Growth method of patterned aluminum nitride buffer layer and semiconductor device

Abstract

The present invention provides a method for growing a patterned aluminum nitride buffer layer and a semiconductor device. The method comprises: placing a substrate in a reaction chamber of an MOCVD device; adjusting the environmental conditions in the reaction chamber for a first time, introducing hydrogen, nitrogen, or a mixture of hydrogen and nitrogen into the reaction chamber as a carrier gas, and introducing an aluminum source, a gallium source, and ammonia into the reaction chamber to grow an AlGaN layer on the substrate; continuously introducing the carrier gas into the reaction chamber, stopping the introduction of the aluminum source and gallium source into the reaction chamber, and adjusting the environmental conditions in the reaction chamber for a second time, etching and recrystallizing the AlGaN layer to generate an island-shaped aluminum nitride buffer. The present invention destroys the Ga-N bonds in the AlGaN layer by etching, causing Ga atoms to desorb from the AlGaN layer and recrystallize into a patterned AlN buffer layer material, so that the subsequently grown nitride material becomes lateral epitaxial, which can reduce the dislocation and defect density of the epitaxial material.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and in particular to a method for growing a patterned aluminum nitride buffer layer and a semiconductor device. Background Art

[0002] Group III nitride materials have characteristics such as wide bandgap, high electron saturation velocity, good radiation resistance and high-temperature performance, making them particularly suitable for applications in optoelectronic devices, power electronic devices, microwave power devices, etc. Currently, commonly used devices based on Group III nitride materials include light-emitting diodes (LEDs), laser diodes (LDs), heterojunction field-effect transistors (HFETs), metal semiconductor field effect transistors (MESFETs), and metal-oxide-semiconductor field-effect transistors (MOSFETs), with a wide range of applications.

[0003] The large lattice mismatch and difference in thermal expansion coefficient between nitride and sapphire result in high dislocation and defect densities in nitride materials grown on substrates, severely impacting device performance. Patterned substrate technology can transform the longitudinal epitaxy of nitride materials into lateral epitaxy, effectively reducing dislocations and defects in epitaxial materials, and has been widely used in nitride device fabrication. However, due to the diverse substrates used for nitrides, including but not limited to silicon carbide, sapphire, silicon, diamond, and aluminum nitride, some substrates, such as silicon carbide, have stable chemical and physical properties and are difficult to etch and pattern. This limits the use of patterned substrate technology and makes it difficult to reduce the dislocation and defect density of epitaxial materials through patterned substrate technology. Summary of the Invention

[0004] The embodiments of the present invention provide a method for growing a patterned aluminum nitride buffer layer and a semiconductor device to solve the problem that the substrate has stable chemical and physical properties, which makes it difficult to etch and pattern it, and it is difficult to reduce the dislocation and defect density of the epitaxial material through patterned substrate technology.

[0005] In a first aspect, an embodiment of the present invention provides a method for growing a patterned aluminum nitride buffer layer, comprising:

[0006] Place the substrate into the reaction chamber of the MOCVD equipment;

[0007] Adjusting the environmental conditions in the reaction chamber for the first time, introducing hydrogen, nitrogen, or a mixture of hydrogen and nitrogen as a carrier gas, and introducing an aluminum source, a gallium source, and ammonia into the reaction chamber to grow an AlGaN layer on the substrate;

[0008] The carrier gas is continuously introduced into the reaction chamber, the aluminum source and gallium source are stopped, and the environmental conditions in the reaction chamber are adjusted for the second time. The AlGaN layer is etched and recrystallized to form an island-shaped aluminum nitride buffer layer.

[0009] In a possible implementation, before adjusting the environmental conditions in the reaction chamber for the first time, the method for growing the patterned aluminum nitride buffer layer further includes:

[0010] The ambient temperature in the reaction chamber is adjusted for the third time, and a carrier gas is introduced into the reaction chamber to pre-treat the surface of the substrate and remove impurities on the surface of the substrate;

[0011] The substrate includes sapphire, SiC, Si, diamond, GaN or AlN.

[0012] In a possible implementation, adjusting the ambient temperature in the reaction chamber for the third time includes:

[0013] The temperature in the reaction chamber is increased to within a first preset temperature range, and the pressure in the reaction chamber is adjusted to within a first preset pressure range.

[0014] In a possible implementation, the first preset temperature range is 900° C. to 1500° C., and the first preset pressure range is 50 mbar to 1000 mbar.

[0015] In one possible implementation, after adjusting the ambient temperature in the reaction chamber for a third time and introducing a carrier gas into the reaction chamber to pre-treat the surface of the substrate and remove impurities on the substrate surface, the method for growing the patterned aluminum nitride buffer layer further includes:

[0016] The ambient temperature in the reaction chamber is adjusted for the fourth time, and the carrier gas is continuously introduced into the reaction chamber, as well as ammonia gas or aluminum source is introduced into the reaction chamber to improve the surface of the substrate.

[0017] In a possible implementation, adjusting the ambient temperature in the reaction chamber for the fourth time includes:

[0018] The temperature in the reaction chamber is adjusted to within a second preset temperature range, and the pressure in the reaction chamber is adjusted to within a second preset pressure range.

[0019] In a possible implementation, the second preset temperature range is 900° C. to 1500° C., and the second preset pressure range is 50 mbar to 1000 mbar.

[0020] In a possible implementation, adjusting the environmental conditions in the reaction chamber for the first time includes:

[0021] Adjusting the temperature in the reaction chamber to within a third preset temperature range, and adjusting the pressure in the reaction chamber to within a third preset pressure range;

[0022] The second adjustment of the environmental conditions in the reaction chamber includes:

[0023] The temperature in the reaction chamber is adjusted to within a fourth preset temperature range, and the pressure in the reaction chamber is adjusted to within a fourth preset pressure range.

[0024] In a possible implementation, the third preset temperature range is 400° C. to 1500° C., and the third preset pressure range is 50 mbar to 1000 mbar;

[0025] The fourth preset temperature range is 400° C. to 1500° C., and the fourth preset pressure range is 50 mbar to 1000 mbar.

[0026] In a second aspect, an embodiment of the present invention provides a semiconductor device, including a product prepared by the method for growing a patterned aluminum nitride buffer layer as described in the first aspect or any possible implementation of the first aspect.

[0027] An embodiment of the present invention provides a method for growing a patterned aluminum nitride buffer layer and a semiconductor device. The method comprises the following steps: first, an AlGaN layer is grown on a substrate; then, a carrier gas and ammonia are continuously introduced into a reaction chamber; the introduction of an aluminum source and a gallium source into the reaction chamber is stopped; and the environmental conditions in the reaction chamber are adjusted a second time. The AlGaN layer is etched and recrystallized to generate an island-shaped aluminum nitride buffer layer. The Ga-N bonds in the AlGaN layer are destroyed by etching, so that Ga atoms are desorbed from the AlGaN layer and recrystallized into a patterned AlN buffer layer material. This allows the subsequently grown nitride material to be lateral epitaxial, thereby reducing the dislocation and defect density of the epitaxial material. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0029] Figure 1 This is a flow chart of a method for growing a patterned aluminum nitride buffer layer provided by an embodiment of the present invention;

[0030] Figure 2 Schematic diagram of temperature changes during the execution of the method for growing a patterned aluminum nitride buffer layer provided by an embodiment of the present invention;

[0031] Figure 3 It is a structural schematic diagram of a product prepared by the growth method of a patterned aluminum nitride buffer layer provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0032] In the following description, specific details such as particular system structures and techniques are provided for purposes of illustration, not limitation, to facilitate a thorough understanding of the embodiments of the present invention. However, it will be apparent to those skilled in the art that the present invention may be practiced in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted so as not to obscure the description of the present invention with unnecessary detail.

[0033] In order to make the purpose, technical solutions and advantages of the present invention more clear, specific embodiments will be described below with reference to the accompanying drawings.

[0034] See also Figure 1 , which shows a flow chart of the implementation of the method for growing a patterned aluminum nitride buffer layer provided by an embodiment of the present invention. The method is described in detail as follows:

[0035] In S101 , a substrate is placed in a reaction chamber of a MOCVD (Metal-organic Chemical Vapor Deposition) device.

[0036] In S102, the environmental conditions in the reaction chamber are adjusted for the first time, and hydrogen, nitrogen, or a mixture of hydrogen and nitrogen is introduced into the reaction chamber as a carrier gas, and an aluminum source, a gallium source, and ammonia are introduced into the reaction chamber to grow an AlGaN layer on the substrate.

[0037] Growing an AlGaN layer on a substrate requires certain environmental conditions, such as temperature, pressure, etc. Therefore, before growing the AlGaN layer on the substrate, the environmental conditions in the reaction chamber of the MOCVD equipment are first adjusted to ensure that the reaction chamber meets the environmental conditions required for growing the AlGaN layer on the substrate.

[0038] The adjustment may be made according to the environmental conditions required for subsequent growth of the AlGaN layer.

[0039] The carrier gas can be hydrogen, nitrogen, or a mixture of hydrogen and nitrogen. The carrier gas can transport the aluminum source, gallium source, and ammonia, and can also regulate the pressure in the reaction chamber.

[0040] The aluminum source may be trimethylaluminum or other aluminum sources that can grow an AlGaN layer, and is not specifically limited here.

[0041] The gallium source may be trimethylgallium or other gallium sources capable of growing an AlGaN layer, and is not specifically limited here.

[0042] By introducing aluminum source, gallium source and ammonia into the reaction chamber, an AlGaN layer can be grown on the substrate.

[0043] In the above S102, the flow rate of the carrier gas can be greater than 0 sccm, the flow rate of the ammonia gas can be greater than 0 sccm, the flow rate of the aluminum source can be greater than 0 sccm, the flow rate of the gallium source can be greater than 0 sccm, and the time for introducing the aluminum source, gallium source and ammonia gas can be greater than 0s. The specific size can be set according to actual needs and is not specifically limited here.

[0044] In S103 , the carrier gas is continuously introduced into the reaction chamber, the aluminum source and the gallium source are stopped, and the environmental conditions in the reaction chamber are adjusted for the second time. The AlGaN layer is etched and recrystallized to form an island-shaped aluminum nitride buffer layer.

[0045] Etching and recrystallizing the AlGaN layer requires certain environmental conditions, such as temperature, pressure, etc. Therefore, before etching and recrystallizing the AlGaN layer, the environmental conditions in the MOCVD equipment's reaction chamber are first adjusted a second time to ensure that the reaction chamber meets the environmental conditions required for etching and recrystallizing the AlGaN layer.

[0046] The introduction of hydrogen at high temperature can etch and destroy the Ga-N bond, causing Ga atoms to desorb from the AlGaN buffer layer and recrystallize to form a patterned AlN buffer layer. Of course, if nitrogen is introduced as a carrier gas, at high temperatures (greater than 900°C), GaN will decompose, causing Ga atoms to desorb from the AlGaN buffer layer and recrystallize to form a patterned AlN buffer layer. In a hydrogen environment, the etching rate of the AlGaN layer is greater than that in a nitrogen environment.

[0047] In the above S103, the flow rate of the introduced ammonia gas can be ≥0 sccm, the flow rate of the introduced carrier gas can be >0 sccm, and the etching and recrystallization time can be >0 s. The specific sizes can be set according to actual needs and are not specifically limited here.

[0048] This embodiment first grows an AlGaN layer on a substrate, then continuously introduces a carrier gas and ammonia into the reaction chamber, stops introducing an aluminum source and a gallium source, and adjusts the environmental conditions in the reaction chamber a second time. The AlGaN layer is then etched and recrystallized to form an island-shaped aluminum nitride buffer layer. The etching destroys the Ga-N bonds in the AlGaN layer, causing Ga atoms to desorb from the AlGaN layer and recrystallize into a patterned AlN buffer layer material. This allows the subsequent growth of the nitride material to be lateral epitaxial, thereby reducing the dislocation and defect density of the epitaxial material. The method used in this embodiment is not affected by the substrate material and can achieve an island-shaped aluminum nitride buffer layer on different substrates, resolving the problem that some substrates cannot be patterned and the nitride material grown thereon has a high defect density.

[0049] In some possible implementations, after S103, the method for growing the patterned aluminum nitride buffer layer may further include:

[0050] Continue to grow nitride materials, such as gallium nitride, etc., on the substrate and the aluminum nitride buffer layer.

[0051] In some embodiments, after S101 and before S102, the method for growing the patterned aluminum nitride buffer layer may further include:

[0052] The ambient temperature in the reaction chamber is adjusted for the third time, and a carrier gas is introduced into the reaction chamber to pre-treat the surface of the substrate and remove impurities on the surface of the substrate;

[0053] The substrate includes sapphire, SiC, Si, diamond, GaN or AlN.

[0054] Since there may be some impurities on the substrate surface, the substrate surface is usually pre-treated before etching to remove impurities on the substrate surface. The substrate surface may have organic impurities, such as oil stains, and other particles.

[0055] Because substrate surface pretreatment requires certain environmental conditions, the reaction chamber's environmental conditions are first adjusted a third time. For example, the temperature and pressure can be adjusted to ensure the reaction chamber meets the required environmental conditions for substrate surface pretreatment. A carrier gas is then introduced into the reaction chamber to pretreat the substrate surface and remove impurities. The carrier gas reacts with certain impurities on the substrate surface, removing them. Some impurities on the substrate surface may volatilize at a certain temperature, thereby achieving the purpose of removing these impurities.

[0056] In the above-mentioned step of introducing carrier gas into the reaction chamber to pre-treat the surface of the substrate and remove impurities on the surface of the substrate, the flow rate of the carrier gas introduced into the reaction chamber can be greater than 0 sccm. Its specific size can be set according to actual needs and is not specifically limited here.

[0057] In some embodiments, the third adjustment of the ambient temperature in the reaction chamber includes:

[0058] The temperature in the reaction chamber is increased to within a first preset temperature range, and the pressure in the reaction chamber is adjusted to within a first preset pressure range.

[0059] In the process of heating the temperature in the reaction chamber to the first preset temperature range, the heating rate can be greater than 0°C / second. The specific value can be set according to equipment conditions or other requirements and is not specifically limited here.

[0060] In some embodiments, the first preset temperature range is 900° C. to 1500° C., and the first preset pressure range is 50 mbar to 1000 mbar.

[0061] The above third adjustment of the environmental conditions in the reaction chamber, finally, the temperature in the reaction chamber is adjusted to a temperature within the first preset temperature range, and the pressure is adjusted to a pressure within the first preset pressure range, which can be set according to actual needs and are not specifically limited here.

[0062] In some embodiments, after adjusting the ambient temperature in the reaction chamber for the third time and introducing a carrier gas into the reaction chamber to pre-treat the surface of the substrate and remove impurities on the substrate surface, and before S102, the method for growing the patterned aluminum nitride buffer layer may further include:

[0063] The ambient temperature in the reaction chamber is adjusted for the fourth time, and the carrier gas is continuously introduced into the reaction chamber, as well as ammonia gas or aluminum source is introduced into the reaction chamber to improve the surface of the substrate.

[0064] The aluminum source may be trimethylaluminum or other aluminum sources that can improve the surface of the substrate, and is not specifically limited here.

[0065] Improving the substrate surface requires certain environmental conditions, such as temperature, pressure, etc. Therefore, before improving the substrate surface, the environmental conditions in the reaction chamber of the MOCVD equipment are first adjusted for the fourth time to ensure that the reaction chamber meets the environmental conditions required for improving the substrate surface.

[0066] The substrate may have some suspended components. When ammonia is introduced, its decomposition generates H bonds, which can then form bonds with the suspended components on the substrate surface, making the substrate surface more active. When an aluminum source is introduced, the substrate surface is quickly covered with a layer. Due to the high ductility of aluminum, the substrate covered with aluminum source is more suitable for subsequent growth than the original substrate.

[0067] This embodiment improves the substrate surface and can provide better growth conditions for the subsequent growth of the buffer layer.

[0068] In the above-mentioned process of continuously introducing carrier gas into the reaction chamber, and introducing ammonia or aluminum source into the reaction chamber to improve the surface of the substrate, the flow rate of the carrier gas can be >0 sccm, the flow rate of the ammonia or aluminum source can be >0 sccm, and the time of introducing the ammonia or aluminum source can be >0s. The specific sizes can be set according to actual needs and are not specifically limited here.

[0069] In some embodiments, the fourth adjustment of the ambient temperature in the reaction chamber includes:

[0070] The temperature in the reaction chamber is adjusted to within a second preset temperature range, and the pressure in the reaction chamber is adjusted to within a second preset pressure range.

[0071] In the process of adjusting the temperature in the reaction chamber to the second preset temperature range, the adjustment rate can be greater than or equal to 0°C / second. The specific size can be set according to equipment conditions or other requirements, and is not specifically limited here.

[0072] In some embodiments, the second preset temperature range is 900° C. to 1500° C., and the second preset pressure range is 50 mbar to 1000 mbar.

[0073] The above fourth adjustment of the environmental conditions in the reaction chamber, finally, the temperature in the reaction chamber is adjusted to a temperature within the second preset temperature range, and the pressure is adjusted to a pressure within the second preset pressure range, which can be set according to actual needs and are not specifically limited here.

[0074] In some embodiments, the first adjustment of the environmental conditions in the reaction chamber includes:

[0075] Adjusting the temperature in the reaction chamber to within a third preset temperature range, and adjusting the pressure in the reaction chamber to within a third preset pressure range;

[0076] The second adjustment of the environmental conditions in the reaction chamber includes:

[0077] The temperature in the reaction chamber is adjusted to within a fourth preset temperature range, and the pressure in the reaction chamber is adjusted to within a fourth preset pressure range.

[0078] In the process of adjusting the temperature in the reaction chamber to the third preset temperature range, the adjustment rate can be greater than or equal to 0°C / second. The specific size can be set according to equipment conditions or other requirements, and is not specifically limited here.

[0079] In the process of adjusting the temperature in the reaction chamber to the fourth preset temperature range, the adjustment rate can be greater than or equal to 0°C / second. The specific size can be set according to equipment conditions or other requirements, and is not specifically limited here.

[0080] In some embodiments, the third preset temperature range is 400° C. to 1500° C., and the third preset pressure range is 50 mbar to 1000 mbar;

[0081] The fourth preset temperature range is 400° C. to 1500° C., and the fourth preset pressure range is 50 mbar to 1000 mbar.

[0082] The above-mentioned first adjustment of the environmental conditions in the reaction chamber, and finally, the temperature in the reaction chamber is adjusted to a temperature within the third preset temperature range, and the pressure is adjusted to a pressure within the third preset pressure range, which can be set according to actual needs and are not specifically limited here.

[0083] The above-mentioned second adjustment of the environmental conditions in the reaction chamber, ultimately, the temperature in the reaction chamber is adjusted to a temperature within the fourth preset temperature range, and the pressure is adjusted to a pressure within the fourth preset pressure range. These can be set according to actual needs and are not specifically limited here.

[0084] It should be noted that the first adjustment, second adjustment, third adjustment and fourth adjustment mentioned in this application do not indicate the order of adjustment, but are only used to distinguish each adjustment to the environmental conditions in the reaction chamber.

[0085] In the present application, after the substrate is placed in the reaction chamber of the MOCVD equipment, a carrier gas can be continuously introduced into the reaction chamber. In different steps, the carrier gas introduced can be the same or different, and can be adjusted according to actual needs and actual application conditions.

[0086] In some embodiments, the method for growing a patterned aluminum nitride buffer layer may include the following steps:

[0087] Step 1: Place the substrate into the reaction chamber of the MOCVD equipment, and adjust the environmental conditions in the reaction chamber for the third time so that the reaction chamber meets the environmental conditions required for substrate pretreatment.

[0088] Step 2: Introduce carrier gas into the reaction chamber to pre-treat the surface of the substrate and remove impurities on the surface of the substrate.

[0089] Step 3: Adjust the ambient temperature in the reaction chamber for the fourth time, and continue to introduce carrier gas into the reaction chamber, as well as ammonia or aluminum source into the reaction chamber to improve the surface of the substrate.

[0090] Step 4: Adjust the environmental conditions in the reaction chamber for the first time, and introduce hydrogen, nitrogen or a mixture of hydrogen and nitrogen as a carrier gas into the reaction chamber, as well as aluminum source, gallium source and ammonia into the reaction chamber to grow an AlGaN layer on the substrate.

[0091] Step 5: Continue to introduce carrier gas into the reaction chamber, stop introducing aluminum source and gallium source into the reaction chamber, and adjust the environmental conditions in the reaction chamber for the second time, etch and recrystallize the AlGaN layer to form an island-shaped aluminum nitride buffer layer.

[0092] The temperature changes during the execution of each step can be referred to Figure 2 . Figure 2 In the figure, the horizontal axis represents time, and the vertical axis represents temperature. 1 represents the temperature change in step 1, 2 represents the temperature change in step 2, 3 represents the temperature change in step 3, 4 represents the temperature change in step 4, and 5 represents the temperature change in step 5.

[0093] It should be noted that Figure 2 This is just a schematic diagram of a possible temperature change during the execution of the growth method of the patterned aluminum nitride buffer layer. In actual applications, the temperature change during the execution of the growth method of the patterned aluminum nitride buffer layer may also take other forms of changes, which are not specifically limited here.

[0094] In a specific application scenario, the substrate can be a sapphire substrate. In step one, when the environmental conditions in the reaction chamber are adjusted for the third time, the temperature rise rate in the reaction chamber can be 1.5°C / s; in step two, the temperature of the reaction chamber can be 1150°C, the pressure can be 200mbar, the carrier gas can be hydrogen, and the flow rate of the hydrogen can be 20slm; in step three, after the environmental conditions in the reaction chamber are adjusted for the fourth time, the temperature in the reaction chamber can be 1100°C, the flow rate of the carrier gas can be 20slm, an aluminum source is introduced to improve the surface of the substrate, the aluminum source introduced can be trimethylaluminum, the flow rate of the aluminum source can be 20sccm, and the time for introducing the aluminum source can be 30s; in step four, the environmental conditions in the reaction chamber are adjusted. After the first adjustment of the parts, the temperature of the reaction chamber can be 600°C, the pressure can be 650mbar, the flow rate of the carrier gas can be 35slm, the flow rate of the ammonia can be 50slm, the aluminum source can be trimethylaluminum, the flow rate of the aluminum source can be 50sccm, the time of the aluminum source can be 3 minutes, the gallium source can be trimethylgallium, the flow rate of the gallium source can be 20sccm, and the time of the gallium source can be 3 minutes; in step 5, after the second adjustment of the environmental conditions in the reaction chamber, the temperature of the reaction chamber can be 1250°C, the pressure can be 650mbar, the carrier gas flow rate can be 100slm, the flow rate of the ammonia can be 5slm, and the time of the ammonia can be 30 minutes. In step 5, under high temperature, high pressure and hydrogen environment, the Ga-N bond in AlGaN is destroyed, the Ga atoms are desorbed and separated from the epitaxial layer on the surface, the Al-N bond will not be destroyed due to its high bond energy, and recrystallizes at high temperature to form an aluminum nitride buffer layer with an island-like pattern structure.

[0095] This embodiment provides a method for growing an aluminum nitride buffer layer with an island-shaped pattern structure on different substrates. This growth technology can be used to achieve an aluminum nitride buffer layer with an island-shaped pattern structure, so that the subsequent growth mode of the nitride becomes lateral epitaxy, thereby achieving the purpose of reducing the defect density.

[0096] It should be understood that the size of the serial numbers of the steps in the above embodiments does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0097] The products prepared by the above-mentioned growth method of the patterned aluminum nitride buffer layer are as follows Figure 3 As shown, it includes a substrate 31 and an aluminum nitride buffer layer 32 with an island-shaped pattern structure located on the substrate.

[0098] Corresponding to the above-mentioned method for growing a patterned aluminum nitride buffer layer, an embodiment of the present invention also provides a semiconductor device, including a product prepared using any of the above methods for growing a patterned aluminum nitride buffer layer, and having the beneficial effects of any of the above methods for growing a patterned aluminum nitride buffer layer.

[0099] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant description of other embodiments.

[0100] The embodiments described above are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention, and should all be included in the scope of protection of the present invention.

Claims

1. A method for growing a patterned aluminum nitride buffer layer, characterized in that: include: Place the substrate into the reaction chamber of the MOCVD equipment; Adjusting the environmental conditions in the reaction chamber for the first time, introducing hydrogen, nitrogen, or a mixture of hydrogen and nitrogen as a carrier gas into the reaction chamber, and introducing an aluminum source, a gallium source, and ammonia into the reaction chamber to grow an AlGaN layer on the substrate; Continue to introduce the carrier gas into the reaction chamber, stop introducing the aluminum source and the gallium source into the reaction chamber, adjust the environmental conditions in the reaction chamber for a second time, and etch and recrystallize the AlGaN layer to form an island-shaped aluminum nitride buffer layer; The second adjustment of the environmental conditions in the reaction chamber includes: The temperature in the reaction chamber is adjusted to 400° C. to 1500° C., and the pressure in the reaction chamber is adjusted to 50 mbar to 1000 mbar.

2. The method for growing a patterned aluminum nitride buffer layer according to claim 1, wherein: Before adjusting the environmental conditions in the reaction chamber for the first time, the method for growing the patterned aluminum nitride buffer layer further includes: Adjusting the ambient temperature in the reaction chamber for a third time and introducing the carrier gas into the reaction chamber to pre-treat the surface of the substrate and remove impurities on the surface of the substrate; The substrate includes sapphire, SiC, Si, diamond, GaN or AlN.

3. The method for growing a patterned aluminum nitride buffer layer according to claim 2, wherein: The third adjustment of the ambient temperature in the reaction chamber comprises: The temperature in the reaction chamber is increased to within a first preset temperature range, and the pressure in the reaction chamber is adjusted to within a first preset pressure range.

4. The method for growing a patterned aluminum nitride buffer layer according to claim 3, wherein: The first preset temperature range is 900° C. to 1500° C., and the first preset pressure range is 50 mbar to 1000 mbar.

5. The method for growing a patterned aluminum nitride buffer layer according to claim 2, wherein: After adjusting the ambient temperature in the reaction chamber for the third time and introducing the carrier gas into the reaction chamber to pre-treat the surface of the substrate and remove impurities on the surface of the substrate, the method for growing the patterned aluminum nitride buffer layer further includes: The ambient temperature in the reaction chamber is adjusted for the fourth time, and the carrier gas is continuously introduced into the reaction chamber, and ammonia or aluminum source is introduced into the reaction chamber to improve the surface of the substrate.

6. The method for growing a patterned aluminum nitride buffer layer according to claim 5, wherein: The fourth adjustment of the ambient temperature in the reaction chamber includes: The temperature in the reaction chamber is adjusted to within a second preset temperature range, and the pressure in the reaction chamber is adjusted to within a second preset pressure range.

7. The method for growing a patterned aluminum nitride buffer layer according to claim 6, wherein: The second preset temperature range is 900° C. to 1500° C., and the second preset pressure range is 50 mbar to 1000 mbar.

8. The method for growing a patterned aluminum nitride buffer layer according to any one of claims 1 to 7, wherein: The first adjustment of the environmental conditions in the reaction chamber includes: Adjusting the temperature within the reaction chamber to within a third preset temperature range, and adjusting the pressure within the reaction chamber to within a third preset pressure range; The second adjustment of the environmental conditions in the reaction chamber includes: The temperature in the reaction chamber is adjusted to within a fourth preset temperature range, and the pressure in the reaction chamber is adjusted to within a fourth preset pressure range.

9. The method for growing a patterned aluminum nitride buffer layer according to claim 8, wherein: The third preset temperature range is 400° C. to 1500° C., and the third preset pressure range is 50 mbar to 1000 mbar; The fourth preset temperature range is 400° C. to 1500° C., and the fourth preset pressure range is 50 mbar to 1000 mbar.

10. A semiconductor device, characterized in that: The invention comprises a product prepared by the method for growing a patterned aluminum nitride buffer layer according to any one of claims 1 to 9.

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