Preparation method of nitride template, nitride template and semiconductor device

Abstract

The invention discloses a preparation method of a nitride template, the nitride template and a semiconductor device. The method comprises the following steps: providing a heterogeneous substrate required by a template layer for growing a target III-nitride; sequentially growing a nucleating layer, a buffer layer of a target III-group nitride and a first N-type layer of the target III-group nitride on the heterogeneous substrate to obtain a first epitaxial structure; preprocessing the first epitaxial structure to convert the first N-type layer into a second N-type layer with multiple pores inside to obtain a second epitaxial structure; the multiple pores are located in the pore layer of the second N-type layer; sequentially growing a dislocation inhibition layer and a template layer of a target III-group nitride on the second epitaxial structure to obtain a third epitaxial structure; stripping the third epitaxial structure along the pore layer to obtain a nitride template; the nitride template comprises at least part of a second N-type layer, a dislocation inhibition layer and a template layer which are overlapped. When the porous layer relieves stress to grow the thick film, a stress concentration area can be formed in the area, and self-stripping of the thin film is facilitated.

Description

Technical Field

[0001] This invention relates to the field of semiconductor material preparation, and particularly to nitride templates and their preparation methods, as well as semiconductor devices including the nitride templates. Background Technology

[0002] Group II nitrides possess advantages such as good chemical stability, excellent thermal conductivity, high breakdown voltage, and low dielectric constant, making them widely used in devices such as ultraviolet light-emitting diodes, ultraviolet photodetectors, optical frequency combs, and acoustic filters. They are among the most promising types of semiconductor materials. Using a homogeneous substrate is an ideal choice for obtaining high-quality semiconductor materials.

[0003] However, large-size homogeneous substrates are currently lacking, so templates consisting of heterogeneous substrates and epitaxial layers of group III nitrides (such as gallium nitride) grown on them are commonly used to fabricate group III nitride semiconductor materials. Due to the significant thermal and lattice mismatch between group III nitrides and the heterogeneous substrate, the group III nitride epitaxial layers grown on the heterogeneous substrate are prone to high-density dislocation defects and residual strain. This makes it difficult to achieve low defect density (less than 10⁻⁶) in gallium nitride heteroepitaxy. 7 cm -2 The production of gallium nitride (GaN) materials is extremely difficult because the dislocation lines are almost perpendicular, so it is usually necessary to grow very thick materials (greater than 500 micrometers) to achieve dislocation annihilation. However, heteroepitaxial materials often have high internal stress, causing the materials to crack before they reach a sufficient thickness.

[0004] The present invention solves at least one of the above problems. Summary of the Invention

[0005] The purpose of this invention is to provide a method for preparing nitride templates, nitride templates, and semiconductor devices, to solve the problem that in the prior art, it is usually necessary to grow very thick (greater than 500 micrometers) nitride templates to achieve dislocation annihilation. However, heteroepitaxial materials usually have large internal stress, which causes the materials to crack when they grow to a very thick thickness. The nitride templates prepared by this invention can achieve dislocation annihilation without growing to a very thick thickness, ensuring the crystal quality of the grown thin film nitride templates.

[0006] To achieve the above objectives, a first aspect of the present invention provides a method for preparing a nitride template, comprising the following steps:

[0007] Provide a heterogeneous substrate required for growing a template layer containing the target group III nitride;

[0008] A first epitaxial structure is obtained by sequentially stacking and growing a core layer, a buffer layer containing the target group III nitride, and a first N-type layer containing the target group III nitride on the heterostructure substrate.

[0009] The first epitaxial structure is preprocessed to transform the first N-type layer into a second N-type layer with multiple pores inside, thereby obtaining a second epitaxial structure; wherein, the second N-type layer includes a porous layer, and the multiple pores are located within the porous layer;

[0010] A misalignment suppression layer and a template layer containing the target group III nitride are sequentially grown on the second epitaxial structure to obtain a third epitaxial structure.

[0011] The third epitaxial structure is peeled off along the porous layer to obtain a nitride template; wherein the nitride template includes at least a portion of a second N-type layer, the misalignment suppression layer, and the template layer stacked together.

[0012] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention reduces thermal and lattice mismatch between the heterogeneous substrate and the target group III nitride (e.g., GaN) by pre-growing a nucleation layer on the heterogeneous substrate, effectively reducing dislocations and strain, and improving crystal quality; by pre-growing a buffer layer of the target group III nitride as a transition layer on the nucleation layer, the stress caused by the property difference between the heterogeneous substrate and GaN can be alleviated, thereby reducing the defect density in the template layer and realizing the transition from the heterogeneous substrate to the growth of GaN epitaxial material; by pre-treating the first N-type conductive layer to be porous, a second N-type layer with multiple pores is obtained, which can greatly reduce the internal stress of the template layer of the subsequently grown GaN material while ensuring crystal quality; by covering the porous second N-type layer with a dislocation suppression layer, the dislocation growth caused by the group III nitride material in the template layer during pre-treatment can be overcome, the dislocations of secondary growth can be suppressed, and the crystal quality can be further improved.

[0013] This invention obtains a second N-type layer with multiple pores (pore layer) by porous treatment of the first N-type layer. While the pore layer relieves stress and allows for the growth of a thick film (template layer), a stress concentration area will eventually form in the pore layer region, which is beneficial to the self-peeling of the final film (nitride template).

[0014] In some feasible embodiments of the first aspect, a first epitaxial structure is obtained by sequentially stacking and growing a core layer, a buffer layer containing the target group III nitride, and a first N-type layer containing the target group III nitride on the heterostructure substrate, comprising:

[0015] Under the conditions of magnetron sputtering pressure of 2-6 mtorr, magnetron sputtering power of 3-5 kW, and magnetron sputtering time of 300-600 s, the nucleation layer with a thickness of 10-30 nm is grown by magnetron sputtering on the heterogeneous substrate.

[0016] The buffer layer is grown on the nucleation layer;

[0017] Under the conditions of a growth temperature of 1050–1100℃, a growth pressure of 150–250 torr, and a molar flow rate of TMGa growth source of 50–200 μmol / min, a first N-type layer with a thickness of 500–2000 nm is epitaxially grown on the buffer layer to obtain the first epitaxial structure:

[0018] And / or, the target group III nitride includes at least one of aluminum nitride or gallium nitride; and / or, the material of the nucleation layer is a group III nitride.

[0019] In some feasible embodiments of the first aspect, growing the buffer layer includes:

[0020] Under the conditions of growth temperature of 900-1100℃, growth pressure of 200-500 torr, and molar flow rate of TMGa growth source of 10-100 μmol / min, the buffer layer with a thickness of 100-3000 nm is epitaxially grown on the nucleation layer.

[0021] Alternatively, the buffer layer comprises an AlGaN layer and a target group III nitride layer grown sequentially; growing the buffer layer includes:

[0022] Under the conditions of growth temperature of 950-1200℃, growth pressure of 30-50 torr, and growth source TMAl / TMGa molar flow ratio of 25%-75%, an AlGaN layer with a thickness of 10-50 nm is epitaxially grown on the nucleation layer.

[0023] Under the conditions of growth temperature of 850–950℃, growth pressure of 40–60 torr, and molar flow rate of growth source TMGa of 5–200 μmol / min, the target group III nitride layer with a thickness of 400–600 nm is epitaxially grown on the AlGaN layer.

[0024] In some feasible embodiments of the first aspect, preprocessing the first epitaxial structure includes:

[0025] The first epitaxial structure is removed from the reaction chamber, and under the conditions of corrosion voltage of 10-30V and corrosion time of 1-10min, the first N-type layer of the first epitaxial structure is subjected to electrochemical corrosion treatment to transform the first N-type layer into a second N-type layer with multiple pores inside.

[0026] In some feasible embodiments of the first aspect, the second N-type layer further includes a first sub-N-type layer and a second sub-N-type layer, wherein the first sub-N-type layer, the porous layer and the second sub-N-type layer are stacked sequentially, the first sub-N-type layer is located between the porous layer and the buffer layer, and the second sub-N-type layer is disposed between the porous layer and the misalignment suppression layer.

[0027] In some feasible embodiments of the first aspect, the porosity of the pore layer is 1% to 20%; and / or, the pore size of each pore is 100 to 1000 nm.

[0028] In some feasible embodiments of the first aspect, the doping element in the first N-type layer includes at least Si / Ge, and the doping concentration of the doping element is 1E18 to 1E20 cm⁻¹. -3 .

[0029] In some feasible embodiments of the first aspect, the material of the dislocation suppression layer comprises at least silicon nitride; and / or, growing the dislocation suppression layer on the second epitaxial structure comprises:

[0030] The second epitaxial structure is placed in the reaction chamber; under the conditions of growth temperature of 900-1000℃, growth pressure of 100-200 torr, and molar flow rate of growth source SiH4 of 100-1000 sccm, a dislocation suppression layer with a thickness of 1-10 nm is grown on the second N-type layer.

[0031] And / or, growing a template layer containing the target group III nitride includes:

[0032] Under the conditions of growth temperature of 950–1050℃, growth pressure of 500–760 torr, and molar flow rate of GaCl growth source of 10–100 μmol / min, a template layer with a thickness of 50–500 μm is grown on the dislocation suppression layer.

[0033] In a second aspect, the present invention provides a nitride template, which is prepared using the preparation method described in the present invention.

[0034] A third aspect of the present invention provides a semiconductor device comprising a nitride template prepared by the preparation method described herein. Attached Figure Description

[0035] Figure 1 A flowchart illustrating the structural changes of the nitride template provided by this invention during the preparation process;

[0036] Figure 2 This is a schematic diagram of the structure of the nitride template provided by the present invention;

[0037] Figure 3 This is a flowchart illustrating the steps of the nitride template preparation method according to an embodiment of the present invention.

[0038] In the figure: 10, first epitaxial structure; 11, heterogeneous substrate; 12, nucleation layer; 13, buffer layer;

[0039] 14. First N-type layer; 15. Second N-type layer; 151. First sub-N-type layer; 152. Porous layer;

[0040] 153. Second sub-N-type layer; 16. Dislocation suppression layer; 17. Template layer; 20. Second epitaxial structure;

[0041] 30. Third epitaxial structure; 40. Nitride template. Detailed Implementation

[0042] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, they are provided to make the invention more comprehensive and complete, and to fully convey the concept of the exemplary embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar structures, and therefore repeated descriptions of them will be omitted.

[0043] The terms used to express position and direction in this invention are illustrated with reference to the accompanying drawings, but changes can be made as needed, and all such changes are included within the scope of protection of this invention.

[0044] Combined with appendix Figures 1 to 3 As shown, in a first aspect, the present invention provides a method for preparing a nitride template, the method comprising the following steps S1-S5.

[0045] Step S1: As Figure 1 As shown in (a), a heterogeneous substrate 11 is provided for growing a template layer 17 containing a target group III nitride.

[0046] The present invention does not specifically limit the target group III nitride; any suitable group III nitride in the art can be used to implement the technical solution of the present invention. In some embodiments of the present invention, the target group III nitride may be GaN, AlN, AlGaN, InGaN, or AlInGaN, preferably GaN.

[0047] The present invention does not particularly limit the heterogeneous substrate 11; any suitable heterogeneous substrate 11 in the art can be used to implement the technical solution of the present invention. In some embodiments of the present invention, the heterogeneous substrate 11 used can be selected from sapphire substrates, silicon carbide substrates, or metal substrates, preferably sapphire substrates. The metal substrate can be a high-temperature resistant metal such as molybdenum or titanium.

[0048] Step S2: As Figure 1 (a) - such as Figure 1 As shown in (c), a core layer 12, a buffer layer 13 containing a target group III nitride, and a first N-type layer 14 containing a target group III nitride are sequentially stacked and grown on a heterogeneous substrate 11 to obtain a first epitaxial structure 10.

[0049] Due to the significant thermal and lattice mismatch between the heterostructure 11 and the group III nitride, forming the template layer 17 directly on the heterostructure 11 easily leads to high-density dislocation defects and residual strain. The inventors discovered that by pre-forming a nucleation layer 12 of a certain thickness on the heterostructure 11, dislocations and strain can be effectively reduced, thereby improving the quality of the crystal.

[0050] Furthermore, the material of the nucleation layer 12 is a group III nitride. This invention does not specifically limit the use of group III nitrides; any suitable group III nitride in the art can be used to implement the technical solution of this invention. In some embodiments of this invention, the group III nitride can be GaN, AlN, AlGaN, InGaN, or AlInGaN, preferably AlN.

[0051] Furthermore, through in-depth research and exploration, the inventors discovered that when the nucleation layer 12 is formed under the following conditions, the lattice transition and stress buffering effects between the heterogeneous substrate 11 and the epitaxial layer can be well achieved.

[0052] In a preferred embodiment of the present invention, step S2 includes steps S21-S23.

[0053] Step S21: Under the conditions of magnetron sputtering pressure of 2-6 mtorr, magnetron sputtering power of 3-5 kW, and magnetron sputtering time of 300-600 s, a nucleation layer 12 with a thickness of 10-30 nm is grown by magnetron sputtering on the heterogeneous substrate 11, as follows: Figure 1 As shown in (a).

[0054] The growth thickness of the nucleation layer 12 can be 10 nm, 15 nm, 20 nm, 25 nm or 30 nm.

[0055] For example, the magnetron sputtering pressure can be 2.0 mtorr, 2.4 mtorr, 2.8 mtorr, 3.2 mtorr, 3.6 mtorr, 4.0 mtorr, 4.4 mtorr, 4.8 mtorr, 5.2 mtorr, 5.6 mtorr, or 6.0 mtorr; the magnetron sputtering power can be 3 kW, 3.2 kW, 3.4 kW, 3.6 kW, 3.8 kW, 4 kW, 4.2 kW, 4.4 kW, 4.6 kW, 4.8 kW, or 5 kW; and the magnetron sputtering time can be 300 s, 330 s, 360 s, 390 s, 420 s, 450 s, 480 s, 510 s, 540 s, 570 s, or 600 s.

[0056] It should be further noted that when the growth thickness is greater than 30 nm, the magnetron sputtering pressure is greater than 6 mtorr, the magnetron sputtering power is greater than 5 kW, or the magnetron sputtering time is greater than 600 s, it will cause adverse effects such as a decrease in the quality of the nucleation layer 12 and insufficient material density; when the growth thickness is less than 10 nm, the magnetron sputtering pressure is less than 2 mtorr, the magnetron sputtering power is less than 3 kW, or the magnetron sputtering time is less than 300 s, it will cause adverse effects such as uneven and discontinuous film surface of the nucleation layer 12.

[0057] Step S22: As Figure 1 As shown in (b), a buffer layer 13 is grown on the nucleation layer 12.

[0058] During the epitaxial growth of the template layer 17 of the target group III nitride GaN on the heterogeneous substrate 11, the difference in lattice constant and thermal expansion coefficient between the substrate material and GaN leads to a large stress and defect density in the template layer 17. These stresses and defects severely affect the quality and performance of the crystal. This invention alleviates the stress caused by the property difference between the heterogeneous substrate 11 and GaN by pre-growing a buffer layer 13 on the nucleation layer 12 as a transition layer and making the material of the buffer layer 13 consistent with that of the template layer 17. This reduces the defect density in the template layer 17 and achieves the transition from the heterogeneous substrate 11 to the growth of GaN epitaxial material.

[0059] Furthermore, through in-depth research and exploration, the inventors discovered that when the buffer layer 13 is formed under the following conditions, the crystal quality and surface morphology of the epitaxial buffer layer 13 can be further improved, laying the foundation for the subsequent growth of the high-quality GaN template layer 17.

[0060] As a preferred embodiment of step S22, step S22 includes step S22a.

[0061] Step S22a: Under the conditions of growth temperature of 900-1100℃, growth pressure of 200-500 torr, and molar flow rate of growth source TMGa of 10-100 μmol / min, a buffer layer 13 with a thickness of 100-3000 nm is epitaxially grown on nucleation layer 12.

[0062] The material of the buffer layer 13 can be GaN or AlN, preferably GaN; the growth thickness of the buffer layer 13 can be 100nm, 500nm, 1000nm, 1500nm, 2000nm, 2500nm or 3000nm.

[0063] For example, the growth temperature can be 900℃, 950℃, 1000℃, 1050℃ or 1100℃; the growth pressure can be 200 torr, 250 torr, 300 torr, 350 torr, 400 torr, 450 torr or 500 torr; and the molar flow rate of the growth source TMGa can be 10 μmol / min, 20 μmol / min, 30 μmol / min, 40 μmol / min, 50 μmol / min, 60 μmol / min, 70 μmol / min, 80 μmol / min, 90 μmol / min or 100 μmol / min.

[0064] It should be noted that when the growth thickness is greater than 3000 nm, the growth pressure is greater than 500 torr, the growth temperature is greater than 1100℃, or the molar flow rate of the growth source TMGa is greater than 100 μmol / min, it will cause adverse effects such as poor material uniformity and rough surface morphology. When the growth thickness is less than 100 nm, the growth pressure is less than 200 torr, the growth temperature is less than 900℃, or the molar flow rate of the growth source TMGa is less than 10 μmol / min, it will cause adverse effects such as poor material crystal quality and dislocation proliferation.

[0065] As another preferred embodiment of step S22, the buffer layer 13 includes an AlGaN layer and a target group III nitride layer grown sequentially.

[0066] The buffer layer made of AlGaN / target group III nitride material serves to block through dislocations, thereby reducing dislocations and improving crystal quality.

[0067] The growth buffer layer 13 includes step S22b, which includes:

[0068] (1) Under the conditions of growth temperature of 950-1200℃, growth pressure of 30-50 torr and growth source TMAl / TMGa molar flow ratio of 25%-75%, an AlGaN layer with a thickness of 10-50 nm is epitaxially grown on nucleation layer 12.

[0069] The growth thickness of the AlGaN layer can be 10nm, 15nm, 20nm, 25nm, 30nm, 35nm, 40nm, 45nm, or 50nm.

[0070] For example, the growth temperature can be 950℃, 1000℃, 1050℃, 1100℃, 1150℃ or 1200℃, and the growth pressure can be 30 torr, 32 torr, 35 torr, 38 torr, 40 torr, 42 torr, 45 torr, 48 torr or 50 torr; the molar flow ratio of the growth source TMAl / TMGa can be 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70% or 75%.

[0071] It should be noted that when the growth thickness is greater than 50 nm, the growth pressure is greater than 50 torr, the growth temperature is greater than 1200℃, or the molar flow rate ratio of the growth source TMAl / TMGa is greater than 75%, it will cause adverse effects such as strong pre-reaction and poor lattice merging; when the growth thickness is less than 10 nm, the growth pressure is less than 30 torr, the growth temperature is less than 950℃, or the molar flow rate ratio of the growth source TMAl / TMGa is less than 25%, it will cause adverse effects such as insufficient reaction and decreased crystal quality.

[0072] (2) Under the conditions of growth temperature of 850-950℃, growth pressure of 40-60 torr and growth source TMGa molar flow rate of 5-200 μmol / min, a target group III nitride layer with a thickness of 400-600 nm was epitaxially grown on the AlGaN layer.

[0073] The material of the target group III nitride layer can be GaN or AlN, preferably GaN; the growth thickness of the target group III nitride layer can be 400nm, 420nm, 450nm, 480nm, 500nm, 520nm, 550nm, 580nm or 600nm.

[0074] For example, the growth temperature can be 850℃, 860℃, 870℃, 880℃, 890℃, 900℃, 910℃, 920℃, 930℃, 940℃ or 950℃; the growth pressure can be 40 torr, 42 torr, 45 torr, 48 torr, 50 torr, 52 torr, 55 torr, 58 torr or 60 torr; the molar flow rate of the growth source TMGa can be 5 μmol / min, 10 μmol / min, 20 μmol / min, 40 μmol / min, 60 μmol / min, 80 μmol / min, 100 μmol / min, 150 μmol / min, 180 μmol / min or 200 μmol / min.

[0075] It should be noted that when the growth thickness is greater than 600 nm, the growth pressure is greater than 60 torr, the growth temperature is greater than 950℃, or the molar flow rate of the growth source TMGa is greater than 200 μmol / min, it will cause adverse effects such as excessive growth of two-dimensional materials and the risk of pores in the material system. When the growth thickness is less than 400 nm, the growth pressure is less than 40 torr, the growth temperature is less than 850℃, or the molar flow rate of the growth source TMGa is less than 5 μmol / min, it will cause adverse effects such as excessive growth of three-dimensional materials and insufficient surface smoothness of the material.

[0076] Step S23: Under the conditions of growth temperature of 1050-1100℃, growth pressure of 150-250 torr, and molar flow rate of TMGa growth source of 50-200 μmol / min, a first N-type layer 14 with a thickness of 500-2000 nm is epitaxially grown on the buffer layer 13 to obtain the first epitaxial structure 10, as shown below. Figure 1 As shown in (c).

[0077] The material of the first N-type layer 14 can be GaN or AlN, preferably GaN; the growth thickness of the first N-type layer 14 can be 500nm, 600nm, 700nm, 800nm, 900nm, 1000nm, 1100nm, 1200nm, 1300nm, 1400nm, 1500nm, 1600nm, 1700nm, 1800nm, 1900nm or 2000nm.

[0078] For example, the growth temperature can be 1050℃, 1060℃, 1070℃, 1080℃, 1090℃ or 1100℃; the growth pressure can be 150 torr, 160 torr, 170 torr, 180 torr, 190 torr, 200 torr, 210 torr, 220 torr, 230 torr, 240 torr or 250 torr; the molar flow rate of the growth source TMGa can be 50 μmol / min, 60 μmol / min, 70 μmol / min, 80 μmol / min, 90 μmol / min, 100 μmol / min, 110 μmol / min, 120 μmol / min, 130 μmol / min, 140 μmol / min, 150 μmol / min, 160 μmol / min, 170 μmol / min, 180 μmol / min, 190 μmol / min or 200 μmol / min.

[0079] It should be noted that when the growth thickness is greater than 2000 nm, the growth pressure is greater than 250 torr, the growth temperature is greater than 1100℃, or the molar flow rate of TMGa is greater than 200 μmol / min, the surface of the grown GaN material will not be smooth enough and the crystal quality will not be good enough. When the growth thickness is less than 500 nm, the growth pressure is less than 150 torr, the growth temperature is less than 1050℃, or the molar flow rate of TMGa is less than 50 μmol / min, the crystal quality will be reduced and there will be more dislocations.

[0080] Step S3: Preprocess the first epitaxial structure 10 to transform the first N-type layer 14 into a second N-type layer 15 with multiple internal pores, thus obtaining the second epitaxial structure 20, as shown below. Figure 1 As shown in (d).

[0081] It should be noted that the material of the first N-type layer 14 is the same as that of the second N-type layer 15. The second N-type layer 15 includes a porous layer 152, and multiple pores are located within the porous layer 152.

[0082] While traditional gallium nitride (GaN) materials grown by sputtering aluminum nitride onto sapphire substrates can achieve crystal quality of (002) < 100 arcsec and (102) < 200 arcsec, epitaxial layer cracking inevitably occurs due to stress when the thickness exceeds approximately 50 μm. This invention addresses this by porousening the first conductive N-type layer 14 to obtain a second N-type layer 15 with multiple pores. The porous layer 152 within the second N-type layer 15 can significantly reduce the internal stress of the template layer 17 for the subsequently grown target group III nitride (e.g., GaN material) while ensuring crystal quality. This is because porousification reduces the internal density of the GaN material, allowing the residual stress caused by lattice mismatch to be fully released without significantly affecting the overall quality.

[0083] In a preferred embodiment of the present invention, the first epitaxial structure 10 is taken out from the reaction chamber, and the first N-type layer 14 of the first epitaxial structure 10 is subjected to electrochemical corrosion treatment under the conditions of corrosion voltage of 10-30V and corrosion time of 1-10min, so that the first N-type layer 14 is transformed into a second N-type layer 15 with multiple pores inside, thereby obtaining the second epitaxial structure 20.

[0084] For example, the corrosion voltage can be 10V, 12V, 15V, 18V, 20V, 22V, 25V, 28V or 30V; the corrosion time can be 1min, 2min, 3min, 4min, 5min, 6min, 7min, 8min, 9min or 10min.

[0085] It should be noted that when the corrosion voltage is greater than 30V or the corrosion time is greater than 10min, it will cause excessive corrosion, which will lead to a rapid decline in the overall quality of the material and an increase in surface porosity. When the corrosion voltage is less than 10V or the corrosion time is less than 1min, it will reduce the corrosion effect and have a poor effect on porosity control.

[0086] The purpose of this implementation method is to reduce the density and residual stress of lattice mismatch of the material by electrochemical corrosion without affecting the quality of the material crystals. At the same time, the overall quality of the material, except for the surface, will not be greatly affected.

[0087] Furthermore, in some specific embodiments, the porosity of the porous layer 152 is 1% to 20%, for example, the porosity can be 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19% or 20%.

[0088] Porosity within this range has the technical effect of relieving and releasing residual stress within the crystal without affecting the overall material and surface quality and morphology. Porosity greater than 20% will cause a sharp decline in the quality of the material crystal and adverse effects such as the appearance of large corrosion pits on the surface; porosity less than 1% will prevent the release of internal stress caused by lattice mismatch.

[0089] Furthermore, in some specific embodiments, the pore size of each pore is 100 to 1000 nm. For example, the pore size can be 100 nm, 200 nm, 300 nm, 400 nm, 500 nm, 600 nm, 700 nm, 800 nm, 900 nm or 1000 nm.

[0090] The pore size within this range has the technical effect of relieving residual stress under lattice mismatch. A pore size greater than 1000 nm will cause excessive voids inside the material, leading to dislocation proliferation and thus affecting the overall quality of the material; a pore size less than 100 nm cannot form an effective stress release effect.

[0091] Regarding the second N-type layer 15, it needs further explanation that, as Figure 1 As shown in (d), the second N-type layer 15 further includes a first sub-N-type layer 151 and a second sub-N-type layer 153. The first sub-N-type layer 151, the porous layer 152 and the second sub-N-type layer 153 are stacked sequentially. The first sub-N-type layer 151 is located between the porous layer 152 and the buffer layer 13, and the second sub-N-type layer 153 is located between the porous layer 152 and the subsequently grown misalignment suppression layer 16.

[0092] Furthermore, in a preferred embodiment of the present invention, the doping elements in the first N-type layer 14 include at least Si / Ge, and the doping concentration of the doping elements is 1E18 to 1E20 cm⁻¹. -3 The main function of doping Si and Ge is to form electrical conductivity, thus completing the electrochemical corrosion. If the doping concentration is too low (i.e., less than 1E¹⁸ cm⁻¹), the corrosion will be compromised. -3 If the doping level is too high (i.e., greater than 1E20cm), the current will not easily pass through this area, thus preventing corrosion of the material; -3 When impurities are excessive, the quality of the material will drop sharply.

[0093] Step S4: As Figure 1 (e)- Figure 1 As shown in (f), a dislocation suppression layer 16 and a template layer 17 containing the target group III nitride are sequentially grown on the second epitaxial structure 20 to obtain the third epitaxial structure 30.

[0094] Since electrochemical corrosion may cause dislocation growth in the target group III nitride material of template layer 17, which may then penetrate to the surface, covering the porous second N-type layer 15 with a growth dislocation inhibition layer 16 can block dislocations and inhibit secondary growth of dislocations, thereby further ensuring and improving crystal quality.

[0095] Furthermore, through in-depth research, the inventors discovered that by growing the dislocation suppression layer 16 under the following conditions, target group III nitrides such as gallium nitride can be directly grown in thick films with low stress and low defects. This achieves a final dislocation density of up to 10-1 as the thickness increases with the continuous annihilation of the dislocation as the thickness increases to a depth of 500 μm. 6 cm -2 The magnitude of the effect.

[0096] In a preferred embodiment of the present invention, step S4 includes steps S41-S42.

[0097] Step S41: Place the second epitaxial structure 20 into the reaction chamber, and grow a dislocation suppression layer 16 with a thickness of 1-10 nm on the second N-type layer 15 (specifically the second sub-N-type layer 153) under the conditions of growth temperature of 900-1000℃, growth pressure of 100-200 torr, and molar flow rate of growth source SiH4 of 100-1000 sccm.

[0098] The material of the dislocation suppression layer 16 can be SiN, AlN or AlGaN, preferably SiN; the growth thickness of the dislocation suppression layer 16 is 1nm, 2nm, 3nm, 4nm, 5nm, 6nm, 7nm, 8nm, 9nm or 10nm.

[0099] It should be noted that when the growth temperature is greater than 1000℃, the growth pressure is greater than 200 torr, or the molar flow rate of the growth source SiH4 is greater than 1000 sccm, it will cause an excess of Si and a decrease in the quality of SiN material. When the growth temperature is less than 900℃, the growth pressure is less than 100 torr, or the molar flow rate of the growth source SiH4 is less than 100 sccm, it will cause difficulties in SiN material film formation.

[0100] Step S42: Under the conditions of growth temperature of 950-1050℃, growth pressure of 500-760 torr, and molar flow rate of GaCl growth source of 10-100 μmol / min, a template layer 17 with a thickness of 50-500 μm is grown on the dislocation suppression layer 16.

[0101] The growth thickness of template layer 17 can be 50μm, 100μm, 150μm, 200μm, 250μm, 300μm, 350μm, 400μm, 450μm or 500μm.

[0102] It should be noted that when the growth temperature is greater than 1050℃, the growth pressure is greater than 760 torr, or the molar flow rate of the growth source GaCl is greater than 100 μmol / min, the GaN thick film material will grow too fast, which will have the adverse effect of failing to guarantee crystal quality. When the growth temperature is less than 950℃, the growth pressure is less than 500 torr, or the molar flow rate of the growth source GaCl is less than 10 μmol / min, the growth rate will be too slow and the crystal quality will be poor.

[0103] Step S5: The third epitaxial structure 30 is peeled off along the porous layer 152 to obtain... Figure 2 Nitride template 40 is shown.

[0104] It should be noted that the nitride template 40 includes at least a portion of the second sub-N-type layer (preferably the entire second sub-N-type layer 153), the misalignment suppression layer 16, and the template layer 17, which are stacked together.

[0105] By electrochemically etching the first N-type layer 14, a second N-type layer 15 with multiple pores (pore layer 152) is obtained. While the pore layer 153 relieves stress and allows for the growth of a thick film (template layer 17), a stress concentration area will eventually form in the pore layer 153 region, which is conducive to the self-peeling of the final film (nitride template 40).

[0106] In a second aspect, the present invention provides a nitride template, which is prepared by the above-described preparation method.

[0107] A third aspect of the present invention provides a semiconductor device comprising the aforementioned nitride template. This ensures the semiconductor device exhibits high voltage withstand capability and high power density.

[0108] The technical solution of the present invention will be described in more detail below. However, it should be understood that the following embodiments are merely for explaining and illustrating the technical solution, and do not limit the scope of the present invention. Moreover, unless otherwise specified, the various raw materials, reaction equipment, detection equipment, and methods used in the following embodiments are all known in the art.

[0109] Example 1

[0110] This embodiment provides a method for preparing a nitride template, which includes the following steps S1-S5.

[0111] Step S1: Provide a heterogeneous substrate required for growing a template layer containing the target group III nitride.

[0112] The target group III nitride is GaN, and the heterostructure is a sapphire substrate.

[0113] Step S2: A core layer, a buffer layer containing the target group III nitride, and a first N-type layer containing the target group III nitride are sequentially stacked and grown on a heterogeneous substrate to obtain a first epitaxial structure.

[0114] Step S2 includes steps S21-S23.

[0115] Step S21: Under the conditions of magnetron sputtering pressure of 2 mtorr, magnetron sputtering power of 3 kW, and magnetron sputtering time of 300 s, a nucleation layer with a thickness of 10 nm and made of AlN is grown by magnetron sputtering on a heterogeneous substrate.

[0116] Step S22: Under the conditions of growth temperature of 900℃, growth pressure of 200 torr, and molar flow rate of growth source TMGa of 10 μmol / min, a buffer layer with a thickness of 100 nm and made of GaN is epitaxially grown on the nucleation layer.

[0117] Step S23: Under the conditions of growth temperature of 1050℃, growth pressure of 150 torr, and molar flow rate of growth source TMGa of 50 μmol / min, a first N-type layer with a thickness of 500 nm and material of GaN is epitaxially grown on the buffer layer to obtain the first epitaxial structure.

[0118] Step S3: Remove the first epitaxial structure from the reaction chamber. Under the conditions of corrosion voltage of 10V and corrosion time of 1min, perform electrochemical corrosion treatment on the first N-type layer of the first epitaxial structure to transform the first N-type layer into a second N-type layer with multiple pores inside, thereby obtaining the second epitaxial structure.

[0119] The porosity of the porous layer is 1%, and the diameter of each pore is 100 nm.

[0120] Step S4: A dislocation suppression layer and a template layer containing the target group III nitride are sequentially grown on the second epitaxial structure to obtain the third epitaxial structure.

[0121] Step S4 includes steps S41-S42.

[0122] Step S41: Place the second epitaxial structure into the reaction chamber, and grow a dislocation suppression layer with a thickness of 1 nm and made of SiN on the second N-type layer under the conditions of growth temperature of 900℃, growth pressure of 100 torr and molar flow rate of growth source SiH4 of 100 sccm.

[0123] Step S42: Under the conditions of growth temperature of 950℃, growth pressure of 500 torr, and molar flow rate of growth source GaCl of 10 μmol / min, a template layer with a thickness of 50 μm and material of GaN is grown on the dislocation suppression layer.

[0124] Step S5: The third epitaxial structure is peeled off along the pore layer to obtain the nitride template.

[0125] Example 2

[0126] This embodiment provides a method for preparing a nitride template, which includes the following steps S1-S5.

[0127] Step S1: Provide a heterogeneous substrate required for growing a template layer containing the target group III nitride.

[0128] The target group III nitride is GaN, and the heterostructure is a sapphire substrate.

[0129] Step S2: A core layer, a buffer layer containing the target group III nitride, and a first N-type layer containing the target group III nitride are sequentially stacked and grown on a heterogeneous substrate to obtain a first epitaxial structure.

[0130] Step S2 includes steps S21-S23.

[0131] Step S21: Under the conditions of magnetron sputtering pressure of 6 mtorr, magnetron sputtering power of 5 kW, and magnetron sputtering time of 600 s, a nucleation layer with a thickness of 30 nm and material of AlN is grown by magnetron sputtering on a heterogeneous substrate.

[0132] Step S22: Under the conditions of growth temperature of 1100℃, growth pressure of 500 torr, and molar flow rate of growth source TMGa of 100 μmol / min, a buffer layer with a thickness of 3000 nm and made of GaN is epitaxially grown on the nucleation layer.

[0133] Step S23: Under the conditions of growth temperature of 1100℃, growth pressure of 250 torr, and molar flow rate of growth source TMGa of 200 μmol / min, a first N-type layer with a thickness of 2000 nm and made of GaN is epitaxially grown on the buffer layer to obtain the first epitaxial structure.

[0134] Step S3: Remove the first epitaxial structure from the reaction chamber. Under the conditions of corrosion voltage of 30V and corrosion time of 10min, perform electrochemical corrosion treatment on the first N-type layer of the first epitaxial structure to transform the first N-type layer into a second N-type layer with multiple pores inside, thereby obtaining the second epitaxial structure.

[0135] The porosity of the pore layer is 20%, and the diameter of each pore is 1000 nm.

[0136] Step S4: A dislocation suppression layer and a template layer containing the target group III nitride are sequentially grown on the second epitaxial structure to obtain the third epitaxial structure.

[0137] Step S4 includes steps S41-S42.

[0138] Step S41: Place the second epitaxial structure into the reaction chamber, and grow a dislocation suppression layer with a thickness of 10 nm and made of SiN on the second N-type layer under the conditions of growth temperature of 1000℃, growth pressure of 200 torr and molar flow rate of growth source SiH4 of 1000 sccm.

[0139] Step S42: Under the conditions of growth temperature of 1050℃, growth pressure of 760 torr, and molar flow rate of growth source GaCl of 100 μmol / min, a template layer with a thickness of 500 μm and material of GaN is grown on the dislocation suppression layer.

[0140] Step S5: The third epitaxial structure is peeled off along the pore layer to obtain the nitride template.

[0141] Example 3

[0142] This embodiment provides a method for preparing a nitride template, which includes the following steps S1-S5.

[0143] Step S1: Provide a heterogeneous substrate required for growing a template layer containing the target group III nitride.

[0144] The target group III nitride is GaN, and the heterostructure is a sapphire substrate.

[0145] Step S2: A core layer, a buffer layer containing the target group III nitride, and a first N-type layer containing the target group III nitride are sequentially stacked and grown on a heterogeneous substrate to obtain a first epitaxial structure.

[0146] Step S2 includes steps S21-S23.

[0147] Step S21: Under the conditions of magnetron sputtering pressure of 4 mtorr, magnetron sputtering power of 4 kW, and magnetron sputtering time of 450 s, a nucleation layer with a thickness of 20 nm and made of AlN is grown by magnetron sputtering on a heterogeneous substrate.

[0148] Step S22: Under the conditions of growth temperature of 1000℃, growth pressure of 350 torr, and molar flow rate of growth source TMGa of 50 μmol / min, a buffer layer with a thickness of 1500 nm and made of GaN is epitaxially grown on the nucleation layer.

[0149] Step S23: Under the conditions of growth temperature of 1075℃, growth pressure of 200 torr, and molar flow rate of growth source TMGa of 130 μmol / min, a first N-type layer with a thickness of 1300 nm and material of GaN is epitaxially grown on the buffer layer to obtain the first epitaxial structure.

[0150] Step S3: Remove the first epitaxial structure from the reaction chamber. Under the conditions of corrosion voltage of 20V and corrosion time of 5min, perform electrochemical corrosion treatment on the first N-type layer of the first epitaxial structure to transform the first N-type layer into a second N-type layer with multiple pores inside, thereby obtaining the second epitaxial structure.

[0151] The porosity of the porous layer is 10%, and the diameter of each pore is 500 nm.

[0152] Step S4: A dislocation suppression layer and a template layer containing the target group III nitride are sequentially grown on the second epitaxial structure to obtain the third epitaxial structure.

[0153] Step S4 includes steps S41-S42.

[0154] Step S41: Place the second epitaxial structure into the reaction chamber, and grow a dislocation suppression layer with a thickness of 5 nm and made of SiN on the second N-type layer under the conditions of growth temperature of 950℃, growth pressure of 150 torr and molar flow rate of growth source SiH4 of 500 sccm.

[0155] Step S42: Under the conditions of growth temperature of 1000℃, growth pressure of 630 torr, and growth source GaCl molar flow rate of 50 μmol / min, a template layer with a thickness of 300 μm and material of GaN is grown on the dislocation suppression layer.

[0156] Step S5: The third epitaxial structure is peeled off along the pore layer to obtain the nitride template.

[0157] Example 4

[0158] This embodiment provides a method for preparing a nitride template, which differs from Embodiment 1 in that: the buffer layer includes an AlGaN layer and a target group III nitride layer grown sequentially. Step S22: The growth of the buffer layer includes:

[0159] (1) An AlGaN layer with a thickness of 10 nm was epitaxially grown on the nucleation layer under the conditions of a temperature of 950 °C, a pressure of 30 torr, and a molar flow ratio of TMAl / TMGa of the growth source of 25%.

[0160] (2) Under the conditions of growth temperature of 850℃, growth pressure of 40 torr and growth source TMGa molar flow rate of 5 μmol / min, a target group III nitride layer with a thickness of 400 nm and material of GaN was epitaxially grown on the AlGaN layer.

[0161] Example 5

[0162] This embodiment provides a method for preparing a nitride template, which differs from Embodiment 2 in that: the buffer layer includes an AlGaN layer and a target group III nitride layer grown sequentially. Step S22: The growth of the buffer layer includes:

[0163] (1) An AlGaN layer with a thickness of 50 nm was epitaxially grown on the nucleation layer under the conditions of a temperature of 1200℃, a pressure of 50 torr, and a molar flow ratio of TMAl / TMGa of the growth source of 75%.

[0164] (2) Under the conditions of growth temperature of 950℃, growth pressure of 60 torr and growth source TMGa molar flow rate of 200 μmol / min, a target group III nitride layer with a thickness of 600 nm and material of GaN was epitaxially grown on the AlGaN layer.

[0165] Example 6

[0166] This embodiment provides a method for preparing a nitride template, which differs from Embodiment 3 in that: the buffer layer includes an AlGaN layer and a target group III nitride layer grown sequentially. Step S22: The growth of the buffer layer includes:

[0167] (1) An AlGaN layer with a thickness of 30 nm was epitaxially grown on the nucleation layer under the conditions of a temperature of 1080℃, a pressure of 40 torr, and a molar flow ratio of TMAl / TMGa of the growth source of 50%.

[0168] (2) Under the conditions of growth temperature of 900℃, growth pressure of 50 torr and growth source TMGa molar flow rate of 100 μmol / min, a target group III nitride layer with a thickness of 500 nm and material of GaN was epitaxially grown on the AlGaN layer.

[0169] Example 7

[0170] This embodiment provides a method for preparing a nitride template, which differs from Embodiment 3 in that: the doping element in the first N-type layer includes Si, and the doping concentration of the doping element is 1E19cm⁻¹. -3 .

[0171] Example 8

[0172] This embodiment provides a method for preparing a nitride template, which differs from Embodiment 6 in that: the doping element in the first N-type layer includes Si, and the doping concentration of the doping element is 1E19cm⁻¹. -3 .

[0173] Example 9

[0174] This embodiment provides a method for preparing a nitride template, which differs from Example 3 in that the target group III nitride is AlN.

[0175] Example 10

[0176] This embodiment provides a method for preparing a nitride template, which differs from Embodiment 3 in that the heterogeneous substrate is a silicon carbide substrate.

[0177] Example 11

[0178] This embodiment provides a method for preparing a nitride template, which differs from Embodiment 3 in that the material of the nucleation layer is GaN.

[0179] Example 12

[0180] This embodiment provides a method for preparing a nitride template, which differs from Embodiment 3 in that the material of the buffer layer is AlN.

[0181] Example 13

[0182] This embodiment provides a method for preparing a nitride template, which differs from Embodiment 3 in that the material of the dislocation suppression layer is AlGaN.

[0183] Example 14

[0184] This embodiment provides a method for preparing a nitride template, which differs from Example 6 in that the target group III nitride is AlN.

[0185] Example 15

[0186] This embodiment provides a method for preparing a nitride template, which differs from Embodiment 6 in that the heterogeneous substrate is a silicon carbide substrate.

[0187] Example 16

[0188] This embodiment provides a method for preparing a nitride template, which differs from Embodiment 6 in that the material of the nucleation layer is GaN.

[0189] Example 17

[0190] This embodiment provides a method for preparing a nitride template, which differs from Embodiment 6 in that the material of the buffer layer is AlN.

[0191] Example 18

[0192] This embodiment provides a method for preparing a nitride template, which differs from Embodiment 6 in that the material of the dislocation suppression layer is AlGaN.

[0193] Example 19

[0194] This embodiment provides a method for preparing a nitride template, which differs from Example 6 in that the material of the target group III nitride layer is AlN.

[0195] Comparative Example 1

[0196] This embodiment provides a method for preparing a nitride template, which includes the following steps S1-S3.

[0197] Step S1: Provide a heterogeneous substrate required for growing a template layer containing the target group III nitride.

[0198] The target group III nitride is GaN, and the heterostructure is a sapphire substrate.

[0199] Step S2: A core layer, a buffer layer containing the target group III nitride, and a first N-type layer containing the target group III nitride are sequentially stacked and grown on a heterogeneous substrate to obtain a first epitaxial structure. Step S2 includes steps S21-S23.

[0200] Step S21: Under the conditions of magnetron sputtering pressure of 6 mtorr, magnetron sputtering power of 5 kW, and magnetron sputtering time of 600 s, a nucleation layer with a thickness of 30 nm and material of AlN is grown by magnetron sputtering on a heterogeneous substrate.

[0201] Step S22: Under the conditions of growth temperature of 1100℃, growth pressure of 500 torr, and molar flow rate of growth source TMGa of 100 μmol / min, a buffer layer with a thickness of 3000 nm and made of GaN is epitaxially grown on the nucleation layer.

[0202] Step S23: Under the conditions of growth temperature of 1100℃, growth pressure of 250 torr, and molar flow rate of growth source TMGa of 200 μmol / min, a first N-type layer with a thickness of 2000 nm and made of GaN is epitaxially grown on the buffer layer to obtain the first epitaxial structure.

[0203] Step S3: A dislocation suppression layer and a template layer containing the target group III nitride are sequentially grown on the first epitaxial structure to obtain the fourth epitaxial structure.

[0204] Step S3 includes steps S31-S32.

[0205] Step S31: Place the fourth epitaxial structure into the reaction chamber, and grow a dislocation suppression layer with a thickness of 10 nm and made of SiN on the first N-type layer under the conditions of growth temperature of 1000℃, growth pressure of 200 torr and molar flow rate of growth source SiH4 of 1000 sccm.

[0206] Step S32: Under the conditions of growth temperature of 1050℃, growth pressure of 760 torr, and molar flow rate of growth source GaCl of 100 μmol / min, a template layer with a thickness of 500 μm and material of GaN is grown on the dislocation suppression layer to obtain a nitride template.

[0207] Comparative Example 2

[0208] This embodiment provides a method for preparing a nitride template, which includes the following steps S1-S3.

[0209] Step S1: Provide a heterogeneous substrate required for growing a template layer containing the target group III nitride.

[0210] The target group III nitride is GaN, and the heterostructure is a sapphire substrate.

[0211] Step S2: A core layer and a buffer layer containing the target group III nitride are sequentially stacked and grown on a heterogeneous substrate to obtain the fifth epitaxial structure.

[0212] Step S2 includes steps S21-S22.

[0213] Step S21: Under the conditions of magnetron sputtering pressure of 2 torr, magnetron sputtering power of 3 kW, and magnetron sputtering time of 300 s, a nucleation layer with a thickness of 10 nm and made of AlN is grown by magnetron sputtering on a heterogeneous substrate.

[0214] Step S22: Under the conditions of growth temperature of 900℃, growth pressure of 200 torr, and molar flow rate of growth source TMGa of 10 μmol / min, a buffer layer with a thickness of 100 nm and made of GaN is epitaxially grown on the nucleation layer to obtain the fifth epitaxial structure.

[0215] Step S3: Under the conditions of growth temperature of 950℃, growth pressure of 500 torr, and growth source GaCl molar flow rate of 10 μmol / min, a template layer containing the target group III nitride, with a thickness of 500 μm and material of GaN, is grown on the fifth epitaxial structure (specifically the buffer layer) to obtain the nitride template.

[0216] The nitride templates obtained in Examples 1-19 and Comparative Examples 1-2 above can be tested using the cathodoluminescence (CL) method, and the test data shown in Table 1 can be obtained.

[0217] Table 1: Dislocation density of each nitride template in Examples 1-19 and Comparative Examples 1-2

[0218]

[0219]

[0220] It can be seen that, compared with Comparative Examples 1-2, the nitride templates of Examples 1-19 have a smaller dislocation density, and dislocation annihilation can be achieved without growing a very thick layer, thus ensuring the crystal quality of the nitride template (not greater than 500 μm).

[0221] In traditional methods, aluminum nitride is sputtered onto a substrate, and nitride material is grown on the aluminum nitride as a template layer. Although the crystal quality can be achieved with (002) < 100 arcsec and (102) < 200 arcsec, the epitaxial layer will inevitably crack due to stress when the thickness exceeds about 50 μm. The present invention can maintain the high crystal quality of the sputtered nucleation layer by growing a buffer layer on the nucleation layer. This buffer layer alleviates the stress caused by the difference in properties between the heterogeneous substrate and the nitride material, thereby reducing the defect density in the subsequent template layer and realizing the transition from the heterogeneous substrate to the growth of the nitride epitaxial material. By pre-treating the first N-type conductive layer grown on the buffer layer to be porous, a second N-type layer with a porous layer is formed. The porosity of the porous layer greatly reduces the internal stress of the subsequently grown nitride material.

[0222] Meanwhile, since pretreatment may cause dislocation growth in the material above the type II N layer, a dislocation suppression layer is used to cover the type II N layer to suppress secondary dislocation growth, further improving crystal quality. This allows the nitride material in the template layer to directly grow thick films with low stress and low defects, achieving a dislocation density of 10 at 500 μm. 6 cm -2 The effect is on a scale of [amount missing]. In summary, compared with traditional nitride template preparation methods, this invention has the advantage of lower dislocation density at the same material thickness.

[0223] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the invention without departing from the principles and spirit of the invention, and all such changes should fall within the protection scope of the claims of the present invention.

Claims

1. A method for preparing a nitride template, characterized in that, Includes the following steps: Provide a heterogeneous substrate required for growing a template layer containing the target group III nitride; A first epitaxial structure is obtained by sequentially stacking and growing a core layer, a buffer layer containing the target group III nitride, and a first N-type layer containing the target group III nitride on the heterostructure substrate. The first epitaxial structure is preprocessed to transform the first N-type layer into a second N-type layer with multiple pores inside, thereby obtaining a second epitaxial structure; wherein, the second N-type layer includes a porous layer, and the multiple pores are located within the porous layer; A misalignment suppression layer and a template layer containing the target group III nitride are sequentially grown on the second epitaxial structure to obtain a third epitaxial structure. The third epitaxial structure is peeled off along the porous layer to obtain a nitride template; wherein the nitride template includes at least a portion of a second N-type layer, the misalignment suppression layer, and the template layer stacked together.

2. The preparation method according to claim 1, characterized in that, A first epitaxial structure is obtained by sequentially stacking and growing a core layer, a buffer layer containing the target group III nitride, and a first N-type layer containing the target group III nitride on the heterostructure substrate, thereby obtaining the first epitaxial structure comprising: Under the conditions of magnetron sputtering pressure of 2-6 mtorr, magnetron sputtering power of 3-5 kW, and magnetron sputtering time of 300-600 s, the nucleation layer with a thickness of 10-30 nm is grown by magnetron sputtering on the heterogeneous substrate. The buffer layer is grown on the nucleation layer; Under the conditions of a growth temperature of 1050–1100℃, a growth pressure of 150–250 torr, and a molar flow rate of TMGa growth source of 50–200 μmol / min, a first N-type layer with a thickness of 500–2000 nm is epitaxially grown on the buffer layer to obtain the first epitaxial structure: And / or, the target group III nitride includes at least one of aluminum nitride or gallium nitride; and / or, the material of the nucleation layer is a group III nitride.

3. The preparation method according to claim 2, characterized in that, Growing the buffer layer includes: Under the conditions of growth temperature of 900-1100℃, growth pressure of 200-500 torr, and molar flow rate of TMGa growth source of 10-100 μmol / min, the buffer layer with a thickness of 100-3000 nm is epitaxially grown on the nucleation layer. Alternatively, the buffer layer comprises an AlGaN layer and a target group III nitride layer grown sequentially; growing the buffer layer includes: Under the conditions of growth temperature of 950-1200℃, growth pressure of 30-50 torr, and growth source TMAl / TMGa molar flow ratio of 25%-75%, an AlGaN layer with a thickness of 10-50 nm is epitaxially grown on the nucleation layer. Under the conditions of growth temperature of 850–950℃, growth pressure of 40–60 torr, and molar flow rate of growth source TMGa of 5–200 μmol / min, the target group III nitride layer with a thickness of 400–600 nm is epitaxially grown on the AlGaN layer.

4. The preparation method according to claim 1, characterized in that, Preprocessing of the first epitaxial structure includes: The first epitaxial structure is removed from the reaction chamber, and under the conditions of corrosion voltage of 10-30V and corrosion time of 1-10min, the first N-type layer of the first epitaxial structure is subjected to electrochemical corrosion treatment to transform the first N-type layer into a second N-type layer with multiple pores inside.

5. The preparation method according to claim 1, characterized in that, The second N-type layer further includes a first sub-N-type layer and a second sub-N-type layer. The first sub-N-type layer, the porous layer, and the second sub-N-type layer are stacked sequentially. The first sub-N-type layer is located between the porous layer and the buffer layer, and the second sub-N-type layer is located between the porous layer and the misalignment suppression layer.

6. The preparation method according to claim 1, characterized in that, The porosity of the pore layer is 1% to 20%; and / or, the diameter of each pore is 100 to 1000 nm.

7. The preparation method according to any one of claims 1-6, characterized in that, The doping elements in the first N-type layer include at least Si / Ge, and the doping concentration of the doping elements is 1E18 to 1E20 cm⁻¹. -3 .

8. The preparation method according to any one of claims 1-6, characterized in that, The material of the dislocation suppression layer comprises at least silicon nitride; and / or, growing the dislocation suppression layer in the second epitaxial structure includes: The second epitaxial structure is placed in the reaction chamber; under the conditions of growth temperature of 900-1000℃, growth pressure of 100-200 torr, and molar flow rate of growth source SiH4 of 100-1000 sccm, a dislocation suppression layer with a thickness of 1-10 nm is grown on the second N-type layer. And / or, growing a template layer containing the target group III nitride includes: Under the conditions of growth temperature of 950–1050℃, growth pressure of 500–760 torr, and molar flow rate of GaCl growth source of 10–100 μmol / min, a template layer with a thickness of 50–500 μm is grown on the dislocation suppression layer.

9. A nitride template, characterized in that, The nitride template is prepared using the method for preparing a low-defect-density nitride template as described in any one of claims 1-8.

10. A semiconductor device, characterized in that, The semiconductor device comprises a nitride template prepared by any one of the preparation methods described in claims 1-8.

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