Preparation Method of Silicon-Based Substrate High Electron Mobility Transistor Epitaxial Wafer

Abstract

The present disclosure provides a method for preparing a silicon-based substrate high electron mobility transistor epitaxial wafer, belonging to the technical field of semiconductor devices. The surface on the silicon-based substrate is treated with hydrogen to remove oxides, avoiding oxygen entering the AlN nucleation layer as an impurity and affecting the quality of the AlN nucleation layer, thereby improving the quality. A silicon source is introduced into the reaction chamber to treat the surface of the silicon-based substrate. The smaller-diameter Si atoms can fill the pits, improving the flatness. Ammonia is introduced into the reaction chamber to treat the surface of the silicon-based substrate and form a SiN film. While ensuring the flatness of the thin layer grown on the silicon-based substrate, the SiN film provides a good growth basis for the AlN nucleation layer, which can effectively improve the flatness of the thin layer grown on the silicon-based substrate and reduce the impurities in the subsequently grown epitaxial structure, improving the flatness, uniformity and crystal quality of the finally obtained HEMT epitaxial wafer.

Description

Technical Field

[0001] The present disclosure relates to the technical field of semiconductor devices, and particularly to a method for preparing a silicon-based substrate high electron mobility transistor epitaxial wafer. Background Art

[0002] HEMT (High Electron Mobility Transistor) is a heterojunction field effect transistor, which is widely used in various electrical appliances. The HEMT epitaxial wafer is the basis for fabricating HEMT devices. The HEMT epitaxial wafer includes a substrate and an AlN nucleation layer, a GaN channel layer, an AlGaN barrier layer, and a GaN cap layer that are sequentially stacked on the substrate.

[0003] Since the silicon-based substrate has relatively good thermal conductivity, the silicon-based substrate is often used for the growth of HEMT epitaxial wafers. However, the natural oxide on the surface of the silicon-based substrate, such as silicon oxide, is prone to decompose into oxygen atoms during high-temperature growth. The oxygen atoms diffuse into the interior of the AlN nucleation layer to become impurities and affect the flatness of the AlN nucleation layer, thereby affecting the uniformity of the subsequent epitaxial layer. Summary of the Invention

[0004] Embodiments of the present disclosure provide a method for preparing a silicon-based substrate high electron mobility transistor epitaxial wafer, which can improve the surface uniformity and quality of the silicon-based substrate high electron mobility transistor. The technical solution is as follows:

[0005] Embodiments of the present disclosure provide a high electron mobility transistor epitaxial wafer. The preparation method of the high electron mobility transistor epitaxial wafer includes:

[0006] Providing a silicon-based substrate;

[0007] Using hydrogen to perform a deoxidation treatment on the surface of the silicon-based substrate;

[0008] Introducing a silicon source into the reaction chamber to treat the surface of the silicon-based substrate;

[0009] Introducing ammonia gas into the reaction chamber to treat the surface of the silicon-based substrate and generate a SiN thin film;

[0010] Growing an AlN nucleation layer, a GaN channel layer, an AlGaN barrier layer, and a GaN cap layer on the SiN thin film in sequence.

[0011] Optionally, the introducing a silicon source into the reaction chamber to treat the surface of the silicon-based substrate includes:

[0012] Introducing the silicon source into the reaction chamber for 5 - 10 minutes to treat the surface of the silicon-based substrate.

[0013] Optionally, introducing a silicon source into the reaction chamber to treat the surface of the silicon-based substrate includes:

[0014] Introducing a silicon source with a flow rate of 50 - 200 sccm into the reaction chamber to treat the surface of the silicon-based substrate.

[0015] Optionally, introducing a silicon source into the reaction chamber to treat the surface of the silicon-based substrate under the condition of a temperature of 900 - 1100 °C.

[0016] Optionally, introducing ammonia gas into the reaction chamber to treat the surface of the silicon-based substrate and form a SiN film includes:

[0017] Introducing ammonia gas into the reaction chamber for 1 - 2 min to treat the surface of the silicon-based substrate and form a SiN film.

[0018] Optionally, introducing ammonia gas into the reaction chamber to treat the surface of the silicon-based substrate and form a SiN film includes:

[0019] Introducing ammonia gas with a flow rate of 100 - 500 sccm into the reaction chamber to treat the surface of the silicon-based substrate and form a SiN film.

[0020] Optionally, introducing ammonia gas into the reaction chamber to treat the surface of the silicon-based substrate and form a SiN film includes:

[0021] Introducing ammonia gas into the reaction chamber under the condition of a temperature of 900 - 1000 °C to treat the surface of the silicon-based substrate and form a SiN film.

[0022] Optionally, after introducing ammonia gas into the reaction chamber to treat the surface of the silicon-based substrate and form a SiN film, and before sequentially growing an AlN nucleation layer on the SiN film, the preparation method further includes:

[0023] Pre-introducing an Al source into the reaction chamber to deposit an Al atomic layer on the SiN film.

[0024] Optionally, pre-introducing an Al source with a flow rate of 50 - 200 sccm into the reaction chamber for 10 s - 100 s under the condition of a temperature of 1000 - 1100 °C to deposit an Al atomic layer on the SiN film.

[0025] Optionally, the thickness of the Al atomic layer is 1 - 5 nm.

[0026] The beneficial effects brought by the technical solutions provided in the embodiments of the present disclosure include:

[0027] First, use hydrogen to perform deoxidation treatment on the surface of the silicon-based substrate, which can remove the oxide on the surface of the silicon-based substrate, avoid oxygen entering the AlN nucleation layer as an impurity and affecting the quality of the AlN nucleation layer, and can improve the quality of the subsequent grown HEMT epitaxial wafer. Since after the surface of the silicon-based substrate is treated with hydrogen for deoxidation, tiny pits will form on the surface of the silicon-based substrate. Therefore, introduce a silicon source into the reaction chamber to treat the surface of the silicon-based substrate. The silicon source homologous to the silicon-based substrate can provide Si atoms, and the Si atoms with a smaller diameter can fill the pits, further improving the surface flatness of the silicon-based substrate. Then introduce ammonia into the reaction chamber to treat the surface of the silicon-based substrate and generate a SiN film, which can make the surface where the AlN nucleation layer needs to be grown in a film state rather than a state of scattered independent atomic islands, ensure the flatness of the thin layer grown on the silicon-based substrate, and the SiN film also provides a good growth foundation for the AlN nucleation layer, effectively improving the flatness of the thin layer grown on the silicon-based substrate, reducing impurities in the subsequent grown epitaxial structure, and improving the flatness, uniformity and crystal quality of the finally obtained HEMT epitaxial wafer. Description of the Drawings

[0028] To more clearly illustrate the technical solutions in the embodiments of the present disclosure, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following described drawings are only some embodiments of the present disclosure. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0029] Figure 1 It is a flowchart of a method for preparing a silicon-based substrate high electron mobility transistor epitaxial wafer provided by an embodiment of the present disclosure;

[0030] Figure 2 It is a schematic structural diagram of a high electron mobility transistor epitaxial wafer provided by an embodiment of the present disclosure;

[0031] Figure 3 It is a flowchart of another method for preparing a silicon-based substrate high electron mobility transistor epitaxial wafer provided by an embodiment of the present disclosure;

[0032] Figure 4 It is a schematic structural diagram of another high electron mobility transistor epitaxial wafer provided by an embodiment of the present disclosure. Detailed Embodiments

[0033] To make the purpose, technical solutions and advantages of the present disclosure clearer, the following will further describe the embodiments of the present disclosure in detail with reference to the drawings.

[0034] Unless otherwise defined, technical or scientific terms used herein shall have the ordinary meaning as understood by those of ordinary skill in the art to which this disclosure pertains. The terms "first", "second", "third" and similar terms used in the specification and claims of this patent application of the disclosure do not denote any order, quantity or importance, but are only used to distinguish different components. Similarly, terms such as "a" or "an" do not denote a quantity limitation, but rather denote the presence of at least one. Terms such as "comprising" or "including" mean that the elements or items appearing before "comprising" or "including" cover the elements or items listed after "comprising" or "including" and their equivalents, and do not exclude other elements or items. Terms such as "connected" or "coupled" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. Terms such as "upper", "lower", "left", "right", "top", "bottom" are only used to indicate relative positional relationships, and when the absolute position of the object being described changes, the relative positional relationships may also change accordingly.

[0035] Figure 1 is a flowchart of a method for preparing a silicon-based substrate high electron mobility transistor epitaxial wafer provided by an embodiment of the disclosure. As Figure 1 shown, an embodiment of the disclosure provides a high electron mobility transistor epitaxial wafer. The method for preparing the high electron mobility transistor epitaxial wafer includes:

[0036] S101: Provide a silicon-based substrate.

[0037] S102: Use hydrogen to perform a deoxidation treatment on the surface of the silicon-based substrate.

[0038] S103: Introduce a silicon source into the reaction chamber to treat the surface of the silicon-based substrate.

[0039] S104: Introduce ammonia into the reaction chamber to treat the surface of the silicon-based substrate and form a SiN film.

[0040] S105: Sequentially grow an AlN nucleation layer, a GaN channel layer, an AlGaN barrier layer, and a GaN cap layer on the SiN film.

[0041] First, the surface on the silicon-based substrate is treated with hydrogen to remove the oxide on the surface of the silicon-based substrate, avoiding oxygen entering the AlN nucleation layer as an impurity and affecting the quality of the AlN nucleation layer, and improving the quality of the subsequent grown HEMT epitaxial wafer. After the surface on the silicon-based substrate is treated with hydrogen, tiny pits will form on the surface of the silicon-based substrate. Therefore, a silicon source is introduced into the reaction chamber to treat the surface of the silicon-based substrate. The silicon source homologous to the silicon-based substrate can provide Si atoms, and the Si atoms with smaller diameters can fill the pits, further improving the surface flatness of the silicon-based substrate. Then, ammonia is introduced into the reaction chamber to treat the surface of the silicon-based substrate and generate a SiN film, which can make the surface where the AlN nucleation layer needs to grow in a film state rather than a state of scattered independent atomic islands, ensuring the flatness of the thin layer grown on the silicon-based substrate. The SiN film also provides a good growth basis for the AlN nucleation layer, effectively improving the flatness of the thin layer grown on the silicon-based substrate and reducing the impurities in the subsequent grown epitaxial structure, and improving the flatness, uniformity and crystal quality of the finally obtained HEMT epitaxial wafer.

[0042] It should be noted that when a silicon source is introduced into the reaction chamber, the silicon source decomposes in the high-temperature environment of the reaction chamber, and some Si atoms will separate and fill into the pits existing on the surface of the silicon-based substrate.

[0043] In step S102, the surface of the silicon-based substrate is treated with hydrogen, including:

[0044] Hydrogen is introduced into the reaction chamber, and the surface of the silicon-based substrate is treated at a temperature of 100 - 1200 °C.

[0045] Treating the surface of the silicon-based substrate with hydrogen under the above temperature conditions can effectively remove the oxide on the surface of the silicon-based substrate, remove the oxygen atoms contained in the oxide, and improve the quality of the epitaxial structure grown on the surface of the silicon-based substrate.

[0046] Optionally, the surface of the silicon-based substrate is treated with hydrogen for 5 - 10 min at a temperature of 100 - 1200 °C.

[0047] Treating the surface of the silicon-based substrate with hydrogen for 5 - 10 min at a temperature of 100 - 1200 °C can ensure that the oxide on the surface of the silicon-based substrate is fully removed, effectively improving the flatness and quality of the epitaxial structure grown on the finally obtained silicon-based substrate.

[0048] Exemplarily, the surface of the silicon-based substrate is treated with hydrogen under the condition that the pressure in the reaction chamber is 50 - 150 mbar, which can promote the removal of the oxide.

[0049] Optionally, in step S103, introducing a silicon source into the reaction chamber to treat the surface of the silicon-based substrate includes:

[0050] Introducing the silicon source into the reaction chamber for 5 - 10 minutes to treat the surface of the silicon-based substrate.

[0051] Introducing the silicon source into the reaction chamber for 5 - 10 minutes to treat the surface of the silicon-based substrate can ensure that Si atoms in the silicon source have sufficient time to layer on the surface of the silicon-based substrate and effectively fill all pits, improving the flatness and quality of the finally obtained HEMT epitaxial wafer.

[0052] Optionally, introducing a silicon source into the reaction chamber to treat the surface of the silicon-based substrate includes:

[0053] Introducing the silicon source with a flow rate of 50 - 200 sccm into the reaction chamber to treat the surface of the silicon-based substrate.

[0054] When the flow rate of the silicon source is within the above range, it can ensure that Si atoms fill the pits in a relatively stable and steady state, effectively ensuring the flatness of the surface of the silicon-based substrate and not excessively increasing the manufacturing cost of the HEMT.

[0055] Exemplarily, introducing a silicon source into the reaction chamber to treat the surface of the silicon-based substrate under the condition that the temperature is 900 - 1100 °C.

[0056] Introducing the silicon source to treat the silicon-based substrate on the premise that the temperature is within the above range can promote the stable and effective filling of pits by Si atoms, ensuring the flatness of the surface of the finally obtained silicon-based substrate.

[0057] Exemplarily, introducing a silicon source into the reaction chamber to treat the surface of the silicon-based substrate under the condition that the pressure in the reaction chamber is 50 - 100 mbar. It can ensure the stable filling of Si atoms.

[0058] Optionally, step S104, introducing ammonia into the reaction chamber to treat the surface of the silicon-based substrate and generate a SiN film includes:

[0059] Introducing ammonia into the reaction chamber for 1 - 2 minutes to treat the surface of the silicon-based substrate and generate a SiN film.

[0060] Since there are not too many Si atoms remaining on the surface of the silicon-based substrate, introducing ammonia into the reaction chamber briefly to treat the surface of the silicon-based substrate can generate a relatively flat SiN film without excessively increasing the manufacturing cost. And the ammonia in the reaction chamber will not be too much to affect the growth of the subsequent epitaxial structure.

[0061] Optionally, introducing ammonia into the reaction chamber to treat the surface of the silicon-based substrate and generate a SiN film includes:

[0062] Ammonia gas with a flow rate of 100 - 500 sccm is introduced into the reaction chamber to treat the surface of the silicon-based substrate and form a SiN film.

[0063] When the flow rate of ammonia gas introduced into the reaction chamber is within the above range, the remaining Si atoms and ammonia gas can react stably to grow the SiN film, and the preparation cost will not be increased excessively.

[0064] Optionally, introducing ammonia gas into the reaction chamber to treat the surface of the silicon-based substrate and form a SiN film includes:

[0065] Introducing ammonia gas into the reaction chamber to treat the surface of the silicon-based substrate and form a SiN film under the condition that the temperature is 900 - 1000 °C.

[0066] When introducing a silicon source to treat the silicon-based substrate on the premise that the temperature is within the above range, the reaction between Si atoms and ammonia gas can be promoted, ensuring the surface flatness of the finally obtained silicon-based substrate.

[0067] Exemplarily, the growth thickness of the SiN film is 1 - 10 nm.

[0068] For ease of understanding, here Figure 2 , Figure 2 is a schematic structural diagram of a high electron mobility transistor epitaxial wafer provided by an embodiment of the present disclosure. Referring to Figure 2 , it can be seen that the high electron mobility transistor epitaxial wafer includes a silicon-based substrate 1 and a SiN film 2, an AlN nucleation layer 3, a GaN channel layer 4, an AlGaN barrier layer 5, and a GaN cap layer 6 stacked in sequence on the silicon-based substrate 1.

[0069] Figure 3 is a flowchart of another method for preparing a silicon-based substrate high electron mobility transistor epitaxial wafer provided by an embodiment of the present disclosure. Referring to Figure 3 , it can be seen that the method for preparing a silicon-based substrate high electron mobility transistor epitaxial wafer may include:

[0070] S201: Provide a silicon-based substrate.

[0071] S202: Use hydrogen gas to perform a deoxidation treatment on the surface of the silicon-based substrate.

[0072] S203: Introduce a silicon source into the reaction chamber to treat the surface of the silicon-based substrate.

[0073] S204: Introduce ammonia gas into the reaction chamber to treat the surface of the silicon-based substrate and form a SiN film.

[0074] Steps S201 - S204 can refer to Figure 1 Steps S101 - S104 therein, so they will not be elaborated here.

[0075] S205: Pre-introduce an Al source into the reaction chamber to deposit Al atomic layers on the SiN thin film.

[0076] Due to the relatively low lateral mobility of Al atoms, pre-depositing Al atomic layers is beneficial to improving the flatness of the subsequent AlN nucleation layer, thereby enhancing the uniformity of the entire epitaxial layer. It is conducive to improving the overall quality of HEMT epitaxial wafers.

[0077] Optionally, under the condition of a temperature of 1000 - 1100 °C, pre-introduce the Al source into the reaction chamber for 10 s - 100 s with a flow rate of 50 - 200 sccm to deposit Al atomic layers on the SiN thin film.

[0078] Under the above temperature conditions, introducing the Al source with a flow rate of 50 - 200 sccm into the reaction chamber for a certain duration can stack a relatively stable and moderately thick Al atomic layer on the SiN thin film, ensuring the stable and uniform growth of the subsequent AlN nucleation layer.

[0079] Optionally, when introducing the Al source into the reaction chamber, the pressure of the reaction chamber is 40 - 70 mbar. The low pressure can promote the lateral extension of Al atoms to deposit on the SiN thin film.

[0080] Exemplarily, the thickness of the Al atomic layer is 1 - 5 nm.

[0081] When the thickness of the Al atomic layer is within the above range, it can provide a good growth foundation for the AlN nucleation layer.

[0082] It should be noted that in step S205, when introducing the Al source into the reaction chamber, there are no other gases except the carrier gas or other types of organometallic sources other than the Al source introduced.

[0083] S206: Grow an AlN nucleation layer on the SiN thin film.

[0084] Optionally, adjust the temperature to 1100 °C - 1200 °C, grow an AlN nucleation layer with a thickness of 150 - 300 nm, and the growth pressure is between 40 - 70 mbar. A better-quality AlN nucleation layer can be obtained.

[0085] S207: Grow an AlGaN buffer layer on the AlN nucleation layer.

[0086] Optionally, the growth conditions of the AlGaN buffer layer include: the growth temperature is 1000 °C - 1200 °C, and the pressure is between 40 - 70 mbar. A better-quality AlGaN buffer layer can be obtained.

[0087] Exemplarily, the thickness of the AlGaN buffer layer is between 2.0 and 3.0 micrometers, the Al composition in the AlGaN buffer layer gradually changes from high to low, and the Al composition range in the AlGaN buffer layer is 0.2 to 0.8. It can release stress to a certain extent and improve the quality of the finally obtained HEMT epitaxial wafer.

[0088] S208: Grow a GaN high-resistance layer on the AlGaN buffer layer.

[0089] Optionally, the growth conditions of the GaN high-resistance layer include: the growth temperature is between 950 °C and 1050 °C, and the pressure is between 40 and 70 mbar. A GaN high-resistance layer with better quality can be obtained.

[0090] Exemplarily, the thickness of the GaN high-resistance layer is between 1.0 and 1.5 micrometers, and the GaN high-resistance layer is doped with carbon elements in the range of 1019 cm -3 ~1020 cm -3 between. Improve the quality of the finally obtained HEMT epitaxial wafer.

[0091] S209: Grow a GaN channel layer on the GaN high-resistance layer.

[0092] Optionally, the growth conditions of the GaN channel layer include: the growth temperature is between 1050 °C and 1150 °C, and the pressure is between 150 and 250 mbar. A GaN channel layer with better quality can be obtained.

[0093] Exemplarily, the thickness of the GaN channel layer is between 1.0 and 1.5 micrometers. Improve the quality of the finally obtained HEMT epitaxial wafer. The obtained GaN channel layer has better quality.

[0094] S210: Grow an AlN insertion layer on the GaN channel layer.

[0095] Optionally, the growth temperature of the AlN insertion layer is 1050 °C to 1150 °C, and the growth pressure of the AlN insertion layer is 40 to 70 mbar. An AlN insertion layer with better quality can be obtained.

[0096] S211: Grow an AlGaN barrier layer on the AlN insertion layer.

[0097] Optionally, the growth temperature of the AlGaN barrier layer is 1050 °C to 1150 °C, and the growth pressure of the AlGaN barrier layer is 40 to 70 mbar. The obtained AlGaN barrier layer has better quality.

[0098] In an implementation provided by the present disclosure, the growth temperature of the AlGaN barrier layer can be 1020 °C. The present disclosure does not limit this.

[0099] S212: Grow a GaN cap layer on the AlGaN barrier layer.

[0100] Optionally, the growth temperature of the GaN cap layer is 1050°C to 1150°C, and the growth pressure of the AlGaN barrier layer is 40 to 70 mbar. The obtained GaN cap layer has good quality.

[0101] S213: Lower the temperature of the reaction chamber and cool it to room temperature in a nitrogen atmosphere to end the epitaxial growth.

[0102] Step S213 can release the thermal stress inside the HEMT epitaxial wafer to a certain extent and improve the quality of the finally obtained HEMT epitaxial wafer.

[0103] It should be noted that in the embodiments of the present disclosure, a Veeco K465i or C4 or RB MOCVD (Metal Organic Chemical Vapor Deposition) device is used to implement the growth method of the LED. High-purity H2 (hydrogen) or high-purity N2 (nitrogen) or a mixed gas of high-purity H2 and high-purity N2 is used as the carrier gas, high-purity NH3 is used as the N source, trimethylgallium (TMGa) and triethylgallium (TEGa) are used as the gallium sources, trimethylindium (TMIn) is used as the indium source, silane (SiH4) is used as the N-type dopant, trimethylaluminum (TMAl) is used as the aluminum source, and bis(cyclopentadienyl)magnesium (CP2Mg) is used as the P-type dopant.

[0104] Figure 4 is a schematic structural diagram of another high electron mobility transistor epitaxial wafer provided by the embodiments of the present disclosure. Refer to Figure 4 It can be seen that the high electron mobility transistor epitaxial wafer may include a silicon-based substrate 1 and an SiN thin film 2, an AlN nucleation layer 3, an AlGaN buffer layer 7, a GaN high-resistance layer 8, a GaN channel layer 4, an AlN insertion layer 9, an AlGaN barrier layer 5, and a GaN cap layer 6 that are sequentially stacked on the silicon-based substrate 1.

[0105] Optionally, the thickness of the AlN nucleation layer 3 is 150 to 300 nm. It can ensure that the AlN nucleation layer 3 has good quality and provide a good growth foundation for the HEMT epitaxial wafer.

[0106] Exemplarily, the thickness of the AlGaN buffer layer 7 is 1 to 1.5 microns. The obtained AlGaN buffer layer 7 has good quality.

[0107] Exemplarily, the thickness of the GaN high-resistance layer 8 is 300 to 600 nm. It can play a good buffering effect.

[0108] Optionally, the thickness of the GaN channel layer 4 can be 100 to 400 nm.

[0109] The thickness of the GaN channel layer 4 is appropriate, and while the cost is reasonable, it can effectively improve the quality of the high electron mobility transistor epitaxial wafer.

[0110] In one implementation provided by the present disclosure, the thickness of the GaN channel layer 4 can be 400 nm. The present disclosure does not limit this.

[0111] Figure 4 relatively Figure 1 Regarding the structure of the HEMT epitaxial wafer, an AlGaN buffer layer 7, a GaN high-resistance layer 8, and an AlN insertion layer 9 are added. On the one hand, the negative impact brought by the lattice mismatch of the bottom layer is relatively small. On the other hand, two-dimensional electron gases are formed at the interfaces where the AlN insertion layer 9 contacts the GaN channel layer 4 and between the AlN insertion layer 9 and the AlGaN barrier layer 5. By increasing the accumulation of carriers at the interfaces through the two-dimensional electron gases, the usage effect of the high electron mobility transistor epitaxial wafer can be ensured.

[0112] Optionally, the thickness of the AlN insertion layer 9 is 0.5 - 2 nm.

[0113] When the thickness of the AlN insertion layer 9 is within the above range, two-dimensional electron gases can be effectively formed, and the cost will not be increased too much.

[0114] In one implementation provided by the present disclosure, the thickness of the AlN insertion layer 9 can be 2 nm. The present disclosure does not limit this.

[0115] Optionally, the thickness of the AlGaN barrier layer 5 can be in the range of 15 - 40 nm. The quality of the high electron mobility transistor epitaxial wafer can be ensured.

[0116] In one implementation provided by the present disclosure, the thickness of the AlGaN barrier layer 5 can be 100 nm. The present disclosure does not limit this.

[0117] Exemplarily, the GaN cap layer 6 can be a P-type GaN layer. It is convenient for preparation and acquisition.

[0118] Optionally, the thickness of the GaN cap layer 6 is 3 - 10 nm. The overall quality of the obtained GaN cap layer 6 is good.

[0119] Exemplarily, the impurity in the GaN cap layer 6 is Mg. It is convenient for preparation and acquisition.

[0120] It should be noted that Figure 4 This is only one implementation of the high electron mobility transistor epitaxial wafer provided by the embodiments of the present disclosure. In other implementations provided by the present disclosure, the high electron mobility transistor epitaxial wafer can also be other forms of high electron mobility transistor epitaxial wafers including a reflective layer. The present disclosure does not limit this.

[0121] The above does not impose any formal restrictions on the present disclosure. Although the present disclosure has been disclosed above through embodiments, it is not intended to limit the present disclosure. Any person skilled in the relevant art can, without departing from the scope of the technical solution of the present disclosure, make some changes or modifications to the above-disclosed technical content to form equivalent embodiments with equivalent changes. However, as long as the content does not depart from the technical solution of the present disclosure, any simple modification, equivalent change, and modification made to the above embodiments based on the technical essence of the present disclosure still fall within the scope of the technical solution of the present disclosure.

Claims

1. A method for preparing an epitaxial wafer of a silicon-based substrate high electron mobility transistor, characterized in that The preparation method of the high electron mobility transistor epitaxial wafer includes: Providing a silicon-based substrate; Using hydrogen to perform a deoxidation treatment on the surface of the silicon-based substrate; Introducing a silicon source into the reaction chamber to process the surface of the silicon-based substrate so as to improve the surface flatness of the silicon-based substrate; Introducing ammonia gas into the reaction chamber to process the surface of the silicon-based substrate and generate a SiN film; Successively growing an AlN nucleation layer, a GaN channel layer, an AlGaN barrier layer, and a GaN cap layer on the SiN film.

2. The preparation method of the high electron mobility transistor epitaxial wafer according to claim 1, wherein The introducing a silicon source into the reaction chamber to process the surface of the silicon-based substrate includes: Introducing the silicon source into the reaction chamber for 5 - 10 minutes to process the surface of the silicon-based substrate.

3. The method for preparing a high electron mobility transistor epitaxial wafer according to claim 2, wherein The introducing a silicon source into the reaction chamber to process the surface of the silicon-based substrate includes: Introducing the silicon source with a flow rate of 50 - 200 sccm into the reaction chamber to process the surface of the silicon-based substrate.

4. The preparation method of the high electron mobility transistor epitaxial wafer according to any one of claims 1 - 3, characterized in that Introducing the silicon source into the reaction chamber to process the surface of the silicon-based substrate under the condition that the temperature is 900 - 1100 °C.

5. The preparation method of the high electron mobility transistor epitaxial wafer according to any one of claims 1 to 3, characterized in that, The introducing ammonia gas into the reaction chamber to process the surface of the silicon-based substrate and generate a SiN film includes: Introducing ammonia gas into the reaction chamber for 1 - 2 minutes to process the surface of the silicon-based substrate and generate a SiN film.

6. The method for preparing a high electron mobility transistor epitaxial wafer according to claim 5, characterized in that, The introducing ammonia gas into the reaction chamber to process the surface of the silicon-based substrate and generate a SiN film includes: Introducing ammonia gas with a flow rate of 100 - 500 sccm into the reaction chamber to process the surface of the silicon-based substrate and generate a SiN film.

7. The method for preparing a high electron mobility transistor epitaxial wafer according to any one of claims 1 to 3, characterized in that The introducing ammonia gas into the reaction chamber to process the surface of the silicon-based substrate and generate a SiN film includes: Introducing ammonia gas into the reaction chamber to process the surface of the silicon-based substrate and generate a SiN film under the condition that the temperature is 900 - 1000 °C.

8. The method for preparing a high electron mobility transistor epitaxial wafer according to any one of claims 1 to 3, characterized in that, After introducing ammonia gas into the reaction chamber to process the surface of the silicon-based substrate and generating a SiN film, and before successively growing an AlN nucleation layer on the SiN film, the preparation method further includes: Pre-introducing an Al source into the reaction chamber to lay an Al atomic layer on the SiN film.

9. The preparation method of the high electron mobility transistor epitaxial wafer according to claim 8, characterized in that Pre-introducing the Al source with a flow rate of 50 - 200 sccm into the reaction chamber for 10 s - 100 s under the condition that the temperature is 1000 - 1100 °C to lay an Al atomic layer on the SiN film.

10. The method for preparing a high electron mobility transistor epitaxial wafer according to claim 8, wherein The thickness of the Al atomic layer is 1 - 5 nm.

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