CN117995952A - Preparation method of electron injection layer for deep ultraviolet light-emitting diode - Google Patents
Preparation method of electron injection layer for deep ultraviolet light-emitting diode Download PDFInfo
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Abstract
The invention provides a preparation method of an electron injection layer for a deep ultraviolet light emitting diode, which comprises the following steps: firstly, nitriding a substrate, secondly, epitaxially growing a first buffer layer on the substrate, thirdly, epitaxially growing a second buffer layer on the first buffer layer, thirdly, epitaxially growing a third buffer layer on the second buffer layer, thirdly, epitaxially growing a fourth buffer layer on the third buffer layer, thirdly, epitaxially growing a fifth buffer layer on the fourth buffer layer, and finally, epitaxially growing an electron injection layer on the fifth buffer layer, wherein the first buffer layer and the third buffer layer are both Si-doped AlN materials, and the second buffer layer is an unintentionally-doped AlN material; the fourth buffer layer and the electron injection layer are both made of Si-doped AlGaN materials, and the fifth buffer layer is made of unintentionally-doped AlGaN materials; the preparation method can improve the surface morphology of the electron injection layer and improve the luminous efficiency of the deep ultraviolet light-emitting diode.
Description
Technical Field
The invention relates to the field of semiconductor photoelectricity, in particular to a preparation method of an electron injection layer for a deep ultraviolet light-emitting diode.
Background
Among ultraviolet rays, light having a wavelength of 200 nm to 350 nm is called deep ultraviolet rays. The deep ultraviolet light emitting diode has great application value in the fields of illumination, sterilization, medical treatment, printing, biochemical detection, high-density information storage, secret communication and the like because of the advantages of high efficiency, environmental protection, energy conservation, reliability and the like, which are incomparable with the common ultraviolet light emitting diode.
The electron injection layer of the deep ultraviolet light emitting diode generally uses an AlGaN film with a high Al composition content, and the AlGaN film generally needs to be grown on an AlN material in order to prevent cracking of the AlGaN film and improve the crystal quality of the AlGaN film. However, an AlGaN thin film grown on an AlN material receives compressive stress from the AlN material, and excessive compressive stress may cause roughening of the surface of the AlGaN thin film, and the crystal quality is degraded, thereby causing a decrease in the luminous efficiency of the deep ultraviolet light emitting diode.
Therefore, the high-quality electron injection layer is the basis for preparing the high-performance deep ultraviolet light-emitting diode. Although the existing AlGaN film growth technology has greatly advanced, the technical problem of how to prepare high-quality AlGaN films is still a current technical difficulty.
Disclosure of Invention
The invention aims to provide a preparation method of an electron injection layer for a deep ultraviolet light emitting diode, which is used for solving the technical problem that the growth quality of the electron injection layer of the existing deep ultraviolet light emitting diode is low.
In order to solve the technical problems, the invention provides a preparation method of an electron injection layer for a deep ultraviolet light emitting diode, which comprises the following steps:
s10, nitriding a substrate;
s20, epitaxially growing a first buffer layer on the substrate;
S30, epitaxially growing a second buffer layer on the first buffer layer;
s40, epitaxially growing a third buffer layer on the second buffer layer;
s50, epitaxially growing a fourth buffer layer on the third buffer layer;
S60, epitaxially growing a fifth buffer layer on the fourth buffer layer;
s70, epitaxially growing an electron injection layer on the fifth buffer layer;
The first buffer layer and the third buffer layer are both made of Si-doped AlN materials, and the second buffer layer is made of an unintentionally-doped AlN material; the fourth buffer layer and the electron injection layer are both Si-doped AlGaN materials, and the fifth buffer layer is an unintentionally doped AlGaN material.
Preferably, the step S10 specifically includes:
s101, placing a substrate in a reaction cavity of MOCVD equipment;
S102, introducing hydrogen and ammonia into a reaction cavity, wherein the flux of the ammonia and the hydrogen is 1:1-1:20, the introducing time is 1-20 min, and the temperature of the reaction cavity is 1100-1500 ℃;
S103, stopping introducing ammonia gas, and introducing SiH 4 gas, wherein the flux of SiH 4 gas and hydrogen gas is 1:5-1:100.
Preferably, the first buffer layer is prepared by in-situ growth or physical vapor deposition.
Preferably, the thickness of the first buffer layer is 5 nm-30 nm, and the Si doping concentration of the first buffer layer is 1E19cm -3～1E21cm-3.
Preferably, the thickness of the second buffer layer is 500nm to 3000nm.
Preferably, the surface roughness of the second buffer layer is less than or equal to 2nm at a 10 μm region.
Preferably, the thickness of the third buffer layer is 100nm to 2000nm, and the Si doping concentration of the third buffer layer is 1E17cm -3～1E19cm-3.
Preferably, the growth temperature of the third buffer layer is less than or equal to the growth temperature of the second buffer layer.
Preferably, the thickness of the fourth buffer layer is 100 nm-1000 nm, and the Si doping concentration of the fourth buffer layer is 1E17cm -3～1E19cm-3; the thickness of the fifth buffer layer is 100 nm-2000 nm.
Preferably, the fourth buffer layer has an Al component content of x, the fifth buffer layer has an Al component content of y, and the electron injection layer has an Al component content of z;
Wherein the relationship between x, y and z is as follows: and z is less than or equal to y is less than or equal to x is less than or equal to (y+100%)/2.
The beneficial effects of the invention are as follows: the present invention provides a method for preparing an electron injection layer for a deep ultraviolet light emitting diode, which comprises: firstly, nitriding a substrate, secondly, epitaxially growing a first buffer layer on the substrate, thirdly, epitaxially growing a second buffer layer on the first buffer layer, thirdly, epitaxially growing a third buffer layer on the second buffer layer, thirdly, epitaxially growing a fourth buffer layer on the third buffer layer, thirdly, epitaxially growing a fifth buffer layer on the fourth buffer layer, and finally, epitaxially growing an electron injection layer on the fifth buffer layer, wherein the first buffer layer and the third buffer layer are both Si-doped AlN materials, and the second buffer layer is an unintentionally-doped AlN material; the fourth buffer layer and the electron injection layer are both made of Si-doped AlGaN materials, and the fifth buffer layer is made of unintentionally-doped AlGaN materials; according to the preparation method, firstly, the interface between the AlN material and the substrate is subjected to nitriding treatment, meanwhile, the AlN material and the AlGaN material are respectively subjected to interval Si doping treatment, so that the compressive stress born by the electron injection layer can be reduced, the crystal quality of the electron injection layer is improved, the surface morphology of the electron injection layer is further improved, and finally the luminous efficiency of the deep ultraviolet light-emitting diode is improved.
Drawings
Fig. 1 is a process flow diagram of a method for preparing an electron injection layer for a deep ultraviolet light emitting diode according to an embodiment of the present invention;
Fig. 2 is a schematic diagram of an epitaxial structure of an electron injection layer for a deep ultraviolet light emitting diode on a substrate according to an embodiment of the present invention;
FIG. 3 is a schematic diagram of SIMS performed near a first buffer layer in a method for manufacturing an electron injection layer for a deep ultraviolet light emitting diode according to an embodiment of the present invention;
FIG. 4 is a schematic diagram of SIMS performed near a third buffer layer in a method for manufacturing an electron injection layer for a deep ultraviolet light emitting diode according to an embodiment of the present invention;
Fig. 5 is a schematic diagram of SIMS located near a fourth buffer layer and a fifth buffer layer in a method for manufacturing an electron injection layer for a deep ultraviolet light emitting diode according to an embodiment of the present invention.
Detailed Description
The technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention, and it is apparent that the described embodiments are only some embodiments of the present invention, not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the present invention without making any inventive effort, are intended to fall within the scope of the present invention.
Most steps of the preparation method of the embodiment of the invention adopt MOCVD equipment of VeecoK465i model as growth equipment; wherein, high-purity H 2 or high-purity N 2 or mixed gas of high-purity H 2 and high-purity N 2 is used as carrier gas, high-purity NH 3 is used as nitrogen source, high-purity SiH 4 is used as silicon source, trimethylaluminum (TMAL) is used as aluminum source, and the pressure of a reaction cavity in MOCVD (metal organic chemical vapor deposition) equipment is controlled at 20-100 torr.
Referring to fig. 1 to 2, fig. 1 is a process flow chart of a method for preparing an electron injection layer 30 for a deep ultraviolet light emitting diode according to an embodiment of the invention; fig. 2 is a schematic diagram of an epitaxial structure of an electron injection layer 30 for a deep ultraviolet light emitting diode on a substrate 10 according to an embodiment of the present invention; the preparation method specifically comprises the following steps:
S10, nitriding the substrate 10.
Specifically, S10 further includes:
Firstly, providing a substrate 10, wherein the substrate 10 is made of sapphire material; sapphire materials have many advantages: firstly, the production technology of the sapphire material is mature, and the quality of the device is good; secondly, the sapphire has good stability and can be applied to a high-temperature growth process; finally, the sapphire has high mechanical strength and is easy to process and clean. Therefore, most processes typically use sapphire as the substrate 10.
Thereafter, the substrate 10 is subjected to nitriding treatment.
In a first embodiment, the nitriding process comprises:
S101, placing a substrate 10 in a reaction cavity of MOCVD equipment;
S102, introducing hydrogen and ammonia into a reaction cavity, wherein the flux of the ammonia and the hydrogen is 1:1-1:20, the introducing time is 1-20 min, and the temperature of the reaction cavity is 1100-1500 ℃;
S103, stopping introducing ammonia gas, and introducing SiH 4 gas, wherein the flux of SiH 4 gas and hydrogen gas is 1:5-1:100.
In a second embodiment, the nitriding process comprises:
S101, placing a substrate 10 in a reaction cavity of MOCVD equipment;
s102, continuously introducing hydrogen into a reaction cavity for 1-20 min, wherein the temperature of the reaction cavity is 1100-1500 ℃;
s102, introducing ammonia gas into the reaction cavity in a hydrogen atmosphere, wherein the flux of the ammonia gas and the hydrogen gas is 1:1-1:20, the introducing time is 1-20 min, and the temperature of the reaction cavity is 1100-1500 ℃;
S103, stopping introducing ammonia under the hydrogen atmosphere, and introducing SiH 4 gas, wherein the flux of SiH 4 gas and hydrogen is 1:5-1:100.
Specifically, the substrate 10 of sapphire material is subjected to nitriding treatment mainly to embed a certain amount of nitrogen bonds on the surface of the sapphire material, so that the subsequent epitaxial growth can be performed better.
S20, epitaxially growing a first buffer layer 21 on the substrate 10.
Specifically, S20 further includes:
the first buffer layer 21 is grown on the substrate 10 in situ or by physical vapor deposition, the first buffer layer 21 is an AlN material doped with Si, and the growth temperature is 400-800 ℃.
Specifically, when the first buffer layer 21 is grown in situ on the substrate 10, the nitriding process in step S10 is performed in the second embodiment; when the first buffer layer 21 is physically vapor deposited on the substrate 10, the nitriding process in step S10 is selected from the first embodiment, because excessive introduction of H 2 may cause corrosion to AlN material.
In the embodiment of the invention, the thickness of the first buffer layer 21 is 5 nm-30 nm, and the Si doping concentration of the first buffer layer 21 is 1E19cm -3～1E21cm-3; since the lattice mismatch between the substrate 10 (the main material of the sapphire material is AL 2O3) and the AlN material is large, a thin first buffer layer 21 needs to be grown before the AlN material is grown, and the first buffer layer 21 serves as a nucleation layer of the AlN material.
Specifically, the high concentration of Si doping of the first buffer layer 21 can effectively relieve the compressive stress generated by the AlN material.
S30, epitaxially growing the second buffer layer 22 on the first buffer layer 21.
Specifically, S30 further includes:
And epitaxially growing a second buffer layer 22 on the first buffer layer 21 by using MOCVD equipment, wherein the second buffer layer 22 is an unintentionally doped AlN material and has a thickness of 500-3000 nm, and the second buffer layer 22 is used as a high-temperature nucleation layer of the AlN material.
Preferably, after the second buffer layer 22 is grown, the surface of the epitaxial wafer needs to be flat, and no holes can exist; the surface roughness of the second buffer layer 22 at a 10 μm x 10 μm region is less than or equal to 2nm, as measured under an atomic force microscope; this indicates that the surface morphology of the second buffer layer 22 is good, and the dislocation density of the AlGaN material that is epitaxially grown on the second buffer layer 22 in the subsequent process can be effectively reduced.
And S40, epitaxially growing a third buffer layer 23 on the second buffer layer 22.
Specifically, S40 further includes:
and epitaxially growing a third buffer layer 23 on the second buffer layer 22, wherein the third buffer layer 23 is made of an AlN material doped with Si, the thickness is 100-2000 nm, the doping concentration of Si is 1E17cm -3～1E19cm-3, and the third buffer layer 23 is used as a stress relief layer of the AlN material.
Specifically, the growth temperature of the third buffer layer 23 is less than or equal to the growth temperature of the second buffer layer 22; this is because the growth temperature is increased, which is advantageous for the subsequent growth of AlGaN materials.
Preferably, the growth temperature of the second buffer layer 22 is 1000 to 1400 ℃, and the growth temperature of the third buffer layer 23 is 950 to 1350 ℃.
And S50, epitaxially growing a fourth buffer layer 24 on the third buffer layer 23.
Specifically, S50 further includes:
And epitaxially growing a fourth buffer layer 24 on the third buffer layer 23, wherein the fourth buffer layer 24 is made of an entire layer of Si-doped AlGaN material, the thickness of the fourth buffer layer 24 is 100-1000 nm, the Si doping concentration of the fourth buffer layer 24 is 1E17cm -3～1E19cm-3, and the growth temperature of the fourth buffer layer 24 is 800-1200 ℃.
Specifically, since the compressive stress of the interface of the AlN material and the AlGaN material is large, it is necessary to grow a fourth buffer layer 24 before growing the electron injection layer 30, and the fourth buffer layer 24 serves as a nucleation layer of the AlGaN material. Meanwhile, the whole layer of Si doping of the fourth buffer layer 24 can effectively relieve the compressive stress suffered by the subsequent electron injection layer 30.
And S60, epitaxially growing a fifth buffer layer 25 on the fourth buffer layer 24.
Specifically, S60 further includes:
Maintaining the growth temperature of MOCVD equipment unchanged, epitaxially growing a fifth buffer layer 25 on the fourth buffer layer 24, wherein the fifth buffer layer 25 is an unintentionally doped AlGaN material, the thickness of the fifth buffer layer 25 is 100-2000 nm, and the growth temperature of the fifth buffer layer 25 is 800-1200 ℃; the fifth buffer layer 25 serves as a transition layer for the subsequent preparation of the electron injection layer 30.
In one embodiment, the fourth buffer layer 24 has an Al composition of x, the fifth buffer layer 25 has an Al composition of y, and the electron injection layer 30 has an Al composition of z;
Wherein the relationship between x, y and z is as follows: and z is less than or equal to y is less than or equal to x is less than or equal to (y+100%)/2.
Specifically, when the Al component content of the fourth buffer layer 24 to the electron injection layer 30 linearly decreases in the growth direction, it is possible to play a role in releasing stress, suppressing dislocation, and improving the epitaxial crystallization quality.
S70, the electron injection layer 30 is epitaxially grown on the fifth buffer layer 25.
Specifically, S70 further includes:
Maintaining the growth temperature of the MOCVD equipment unchanged or reducing the growth temperature, epitaxially growing an electron injection layer 30 on the fifth buffer layer 25, wherein the electron injection layer 30 is made of silicon-doped aluminum gallium nitride material; wherein the composition of the aluminum element ranges from 20% to 90%, and the silicon dopant is SiH 4.
The technical scheme of the invention is further described with reference to specific embodiments.
Comparative example:
s10, heating the sapphire substrate 10 to 700 ℃ by using MOCVD equipment, respectively introducing TMAL, NH 3 and H 2 with the flow of 5000sccm under the pressure of 50Torr, and growing to form an AlN nucleation layer with the thickness of 20nm, wherein the V/III ratio is 10000;
S20, heating the reaction chamber to 1350 ℃ by using MOCVD equipment, respectively introducing TMAL and NH 3 under the pressure of 50Torr, and growing to form an AlN intrinsic layer with the thickness of 2500nm, wherein the V/III ratio is 1000;
S30, cooling the reaction cavity to 1100 ℃ by using MOCVD equipment, respectively introducing TMAL, TMGa and NH 3 under the pressure of 50Torr, and growing to form an AlGaN material layer with the thickness of 3300nm, wherein the V/III ratio is 1000, the Al component content of AlGaN is 50%, and the Si doping concentration is 1E20cm -3.
The embodiment of the invention comprises the following steps:
Referring to fig. 2, fig. 2 is a schematic diagram showing an epitaxial structure of an electron injection layer 30 for a deep ultraviolet light emitting diode on a substrate 10 according to an embodiment of the present invention; specifically, the specific preparation method of the electron injection layer 30 for a deep ultraviolet light emitting diode provided by the embodiment of the invention comprises the following steps:
S10, selecting a substrate 10 made of sapphire and containing a first buffer layer 21, and nitriding the substrate 10, wherein the thickness of the first buffer layer 21 is 20nm, and the substrate is prepared by a physical vapor deposition mode; the Si doping concentration of the first buffer layer 21 was 1E19cm -3, as shown in FIG. 3 (secondary ion mass spectrum, abscissa is thickness, unit nm, and ordinate is atomic number of 1cm 3, unit atoms/cm 3).
Specifically, the nitriding process is as follows: the substrate 10 was placed in a reaction chamber of an MOCVD apparatus, 5000sccm of hydrogen gas and 500sccm of ammonia gas were simultaneously introduced into the reaction chamber for 10 minutes at 1400 c, and thereafter, the introduction of ammonia gas was stopped, and 100sccm of SiH 4 gas was introduced.
S20, cooling the sapphire substrate 10 containing the first buffer layer 21 to 1300 ℃ by using MOCVD equipment, and growing a second buffer layer 22 on the first buffer layer 21, wherein the thickness of the second buffer layer 22 is 1500nm, and the material is an entire layer of unintentionally doped AlN material.
S30, cooling the sapphire substrate 10 containing the first buffer layer 21 to 1250 ℃ by using MOCVD equipment, and growing a third buffer layer 23 on the second buffer layer 22, wherein the thickness of the third buffer layer 23 is 1000nm, and the material is an entire layer of Si-doped AlN material; the doping concentration of the third buffer layer 23 was 8E17cm -3 as shown in FIG. 4 (the secondary ion mass spectrum, the abscissa is thickness in nm, and the ordinate is atomic number of 1cm 3 in atoms/cm 3).
S40, cooling the sapphire substrate 10 containing the first buffer layer 21 to 1100 ℃ by using MOCVD equipment, and growing a fourth buffer layer 24 on the third buffer layer 23, wherein the thickness of the fourth buffer layer 24 is 300nm, the material is a whole layer of Si doped AlGaN material, and the content of Al components is 75%; the doping concentration of the fourth buffer layer 24 was 3E17cm -3 as shown in FIG. 5 (the secondary ion mass spectrum, the abscissa is thickness in nm, and the ordinate is atomic number of 1cm 3 in atoms/cm 3).
And S50, maintaining the growth temperature unchanged, epitaxially growing a fifth buffer layer 25 on the fourth buffer layer 24, wherein the thickness of the fifth buffer layer 25 is 500nm, the material is an integral layer of unintentionally doped AlGaN material, and the Al component content is 60%.
And S60, epitaxially growing an electron injection layer 30 on the fifth buffer layer 25 at a constant growth temperature, wherein the thickness of the electron injection layer 30 is 2500nm, the material is a whole layer of Si-doped AlGaN material, the Al component content is 50%, and the Si doping concentration is 1E20cm -3.
Further, XRD (i.e., X-ray diffraction) analysis was performed on the electron injection layer 30 for a deep ultraviolet light emitting diode prepared in comparative example and example 3 of the present invention, respectively, and the results are shown in table 1:
Table 1 results of rocking curve test of high resolution X-ray diffractometer
As is clear from Table 1, the half widths of the (002) plane and (102) plane rocking curves of the comparative example were 348/524arcsec, respectively, and the half widths of the (002) plane and (102) plane rocking curves of the present invention example were 179/358arcsec, respectively.
From the above results, it is clear that the half-width reduction of the (102) plane rocking curve of the AlGaN material film for the electron injection layer 30 grown in the embodiment of the present invention is more remarkable than that of the (102) plane rocking curve in the comparative example. The half-width of the (102) plane rocking curve has a larger correlation with the edge dislocation density in the material, and the lower the value of the half-width is, the lower the edge dislocation density in the material is, which is helpful to the improvement of the quantum efficiency of the deep ultraviolet light emitting diode;
Meanwhile, the (002) plane rocking curve represents screw dislocation, and the half-width of the (002) plane rocking curve of the AlGaN material film for the electron injection layer 30 grown in the embodiment of the invention is obviously reduced compared with the half-width of the (002) plane rocking curve in the comparative example, which indicates that the AlGaN material film for the electron injection layer 30 grown in the embodiment of the invention has flat surface, no crack and higher growth quality.
Correspondingly, the invention also provides the electron injection layer 30 for the deep ultraviolet light emitting diode, which is prepared by adopting the preparation method of any one of the electron injection layers 30 for the deep ultraviolet light emitting diode.
Further, the invention also provides an epitaxial wafer which contains the electron injection layer 30 for the deep ultraviolet light emitting diode. Preferably, the epitaxial wafer is obtained by sequentially growing an N-type ohmic contact layer, a multiple quantum well active region, a P-type electron blocking layer, and a P-type ohmic contact layer on the electron injection layer 30 for a deep ultraviolet light emitting diode.
The AlGaN material film for the electron injection layer 30 prepared by the invention has high crystal quality and no surface crack, so that the epitaxial wafer obtained on the basis of the invention has more usable area, thereby having high yield and higher brightness.
In summary, the present invention provides a method for preparing an electron injection layer 30 for a deep ultraviolet light emitting diode, which comprises the following steps: firstly, nitriding a substrate 10, secondly, epitaxially growing a first buffer layer 21 on the substrate 10, thirdly, epitaxially growing a second buffer layer 22 on the first buffer layer 21, thirdly, epitaxially growing a third buffer layer 23 on the second buffer layer 22, thirdly, epitaxially growing a fourth buffer layer 24 on the third buffer layer 23, thirdly, epitaxially growing a fifth buffer layer 25 on the fourth buffer layer 24, and finally, epitaxially growing an electron injection layer 30 on the fifth buffer layer 25, wherein the first buffer layer 21 and the third buffer layer 23 are both Si-doped AlN materials, and the second buffer layer 22 is an unintentionally doped AlN material; the fourth buffer layer 24 and the electron injection layer 30 are both Si-doped AlGaN materials, and the fifth buffer layer 25 is an unintentionally doped AlGaN material; according to the preparation method, firstly, the interface between the AlN material and the substrate 10 is subjected to nitriding treatment, and meanwhile, the AlN material and the AlGaN material are respectively subjected to interval Si doping treatment, so that the compressive stress born by the electron injection layer 30 can be reduced, the crystal quality of the electron injection layer 30 is improved, the surface morphology of the electron injection layer 30 is further improved, and finally the luminous efficiency of the deep ultraviolet light-emitting diode is improved.
It should be noted that, the foregoing embodiments all belong to the same inventive concept, and the descriptions of the embodiments have emphasis, and where the descriptions of the individual embodiments are not exhaustive, reference may be made to the descriptions of the other embodiments.
The foregoing examples merely illustrate embodiments of the invention and are described in more detail and are not to be construed as limiting the scope of the invention. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the invention, which are all within the scope of the invention. Accordingly, the scope of protection of the present invention is to be determined by the appended claims.
Claims (10)
1. A method for preparing an electron injection layer for a deep ultraviolet light emitting diode, comprising the steps of:
s10, nitriding a substrate;
s20, epitaxially growing a first buffer layer on the substrate;
S30, epitaxially growing a second buffer layer on the first buffer layer;
s40, epitaxially growing a third buffer layer on the second buffer layer;
s50, epitaxially growing a fourth buffer layer on the third buffer layer;
S60, epitaxially growing a fifth buffer layer on the fourth buffer layer;
s70, epitaxially growing an electron injection layer on the fifth buffer layer;
Wherein the first buffer layer and the third buffer layer are both Si-doped AlN materials, and the second buffer layer is an unintentionally doped AlN material; the fourth buffer layer and the electron injection layer are both made of Si-doped AlGaN materials, and the fifth buffer layer is made of unintentionally-doped AlGaN materials.
2. The method for preparing an electron injection layer for a deep ultraviolet light emitting diode according to claim 1, wherein the step S10 specifically comprises:
s101, placing the substrate in a reaction cavity of MOCVD equipment;
S102, introducing hydrogen and ammonia into the reaction cavity, wherein the flux of the ammonia and the hydrogen is 1:1-1:20, the introducing time is 1-20 min, and the temperature of the reaction cavity is 1100-1500 ℃;
S103, stopping introducing ammonia gas, and introducing SiH 4 gas, wherein the flux of SiH 4 gas and hydrogen gas is 1:5-1:100.
3. The method for preparing an electron injection layer for a deep ultraviolet light emitting diode according to claim 1, wherein the first buffer layer is prepared by in-situ growth or physical vapor deposition.
4. The method for preparing an electron injection layer for a deep ultraviolet light emitting diode according to claim 1, wherein the thickness of the first buffer layer is 5nm to 30nm, and the Si doping concentration of the first buffer layer is 1E19cm -3～1E21cm-3.
5. The method for preparing an electron injection layer for a deep ultraviolet light emitting diode according to claim 1, wherein the thickness of the second buffer layer is 500nm to 3000nm.
6. The method of claim 5, wherein the second buffer layer has a surface roughness of less than or equal to 2nm in a 10 μm region.
7. The method for preparing an electron injection layer for a deep ultraviolet light emitting diode according to claim 1, wherein the thickness of the third buffer layer is 100nm to 2000nm, and the Si doping concentration of the third buffer layer is 1E17cm -3～1E19cm-3.
8. The method for manufacturing an electron injection layer for a deep ultraviolet light emitting diode according to claim 1, wherein a growth temperature of the third buffer layer is less than or equal to a growth temperature of the second buffer layer.
9. The method for preparing an electron injection layer for a deep ultraviolet light emitting diode according to claim 1, wherein the thickness of the fourth buffer layer is 100nm to 1000nm, and the Si doping concentration of the fourth buffer layer is 1E17cm -3～1E19cm-3; the thickness of the fifth buffer layer is 100 nm-2000nm.
10. The method for manufacturing an electron injection layer for a deep ultraviolet light emitting diode according to claim 9, wherein the fourth buffer layer has an Al composition of x, the fifth buffer layer has an Al composition of y, and the electron injection layer has an Al composition of z;
Wherein the relationship between x, y and z is as follows: and z is less than or equal to y is less than or equal to x is less than or equal to (y+100%)/2.
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