a temperature of 1040-1100° C. and a pressure of 100-300 torr;

3) growing an n-type nitride layer with a thickness of 2-4 μm on the unintentionally doped nitride layer under the growth conditions of a temperature of 1040-1070° C. and a pressure of 100-200 torr, with a doping concentration of 2× 10 18 cm -3 ～5×10 19 cm -3 ;

4) In N2 atmosphere, apply the group III metal-organic source mixed precursor on the n-type nitride layer by spin coating, and form a group III metal with a thickness of 10nm to 1000nm on the n-type nitride layer Organic source mixed precursor coating layer;

5) Place the composite structure with the mixed precursor coating layer of group III metal-organic source in the reaction chamber of the MOCVD growth equipment, the pressure in the reaction chamber is 100-600 torr, feed the group III metal-organic source, and the III The group metal organic source is a group III organic compound source, the reaction chamber is heated to 500-1200°C, and the source of group V elements and reducing gas are introduced to carry out annealing and recrystallization for 10s-100s, and then grow to obtain a thickness of 1-200°C. 100nm metal-organic source insertion layer;

6) Under the growth conditions of a temperature of 700-950°C and a pressure of 50-350 torr, a quantum barrier modification layer with a thickness of 10nm-500nm is formed on the surface of the metal-organic source insertion layer; and then a quantum barrier modification layer with a thickness of 2-6nm is grown. a well layer, forming a first light-emitting layer;

7) Under the growth conditions of a temperature of 750-900° C. and a pressure of 100-300 torr, a nitride multi-quantum well light-emitting layer is grown on the quantum well layer, and the nitride multi-quantum well light-emitting layer includes periodically repeated alternating The grown nitride quantum well layer and nitride quantum barrier layer have a growth period of 1 to 20, the thickness of the nitride quantum well layer is 2 to 6 nm, and the thickness of the nitride quantum barrier layer is 6 to 20 nm;

8) growing a p-type nitride electron blocking layer with a thickness of 15-150 nm on the nitride multi-quantum well light-emitting layer under the growth conditions of a temperature of 800-1000° C. and a pressure of 100-400 torr;

9) growing a p-type nitride layer with a thickness of 20-200 nm on the p-type nitride electron blocking layer under the growth conditions of a temperature of 800-1000° C. and a pressure of 100-400 torr, with a doping concentration of 1× 10 18 cm -3 ～5×10 20 cm -3 ;

And/or, the substrate comprises sapphire, silicon carbide, silicon, zinc oxide or gallium nitride;

And/or, the material of the nitride buffer layer, the unintentionally doped nitride layer, the n-type nitride layer, the nitride multi-quantum well light-emitting layer, the p-type nitride electron blocking layer, and the p-type nitride layer includes GaN , AlN, InN, InGaN, AlInN, AlGaN, AlInGaN any one or a combination of two or more;

And/or, the preparation method includes: growing the quantum barrier modification layer by using a lateral epitaxial growth process;

And/or, the preparation method includes: growing the quantum barrier modification layer by using a vertical epitaxy combined with a lateral epitaxy growth process.
The preparation method according to claim 6, is characterized in that, comprising:

On the substrate, sequentially grow a nitride buffer layer, an unintentionally doped nitride layer, an n-type nitride layer, a nitride multi-quantum well light-emitting layer, a p-type nitride electron blocking layer, and a p-type nitride front layer;

Coating the Group III metal-organic source mixed precursor on the p-type nitride front layer to obtain the Group III metal-organic source mixed precursor coating layer, and then applying the Group III metal-organic source mixed precursor coating layer The composite structure is placed in the MOCVD reaction chamber, and the Group III metal-organic source is introduced, and annealing and recrystallization are carried out in the mixed atmosphere of the V group element source and the reducing gas, so as to form nanomaterials and III-V compounds with a uniform nano-growth structure Distributed nucleation centers, resulting in metal-organic source insertion layers;

epitaxially growing a p-type nitride rear layer on the surface of the metal-organic source insertion layer;

And, performing annealing treatment on the obtained epitaxial structure to prepare a semiconductor epitaxial wafer with low ohmic contact p-type nitride.
The preparation method according to claim 9, is characterized in that, specifically comprises the following steps:

1) providing a substrate, and growing a nitride buffer layer with a thickness of 20-60 nm on the substrate under the growth condition of a temperature of 400-600° C.;

2) growing an unintentionally doped nitride layer with a thickness of 2-4 μm on the nitride buffer layer under the growth conditions of a temperature of 1040-1100° C. and a pressure of 100-300 torr;

3) growing an n-type nitride layer with a thickness of 2-4 μm on the unintentionally doped nitride layer under the growth conditions of a temperature of 1040-1070° C. and a pressure of 100-200 torr, with a doping concentration of 2× 10 18 cm -3 ～5×10 19 cm -3 ;

4) Under the growth conditions of a temperature of 750-900° C. and a pressure of 100-300 torr, a nitride multi-quantum well light-emitting layer is grown on the n-type nitride layer, and the nitride multi-quantum well light-emitting layer includes a periodic The nitride quantum well layer and the nitride quantum barrier layer are repeatedly grown alternately, the growth period is 1-20, the thickness of the nitride quantum well layer is 2-6nm, and the thickness of the nitride quantum barrier layer is 6-20nm ;

5) growing a p-type nitride electron blocking layer with a thickness of 15-150 nm on the nitride multi-quantum well light-emitting layer under the growth conditions of a temperature of 800-1000° C. and a pressure of 100-400 torr;

6) growing a p-type nitride front layer with a thickness of 20-200 nm on the p-type nitride electron blocking layer under the growth conditions of a temperature of 800-1000° C. and a pressure of 100-400 torr, with a doping concentration of 1 ×10 18 cm -3 ～5×10 20 cm -3 ;

7) In N2 atmosphere, apply the group III metal-organic source mixed precursor on the p-type nitride front layer by spin coating, and form a III layer with a thickness of 10-1000 nm on the p-type nitride front layer. Group metal-organic source mixed precursor coating layer;

8) Place the composite structure with the mixed precursor coating layer of group III metal-organic source in the reaction chamber of the MOCVD growth equipment, the pressure in the reaction chamber is 100-600 torr, and the group III metal-organic source is introduced, and the group III The group metal organic source is a group III organic compound source, the reaction chamber is heated to 500-1200°C, and the source of group V elements and reducing gas are introduced to carry out annealing and recrystallization for 10s-100s, and then grow to obtain a thickness of 1-200°C. 100nm metal-organic source insertion layer;

9) Under the growth conditions of a temperature of 800-1000° C. and a pressure of 100-400 torr, a p-type nitride rear layer with a thickness of 2-20 nm is grown on the metal-organic source insertion layer, and the doping concentration is 1×10 18 cm -3 ～5×10 20 cm -3 ;

10) placing the obtained epitaxial structure in a mixed atmosphere containing an oxidizing gas, and performing annealing treatment at 350-950° C. for 1-60 minutes to obtain the semiconductor epitaxial wafer;

And/or, the substrate comprises sapphire, silicon carbide, silicon, zinc oxide or gallium nitride;

And/or, the nitride buffer layer, unintentionally doped nitride layer, n-type nitride layer, nitride multi-quantum well light-emitting layer, p-type nitride electron blocking layer, p-type nitride front layer, p-type The material of the nitride rear layer includes any one or a combination of two or more of GaN, AlN, InN, InGaN, AlInN, AlGaN, AlInGaN.
The preparation method according to claim 6, is characterized in that, comprising:

sequentially growing a nitride buffer layer and an unintentionally doped nitride layer on the substrate;

Coating the group III metal-organic source mixed precursor on the unintentionally doped nitride layer to obtain the group III metal-organic source mixed precursor coating layer, and then coating the group III metal-organic source mixed precursor coating layer The composite structure is placed in the MOCVD reaction chamber, and the Group III metal-organic source is introduced, and annealing and recrystallization are performed in the mixed atmosphere of the V group element source and the reducing gas, thereby forming nanomaterials and III-V compound nano-growth structures Uniformly distributed nucleation centers, resulting in metal-organic source insertion layers;

And, continue to grow n-type nitride layer, nitride multi-quantum well light-emitting layer, p-type nitride electron blocking layer, p-type nitride layer on the metal-organic source insertion layer to obtain the low-stress quantum well light-emitting layer High-efficiency semiconductor epitaxial wafers.
The preparation method according to claim 11, is characterized in that, specifically comprises the following steps:

1) providing a substrate, and growing a nitride buffer layer with a thickness of 20-60 nm on the substrate under the growth condition of a temperature of 400-600° C.;

2) growing an unintentionally doped nitride layer with a thickness of 2-4 μm on the nitride buffer layer under the growth conditions of a temperature of 1040-1100° C. and a pressure of 100-300 torr;

3) In N2 atmosphere, apply the group III metal-organic source mixed precursor on the unintentionally doped nitride layer by spin coating, and form a layer with a thickness of 10nm to 1000nm on the unintentionally doped nitride layer. Group III metal-organic source mixed precursor coating layer;

4) Place the composite structure with the mixed precursor coating layer of group III metal-organic source in the reaction chamber of the MOCVD growth equipment, the pressure in the reaction chamber is 100-600 torr, and the group III metal-organic source is introduced, and the group III The group metal organic source is a group III organic compound source, the reaction chamber is heated to 500-1200°C, and the source of group V elements and reducing gas are introduced to carry out annealing and recrystallization for 10s-100s, and then grow to obtain a thickness of 1-200°C. 100nm metal-organic source insertion layer;

5) growing an n-type nitride layer with a thickness of 2-4 μm on the metal-organic source insertion layer under the growth conditions of a temperature of 1040-1070° C. and a pressure of 100-200 torr, with a doping concentration of 2×10 18 cm -3 ～5×10 19 cm -3 ;

6) Under the growth conditions of a temperature of 750-900° C. and a pressure of 100-300 torr, a nitride multi-quantum well light-emitting layer is grown on the n-type nitride layer, and the nitride multi-quantum well light-emitting layer includes a periodic The nitride quantum well layer and the nitride quantum barrier layer are repeatedly grown alternately, the growth period is 1-20, the thickness of the nitride quantum well layer is 2-6nm, and the thickness of the nitride quantum barrier layer is 6-20nm ;

7) growing a p-type nitride electron blocking layer with a thickness of 15-150 nm on the nitride multi-quantum well light-emitting layer under the growth conditions of a temperature of 800-1000° C. and a pressure of 100-400 torr;

8) growing a p-type nitride layer with a thickness of 20-200 nm on the p-type nitride electron blocking layer under the growth conditions of a temperature of 800-1000° C. and a pressure of 100-400 torr, with a doping concentration of 1× 10 18 cm -3 ～5×10 20 cm -3 ;

And/or, the substrate comprises sapphire, silicon carbide, silicon, zinc oxide or gallium nitride;

And/or, the material of the nitride buffer layer, the unintentionally doped nitride layer, the n-type nitride layer, the nitride multi-quantum well light-emitting layer, the p-type nitride electron blocking layer, and the p-type nitride layer includes GaN , AlN, InN, InGaN, AlInN, AlGaN, AlInGaN any one or a combination of two or more.
The semiconductor epitaxial wafer prepared by the method according to any one of claims 1-5, the semiconductor epitaxial wafer comprises a substrate on which a stress release buffer layer and a semiconductor epitaxial structure are sequentially formed; wherein, the The stress release buffer layer is formed by annealing and recrystallizing the Group III metal-organic source mixed precursor coating layer covering the surface of the substrate.
The semiconductor epitaxial wafer according to claim 13, characterized in that: the semiconductor epitaxial wafer is a light-emitting diode epitaxial wafer, and the light-emitting diode epitaxial wafer includes a substrate, a stress relief buffer layer sequentially located thereon, unintentional doping Nitride layer, n-type nitride layer, light emitting layer, electron blocking layer, p-type nitride layer;

And/or, the unintentionally doped nitride layer is an unintentionally doped GaN layer with a thickness of 1-4 μm;

And/or, the n-type nitride layer is an n-type GaN layer with a thickness of 1-4 μm, and the doping concentration of Si is 2×10 18 cm −3 to 5 ×10 19 cm −3 ;

And/or, the light-emitting layer is an InGaN/GaN multi-quantum well light-emitting layer, and the InGaN/GaN multi-quantum well light-emitting layer includes InGaN quantum well layers and GaN quantum barrier layers that are periodically and alternately grown, and the repetition period is 1- 20. The InGaN quantum well layer has a thickness of 2-6 nm, and the GaN quantum barrier layer has a thickness of 6-20 nm;

And/or, the electron blocking layer is a p-type AlGaN electron blocking layer with a thickness of 15-150 nm;

And/or, the p-type nitride layer is a p-type GaN layer with a thickness of 20-200 nm, and the doping concentration of Mg is 1×10 18 cm −3 to 5×10 20 cm −3 .
The semiconductor epitaxial wafer prepared by the method according to any one of claims 1-3, 6, said semiconductor epitaxial wafer comprising a substrate, a nitride buffer layer, an unintentionally doped nitride layer, an n-type nitride layer, a nitrogen Compound multi-quantum well light-emitting layer, p-type nitride electron blocking layer, p-type nitride layer, at least any one of the non-intentionally doped nitride layer, n-type nitride layer, p-type nitride layer is formed on the surface There is a metal-organic source insertion layer, and the metal-organic source insertion layer is formed by annealing and recrystallization of the Group III metal-organic source mixed precursor coating layer covered on its surface.