GaN-based HEMT epitaxial wafer

Abstract

The utility model relates to a GaN-based HEMT (High Electron Mobility Transistor) epitaxial wafer, in particular to the field of semiconductor materials, and the GaN-based HEMT epitaxial wafer comprises a substrate, and a nucleating layer, a high-resistance layer, a channel layer, an insertion layer, a barrier layer and a cap layer which are sequentially arranged on the substrate from bottom to top, the high-resistance layer comprises a P-type AlGaN layer and an N-type GaN layer which are arranged in an alternate and matched mode in the direction perpendicular to the arrangement direction of the high-resistance layer. According to the GaN-based HEMT epitaxial wafer provided by the utility model, the high-resistance layer with high crystal growth quality is obtained by designing the specific high-resistance layer and utilizing the high-resistance layer with a specific structure, so that electric leakage can be avoided, and the voltage withstanding performance of a device can be improved.

Description

Technical Field

[0001] This utility model relates to the field of semiconductor materials, specifically to a GaN-based HEMT epitaxial wafer. Background Technology

[0002] Currently, gallium nitride (GaN), as a representative of third-generation wide-bandgap semiconductor materials, has attracted increasing attention due to its wider bandgap, larger critical breakdown electric field, high saturation electron velocity, high temperature resistance, radiation resistance, good thermal conductivity, and low dielectric constant. The two-dimensional electron gas with high electron concentration and high electron mobility that can be formed at the AlGaN / GaN heterojunction interface makes it a promising candidate for high-power, high-voltage HEMT devices.

[0003] The existing epitaxial growth method for GaN-based high electron mobility transistors (HEMTs) involves directly growing an AlN buffer layer, an AlxGa1-xN buffer layer, a GaN high-resistivity layer, a GaN channel layer, an AlN insertion layer, and an AlGaN barrier layer sequentially on a substrate (silicon or sapphire). Among these, the high-resistivity layer, due to its high resistance characteristics, can serve as an effective electron blocking layer, which helps to form a two-dimensional electron gas with high electron mobility in the AlGaN / GaN heterostructure. The current method for obtaining the GaN high-resistivity layer is to introduce high concentrations of impurities such as Fe and C during the epitaxial growth process.

[0004] For example, CN115360236A discloses a GaN HEMT device with a high-resistivity buffer layer and its fabrication method. The device includes, from bottom to top, a substrate, an AlN nucleation layer, a stress modulation layer, a high-resistivity buffer layer, a GaN channel layer, an AlN insertion layer, an AlGaN barrier layer, and a GaN capping layer. The high-resistivity buffer layer includes, from bottom to top, an Fe-doped GaN buffer layer, a hexagonal BN buffer layer, and a C-doped GaN buffer layer. The upper surface of the GaN capping layer is provided with a source electrode, a drain electrode, and a gate electrode spaced apart from each other. The source electrode and the drain electrode form ohmic contacts with the AlGaN barrier layer. The gate electrode forms a Schottky contact with the AlGaN barrier layer.

[0005] However, when high concentrations of impurities such as Fe and C are introduced during epitaxial growth to obtain a high-resistivity layer, the concentration of iron impurities is difficult to control due to the memory effect of iron doping, resulting in poor crystal quality. At the same time, carbon doping is easy to carry out at low temperature and low pressure, but the crystal quality of the epitaxial layer obtained at low temperature and low pressure will deteriorate. Therefore, there is an urgent need for a preparation process that can effectively improve the crystal growth quality of high-resistivity layers. Utility Model Content

[0006] In view of the problems existing in the prior art, the purpose of this utility model is to provide a GaN-based HEMT epitaxial wafer to solve the defects of poor crystal growth quality and leakage in the high resistivity layer.

[0007] To achieve this objective, the present invention adopts the following technical solution:

[0008] In a first aspect, this utility model provides a GaN-based HEMT epitaxial wafer, the GaN-based HEMT epitaxial wafer comprising:

[0009] The substrate, from bottom to top, consists of a nucleation layer, a high-resistivity layer, a channel layer, an insertion layer, a barrier layer, and a capping layer.

[0010] The high-resistivity layer includes P-type AlGaN layers and N-type GaN layers that are alternately arranged perpendicular to the direction in which the high-resistivity layer is set.

[0011] The GaN-based HEMT epitaxial wafer provided by this invention, by designing a specific high-resistivity layer and utilizing a high-resistivity layer with a specific structure, obtains a high-resistivity layer with high crystal growth quality, which helps to avoid leakage current and thus improves the withstand voltage performance of the device.

[0012] As a preferred technical solution of this utility model, the nucleation layer is an AlN nucleation layer with a thickness of 15-20nm.

[0013] As a preferred technical solution of this utility model, the high-resistivity layer is an N-type GaN layer with a first groove and a P-type AlGaN layer disposed in the first groove.

[0014] As a preferred technical solution of this utility model, the thickness of the N-type GaN layer with the first groove is 5-20 μm;

[0015] The depth of the first groove is 5-20 μm;

[0016] The width of the first groove is 2-2.5 μm;

[0017] The thickness of the P-type AlGaN layer disposed in the first groove is equal to the depth of the first groove.

[0018] As a preferred technical solution of this utility model, the high-resistivity layer is a P-type AlGaN layer with a second groove and an N-type GaN layer disposed in the second groove.

[0019] As a preferred technical solution of this utility model, the thickness of the P-type AlGaN layer with the second groove is 5-20μm;

[0020] The depth of the second groove is 5-20 μm;

[0021] The width of the second groove is 2-2.5 μm;

[0022] The thickness of the N-type GaN layer disposed in the second groove is equal to the depth of the second groove.

[0023] As a preferred technical solution of this utility model, the channel layer is a GaN channel layer with a thickness of 50-200nm.

[0024] As a preferred technical solution of this utility model, the insertion layer is an AlN insertion layer with a thickness of 1-1.5 nm.

[0025] As a preferred technical solution of this utility model, the barrier layer is an AlGaN barrier layer with a thickness of 20-30nm.

[0026] As a preferred technical solution of this utility model, the capping layer is a GaN capping layer with a thickness of 10-20nm.

[0027] Compared with existing technical solutions, this utility model has the following beneficial effects:

[0028] The GaN-based HEMT epitaxial wafer provided by this invention, by utilizing a specially designed high-resistivity layer and the synergistic relationship between the P-type AlGaN layer and the N-type GaN layer, improves the crystal growth quality of the resulting high-resistivity layer, thereby enhancing the breakdown voltage performance of the power device and helping to improve leakage current. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of a GaN-based HEMT epitaxial wafer provided in an embodiment of the present invention;

[0030] Figure 2 This is a schematic diagram of a GaN-based HEMT epitaxial wafer provided in Embodiment 1 of this utility model;

[0031] Figure 3 This is a schematic diagram of a GaN-based HEMT epitaxial wafer provided in Embodiment 2 of this utility model;

[0032] Figure 4 This is a schematic diagram of a GaN-based HEMT epitaxial wafer provided in Embodiment 3 of this utility model;

[0033] Figure 5 This is a schematic diagram of a GaN-based HEMT epitaxial wafer provided in Embodiment 4 of this utility model.

[0034] In the figure: 1-substrate, 2-nucleation layer, 3-high resistivity layer, 3.1-N-type GaN layer, 3.2-P-type AlGaN layer, 4-channel layer, 5-insertion layer, 6-barrier layer, 7-capping layer.

[0035] The present invention will now be described in further detail. However, the examples described below are merely simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention shall be determined by the claims. Detailed Implementation

[0036] To better illustrate this utility model and facilitate understanding of its technical solution, typical but non-limiting embodiments of this utility model are as follows:

[0037] This embodiment provides a GaN-based HEMT epitaxial wafer, such as Figure 1 As shown, the GaN-based HEMT epitaxial wafer comprises:

[0038] The substrate, from bottom to top, consists of a nucleation layer, a high-resistivity layer, a channel layer, an insertion layer, a barrier layer, and a capping layer.

[0039] The high-resistivity layer includes P-type AlGaN layers and N-type GaN layers that are alternately arranged perpendicular to the direction in which the high-resistivity layer is set.

[0040] In this invention, the high-resistivity layer is set in a direction perpendicular to the substrate surface. This direction is perpendicular to the high-resistivity layer setting direction, which is along the substrate surface. P-type AlGaN layers and N-type GaN layers are alternately set. For example, if the substrate is used as a reference and a three-axis coordinate system of xyz is adopted, the z-axis is the direction perpendicular to the substrate surface, which is the high-resistivity layer setting direction of this invention. At this time, the y-axis or x-axis is perpendicular to the high-resistivity layer setting direction.

[0041] The nucleation layer is an AlN nucleation layer with a thickness of 15-20 nm, such as 15 nm, 16 nm, 17 nm, 18 nm, 19 nm or 20 nm, but not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0042] The high-resistivity layer is an N-type GaN layer with a first groove and a P-type AlGaN layer disposed in the first groove.

[0043] Alternatively, the high-resistivity layer may be a P-type AlGaN layer with a second groove and an N-type GaN layer disposed within the second groove.

[0044] The thickness of the N-type GaN layer with the first groove is 5-20 μm, for example, it can be 5 μm, 6 μm, 8 μm, 10 μm, 12 μm, 14 μm, 16 μm, 18 μm or 20 μm, but is not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0045] The depth of the first groove is 5-20μm, for example, it can be 5μm, 6μm, 8μm, 10μm, 12μm, 14μm, 16μm, 18μm or 20μm, but is not limited to the listed values. Other unlisted values ​​within this range also meet the requirements.

[0046] The width of the first groove is 2-2.5 μm, for example, it can be 2 μm, 2.1 μm, 2.2 μm, 2.3 μm, 2.4 μm or 2.5 μm, but is not limited to the listed values. Other unlisted values ​​within this range also meet the requirements.

[0047] The thickness of the P-type AlGaN layer disposed in the first groove is equal to the depth of the first groove.

[0048] The thickness of the P-type AlGaN layer with the second groove is 5-20 μm, for example, it can be 5 μm, 6 μm, 8 μm, 10 μm, 12 μm, 14 μm, 16 μm, 18 μm or 20 μm, but is not limited to the listed values. Other unlisted values ​​within this range also meet the requirements.

[0049] The depth of the second groove is 5-20μm, for example, it can be 5μm, 6μm, 8μm, 10μm, 12μm, 14μm, 16μm, 18μm or 20μm, but is not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0050] The width of the second groove is 2-2.5 μm, for example, it can be 2 μm, 2.1 μm, 2.2 μm, 2.3 μm, 2.4 μm or 2.5 μm, but is not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0051] The thickness of the N-type GaN layer disposed in the second groove is equal to the depth of the second groove.

[0052] The channel layer is a GaN channel layer with a thickness of 50-200nm, such as 50nm, 60nm, 80nm, 100nm, 120nm, 140nm, 160nm, 180nm or 200nm, but is not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0053] The insertion layer is an AlN insertion layer with a thickness of 1-1.5 nm, such as 1 nm, 1.1 nm, 1.2 nm, 1.3 nm, 1.4 nm or 1.5 nm, but is not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0054] The barrier layer is an AlGaN barrier layer with a thickness of 20-30nm, such as 20nm, 22nm, 24nm, 26nm, 28nm or 30nm, but not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0055] The capping layer is a GaN capping layer with a thickness of 10-20nm, such as 10nm, 12nm, 14nm, 16nm, 18nm or 20nm, but not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0056] Furthermore, this utility model provides a method for preparing the aforementioned GaN-based HEMT epitaxial wafer, the method comprising:

[0057] AlN nucleation layer growth, P-type AlGaN-N-type GaN high-resistivity layer growth, GaN channel layer growth, AlN insertion layer growth, AlGaN barrier layer growth, and GaN capping layer growth are performed sequentially on the substrate to obtain a GaN-based HEMT epitaxial wafer.

[0058] The growth temperature of the AlN nucleation layer is 600-1200℃, for example, it can be 600℃, 700℃, 800℃, 900℃, 1000℃, 1100℃ or 1200℃, but is not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0059] The growth pressure for the AlN nucleation layer is 50-200 mbar, for example, it can be 50 mbar, 60 mbar, 80 mbar, 100 mbar, 120 mbar, 140 mbar, 160 mbar, 180 mbar or 200 mbar, but is not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0060] The thickness of the AlN nucleation layer obtained by growing the AlN nucleation layer is 15-20nm, for example, it can be 15nm, 16nm, 17nm, 18nm, 19nm or 20nm, but is not limited to the listed values. Other unlisted values ​​within this range also meet the requirements.

[0061] The growth of the P-type AlGaN-N-type GaN high-resistivity layer includes sequential substrate growth, substrate trench etching, and trench filling growth.

[0062] The substrate growth includes N-type GaN layer growth or P-type AlGaN layer growth.

[0063] Wherein, when the base layer growth is N-type GaN layer growth, the trench filling growth is P-type AlGaN trench filling growth.

[0064] The carrier gas used in the growth of the N-type GaN layer includes nitrogen.

[0065] The flow rate of the carrier gas used in the growth of the N-type GaN layer is 50-100 slm, for example, it can be 50 slm, 60 slm, 70 slm, 80 slm, 90 slm or 100 slm, etc., but is not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0066] The Ga source used in the growth of the N-type GaN layer includes TMGa.

[0067] The flow rate of the Ga source used in the growth of the N-type GaN layer is 100-500 sccm, for example, it can be 100 sccm, 200 sccm, 300 sccm, 400 sccm or 500 sccm, but is not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0068] The nitrogen source used in the growth of the N-type GaN layer includes ammonia.

[0069] The nitrogen source flow rate used in the growth of the N-type GaN layer is 10-50 slm, for example, it can be 10 slm, 20 slm, 30 slm, 40 slm or 50 slm, but is not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0070] The silicon source used in the growth of the N-type GaN layer includes silane.

[0071] The flow rate of the silicon source used in the growth of the N-type GaN layer is 50-100 sccm, for example, it can be 50 sccm, 60 sccm, 70 sccm, 80 sccm, 90 sccm or 100 sccm, but is not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0072] The growth temperature in the N-type GaN layer growth is 1000-1100℃, for example, it can be 1000℃, 1020℃, 1040℃, 1060℃, 1080℃ or 1100℃, etc., but is not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0073] The growth pressure during the growth of the N-type GaN layer is 50-600 mbar, for example, it can be 50 mbar, 60 mbar, 80 mbar, 100 mbar, 200 mbar, 300 mbar, 400 mbar, 500 mbar or 600 mbar, but is not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0074] The doping concentration of the N-type GaN layer obtained by growing the N-type GaN layer is 1×10⁻⁶.17 -1×10 18 atom / cm 3 For example, it could be 1×10 17 atom / cm 3 2×10 17 atom / cm 3 4×10 17 atom / cm 3 6×10 17 atom / cm 3 8×10 17 atom / cm 3 Or 1×10 18 atom / cm 3 The values ​​may include, but are not limited to, the listed values; other unlisted values ​​within this range also meet the requirements.

[0075] In this utility model, atom / cm 3 This refers to the number of atoms contained in a unit volume.

[0076] The carrier gas used in the P-type AlGaN trench filling growth includes nitrogen.

[0077] The flow rate of the carrier gas used in the P-type AlGaN trench filling growth is 50-100 slm, for example, it can be 50 slm, 60 slm, 70 slm, 80 slm, 90 slm or 100 slm, etc., but is not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0078] The Ga source used in the P-type AlGaN trench filling growth includes TMGa.

[0079] The flow rate of the Ga source used in the P-type AlGaN trench filling growth is 100-500 sccm, for example, it can be 100 sccm, 200 sccm, 300 sccm, 400 sccm or 500 sccm, but is not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0080] The nitrogen source used in the P-type AlGaN trench filling growth includes ammonia.

[0081] The flow rate of the nitrogen source used in the P-type AlGaN trench filling growth is 10-50 slm, for example, it can be 10 slm, 20 slm, 30 slm, 40 slm or 50 slm, but is not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0082] The aluminum source used in the P-type AlGaN trench filling growth includes TMAl.

[0083] The flow rate of the aluminum source used in the P-type AlGaN trench filling growth is 50-200 sccm, for example, it can be 50 sccm, 60 sccm, 80 sccm, 100 sccm, 120 sccm, 140 sccm, 160 sccm, 180 sccm or 200 sccm, but is not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0084] The growth temperature for the P-type AlGaN trench filling growth is 1000-1100℃, for example, it can be 1000℃, 1020℃, 1040℃, 1060℃, 1080℃ or 1100℃, etc., but is not limited to the listed values. Other unlisted values ​​within this range also meet the requirements.

[0085] The growth pressure for the P-type AlGaN trench filling growth is 300-500 mbar, for example, it can be 300 mbar, 350 mbar, 400 mbar, 450 mbar or 500 mbar, but is not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0086] The doping concentration of the P-type AlGaN layer obtained by the P-type AlGaN trench filling growth is 1×10⁻⁶. 17 -1×10 18 atom / cm 3 For example, it could be 1×10 17 atom / cm 3 2×10 17 atom / cm 3 4×10 17 atom / cm 3 6×10 17 atom / cm 3 8×10 17 atom / cm 3 Or 1×10 18 atom / cm 3 The values ​​may include, but are not limited to, the listed values; other unlisted values ​​within this range also meet the requirements.

[0087] Wherein, when the base layer growth is P-type AlGaN layer growth, the trench filling growth is N-type GaN trench filling growth.

[0088] The carrier gas used in the growth of the P-type AlGaN layer includes nitrogen.

[0089] The flow rate of the carrier gas used in the growth of the P-type AlGaN layer is 50-100 slm, for example, it can be 50 slm, 60 slm, 70 slm, 80 slm, 90 slm or 100 slm, etc., but is not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0090] The Ga source used in the growth of the P-type AlGaN layer includes TMGa.

[0091] The flow rate of the Ga source used in the growth of the P-type AlGaN layer is 100-500 sccm, for example, it can be 100 sccm, 200 sccm, 300 sccm, 400 sccm or 500 sccm, but is not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0092] The nitrogen source used in the growth of the P-type AlGaN layer includes ammonia.

[0093] The nitrogen source flow rate used in the growth of the P-type AlGaN layer is 10-50 slm, for example, it can be 10 slm, 20 slm, 30 slm, 40 slm or 50 slm, but is not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0094] The aluminum source used in the growth of the P-type AlGaN layer includes TMAl.

[0095] The flow rate of the aluminum source used in the growth of the P-type AlGaN layer is 50-200 sccm, for example, it can be 50 sccm, 60 sccm, 80 sccm, 100 sccm, 120 sccm, 140 sccm, 160 sccm, 180 sccm or 200 sccm, but is not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0096] The growth temperature of the P-type AlGaN layer is 1000-1100℃, for example, it can be 1000℃, 1020℃, 1040℃, 1060℃, 1080℃ or 1100℃, etc., but is not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0097] The growth pressure for growing the P-type AlGaN layer is 300-500 mbar, for example, it can be 300 mbar, 350 mbar, 400 mbar, 450 mbar or 500 mbar, but is not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0098] The doping concentration of the P-type AlGaN layer grown from the P-type AlGaN layer is 1×10⁻⁶. 17 -1×10 18 atom / cm 3 For example, it could be 1×10 17 atom / cm 3 2×10 17 atom / cm 3 4×10 17 atom / cm 3 6×10 17 atom / cm 3 8×10 17 atom / cm 3 Or 1×10 18 atom / cm 3 The values ​​may include, but are not limited to, the listed values; other unlisted values ​​within this range also meet the requirements.

[0099] The carrier gas used in the N-type GaN trench filling growth includes nitrogen.

[0100] The flow rate of the carrier gas used in the N-type GaN trench filling growth is 50-100 slm, for example, it can be 50 slm, 60 slm, 70 slm, 80 slm, 90 slm or 100 slm, etc., but is not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0101] The Ga source used in the N-type GaN trench filling growth includes TMGa.

[0102] The flow rate of the Ga source used in the N-type GaN trench filling growth is 100-500 sccm, for example, it can be 100 sccm, 200 sccm, 300 sccm, 400 sccm or 500 sccm, but is not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0103] The nitrogen source used in the N-type GaN trench filling growth includes ammonia.

[0104] The flow rate of the nitrogen source used in the N-type GaN trench filling growth is 10-50 slm, for example, it can be 10 slm, 20 slm, 30 slm, 40 slm or 50 slm, but is not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0105] The silicon source used in the N-type GaN trench filling growth includes silane.

[0106] The flow rate of the silicon source used in the N-type GaN trench filling growth is 50-100 sccm, for example, it can be 50 sccm, 60 sccm, 70 sccm, 80 sccm, 90 sccm or 100 sccm, but is not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0107] The growth temperature for the N-type GaN trench filling growth is 1000-1100℃, for example, it can be 1000℃, 1020℃, 1040℃, 1060℃, 1080℃ or 1100℃, etc., but is not limited to the listed values. Other unlisted values ​​within this range also meet the requirements.

[0108] The growth pressure for the N-type GaN trench filling growth is 50-600 mbar, for example, it can be 50 mbar, 60 mbar, 80 mbar, 100 mbar, 200 mbar, 300 mbar, 400 mbar, 500 mbar or 600 mbar, but is not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0109] The doping concentration in the N-type GaN layer obtained by the N-type GaN trench filling growth is 1×10⁻⁶. 17 -1×10 18 atom / cm 3 For example, it could be 1×10 17 atom / cm 3 2×10 17 atom / cm 3 4×10 17 atom / cm 3 6×10 17 atom / cm 3 8×10 17 atom / cm 3 Or 1×10 18 atom / cm 3 The values ​​may include, but are not limited to, the listed values; other unlisted values ​​within this range also meet the requirements.

[0110] The thickness of the base layer obtained by the growth of the base layer is 5-20μm, for example, it can be 5μm, 6μm, 8μm, 10μm, 12μm, 14μm, 16μm, 18μm or 20μm, but is not limited to the listed values. Other unlisted values ​​within this range also meet the requirements.

[0111] The etching method for the base layer trenches is mask etching.

[0112] The sidewall inclination angle of the groove obtained by etching the base layer is 86-90°, for example, it can be 86°, 87°, 88°, 89° or 90°, but is not limited to the listed values. Other unlisted values ​​within this range also meet the requirements.

[0113] The depth of the grooves obtained by etching the base layer is 5-20μm, for example, it can be 5μm, 6μm, 8μm, 10μm, 12μm, 14μm, 16μm, 18μm or 20μm, but is not limited to the listed values. Other unlisted values ​​within this range also meet the requirements.

[0114] The width of the grooves obtained by etching the base layer is 2-2.5 μm, for example, it can be 2 μm, 2.1 μm, 2.2 μm, 2.3 μm, 2.4 μm or 2.5 μm, but is not limited to the listed values. Other unlisted values ​​within this range also meet the requirements.

[0115] In this invention, if the filling height exceeds the groove depth after the groove is filled, polishing or other methods can be used to remove the portion exceeding the groove depth.

[0116] The carrier gas used in the growth of the GaN channel layer includes nitrogen.

[0117] The flow rate of the carrier gas used in the growth of the GaN channel layer is 50-100 slm, for example, it can be 50 slm, 60 slm, 70 slm, 80 slm, 90 slm or 100 slm, etc., but is not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0118] The Ga source used in the growth of the GaN channel layer includes TMGa.

[0119] The flow rate of the Ga source used in the growth of the GaN channel layer is 100-200 sccm, for example, it can be 100 sccm, 120 sccm, 140 sccm, 160 sccm, 180 sccm or 200 sccm, but is not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0120] The nitrogen source used in the growth of the GaN channel layer includes ammonia.

[0121] The flow rate of the nitrogen source used in the GaN channel layer growth is 10-50 slm, for example, it can be 10 slm, 20 slm, 30 slm, 40 slm or 50 slm, but is not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0122] The growth temperature of the GaN channel layer is 1100-1120℃, for example, it can be 1100℃, 1105℃, 1110℃, 1115℃ or 1120℃, but is not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0123] The growth pressure for growing the GaN channel layer is 100-200 mbar, for example, it can be 100 mbar, 120 mbar, 140 mbar, 160 mbar, 180 mbar or 200 mbar, but is not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0124] The GaN channel layer grown therefrom has a diameter of 50-200nm, such as 50nm, 50nm, 60nm, 80nm, 100nm, 120nm, 140nm, 160nm, 180nm or 200nm, but is not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0125] The carrier gas used in the growth of the AlN insertion layer includes nitrogen.

[0126] The flow rate of the carrier gas used in the growth of the AlN insertion layer is 50-100 slm, for example, it can be 50 slm, 60 slm, 70 slm, 80 slm, 90 slm or 100 slm, etc., but is not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0127] The aluminum source used in the growth of the AlN insertion layer includes TMAl.

[0128] The flow rate of the aluminum source used in the growth of the AlN insertion layer is 40-60 sccm, for example, it can be 40 sccm, 45 sccm, 50 sccm, 55 sccm or 60 sccm, but is not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0129] The nitrogen source used in the growth of the AlN insertion layer includes ammonia.

[0130] The flow rate of the nitrogen source used in the growth of the AlN insertion layer is 1-5 slm, for example, it can be 1 slm, 2 slm, 3 slm, 4 slm or 5 slm, but is not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0131] The growth temperature of the AlN insertion layer is 1100-1120℃, for example, it can be 1100℃, 1105℃, 1110℃, 1115℃ or 1120℃, but is not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0132] The growth pressure for growing the AlN insertion layer is 100-200 mbar, for example, it can be 100 mbar, 120 mbar, 140 mbar, 160 mbar, 180 mbar or 200 mbar, but is not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0133] The thickness of the AlN insertion layer obtained by growing the AlN insertion layer is 1-1.5nm, for example, it can be 1nm, 1.1nm, 1.2nm, 1.3nm, 1.4nm or 1.5nm, but is not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0134] The carrier gas used in the growth of the AlGaN barrier layer includes nitrogen.

[0135] The flow rate of the carrier gas used in the growth of the AlGaN barrier layer is 50-100 slm, for example, it can be 50 slm, 60 slm, 70 slm, 80 slm, 90 slm or 100 slm, etc., but is not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0136] The Ga source used for growing the AlGaN barrier layer includes TMGa.

[0137] The flow rate of the Ga source used for growing the AlGaN barrier layer is 50-100 sccm, for example, it can be 50 sccm, 60 sccm, 70 sccm, 80 sccm, 90 sccm or 100 sccm, but is not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0138] The nitrogen source used for growing the AlGaN barrier layer includes ammonia.

[0139] The nitrogen source flux used for growing the AlGaN barrier layer is 1-5 slm, for example, it can be 1 slm, 2 slm, 3 slm, 4 slm or 5 slm, but is not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0140] The aluminum source used for growing the AlGaN barrier layer includes TMAl.

[0141] The flow rate of the aluminum source used for growing the AlGaN barrier layer is 50-200 sccm, for example, it can be 50 slm, 60 slm, 80 slm, 100 slm, 120 slm, 140 slm, 160 slm, 180 slm or 200 slm, but is not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0142] The growth temperature of the AlGaN barrier layer is 1100-1120℃, for example, it can be 1100℃, 1105℃, 1110℃, 1115℃ or 1120℃, but is not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0143] The growth pressure for growing the AlGaN barrier layer is 100-200 mbar, for example, it can be 100 mbar, 120 mbar, 140 mbar, 160 mbar, 180 mbar or 200 mbar, but is not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0144] The thickness of the AlGaN barrier layer obtained by growing the AlGaN barrier layer is 20-30nm, for example, it can be 20nm, 22nm, 24nm, 26nm, 28nm or 30nm, etc., but is not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0145] The carrier gas used for growing the GaN capping layer includes nitrogen.

[0146] The flow rate of the carrier gas used for growing the GaN capping layer is 50-100 slm, for example, it can be 50 slm, 60 slm, 70 slm, 80 slm, 90 slm or 100 slm, but is not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0147] The Ga source used for growing the GaN capping layer includes TMGa.

[0148] The flow rate of Ga primary used for growing the GaN capping layer is 30-60 sccm, for example, it can be 30 sccm, 35 sccm, 40 sccm, 45 sccm, 50 sccm, 55 sccm or 60 sccm, but is not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0149] The nitrogen source used for growing the GaN capping layer includes ammonia.

[0150] The nitrogen source flow rate used for growing the GaN capping layer is 1-5 slm, for example, it can be 1 slm, 2 slm, 3 slm, 4 slm or 5 slm, but is not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0151] The growth temperature of the GaN capping layer is 1110-1120℃, for example, it can be 1100℃, 1105℃, 1110℃, 1115℃ or 1120℃, but is not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0152] The growth pressure of the GaN capping layer is 100-200 mbar, for example, it can be 100 mbar, 120 mbar, 140 mbar, 160 mbar, 180 mbar or 200 mbar, but is not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0153] The thickness of the GaN capping layer grown therefrom is 10-20nm, for example, it can be 10nm, 12nm, 14nm, 16nm, 18nm or 20nm, etc., but is not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0154] Furthermore, to illustrate the excellent voltage withstand performance achievable by the GaN-based HEMT epitaxial wafer provided by this invention, the following practical example is provided for illustrative purposes:

[0155] Example 1

[0156] This embodiment provides a GaN-based HEMT epitaxial wafer, such as Figure 2 The above includes:

[0157] The substrate, from bottom to top, consists of a nucleation layer, a high-resistivity layer, a channel layer, an insertion layer, a barrier layer, and a capping layer.

[0158] The nucleation layer is an 18nm AlN nucleation layer;

[0159] The high-resistivity layer comprises alternating P-type AlGaN layers and N-type GaN layers arranged perpendicular to the direction in which the high-resistivity layer is set; the high-resistivity layer comprises an N-type GaN layer with a first groove and a P-type AlGaN layer disposed within the first groove; the thickness of the N-type GaN layer with the first groove is 10 μm; the depth of the first groove is 8 μm; the width of the first groove is 2.2 μm; the thickness of the P-type AlGaN layer disposed within the first groove is equal to the depth of the first groove;

[0160] The channel layer is a GaN channel layer with a thickness of 100 nm;

[0161] The insertion layer is an AlN insertion layer with a thickness of 1.2 nm;

[0162] The barrier layer is an AlGaN barrier layer with a thickness of 25 nm.

[0163] The capping layer is a GaN capping layer with a thickness of 15 nm.

[0164] The preparation process is as follows:

[0165] AlN nucleation layer growth, P-type AlGaN-N-type GaN high-resistivity layer growth, GaN channel layer growth, AlN insertion layer growth, AlGaN barrier layer growth and GaN capping layer growth are performed sequentially on the substrate to obtain GaN-based HEMT epitaxial wafer.

[0166] The growth temperature of the AlN nucleation layer is 800℃; the growth pressure of the AlN nucleation layer is 150 mbr.

[0167] The growth of the P-type AlGaN-N-type GaN high-resistivity layer consists of sequential substrate growth, substrate trench etching, and trench filling growth.

[0168] When the base layer growth is N-type GaN layer growth, the trench filling growth is P-type AlGaN trench filling growth;

[0169] The carrier gas used in the growth of the N-type GaN layer is nitrogen; the flow rate of the carrier gas used in the growth of the N-type GaN layer is 60 slm; the Ga source used in the growth of the N-type GaN layer is TMGa; the flow rate of the Ga source used in the growth of the N-type GaN layer is 200 sccm; the nitrogen source used in the growth of the N-type GaN layer is ammonia; the flow rate of the nitrogen source used in the growth of the N-type GaN layer is 20 slm; the silicon source used in the growth of the N-type GaN layer is silane; the flow rate of the silicon source used in the growth of the N-type GaN layer is 80 sccm; the growth temperature of the N-type GaN layer is 1050℃; the growth pressure of the N-type GaN layer is 300 mabr; and the doping concentration of the N-type GaN layer obtained by the growth of the N-type GaN layer is 4 × 10⁻⁶. 17 atom / cm 3 ;

[0170] The carrier gas used in the P-type AlGaN trench filling growth is nitrogen; the flow rate of the carrier gas used in the P-type AlGaN trench filling growth is 60 slm; the Ga source used in the P-type AlGaN trench filling growth is TMGa; the flow rate of the Ga source used in the P-type AlGaN trench filling growth is 300 sccm; the nitrogen source used in the P-type AlGaN trench filling growth is ammonia; the flow rate of the nitrogen source used in the P-type AlGaN trench filling growth is 30 slm; the aluminum source used in the P-type AlGaN trench filling growth is TMAl; the flow rate of the aluminum source used in the P-type AlGaN trench filling growth is 100 sccm; the growth temperature of the P-type AlGaN trench filling growth is 1050℃; the growth pressure of the P-type AlGaN trench filling growth is 400 mbar; and the doping concentration of the P-type AlGaN layer obtained by the P-type AlGaN trench filling growth is 4 × 10⁻⁶. 17 atom / cm 3 ;

[0171] The etching method for the base layer trench is mask etching; the sidewall inclination angle of the trench obtained by the base layer trench etching is 88°;

[0172] The carrier gas used in the GaN channel layer growth is nitrogen; the flow rate of the carrier gas used in the GaN channel layer growth is 60 slm; the Ga source used in the GaN channel layer growth is TMGa; the flow rate of the Ga source used in the GaN channel layer growth is 150 sccm; the nitrogen source used in the GaN channel layer growth is ammonia; the flow rate of the nitrogen source used in the GaN channel layer growth is 30 slm; the growth temperature of the GaN channel layer growth is 1110℃; the growth pressure of the GaN channel layer growth is 150 mbar; and the GaN channel layer obtained by the growth is 100 nm.

[0173] The carrier gas used in the AlN insertion layer growth is nitrogen; the flow rate of the carrier gas used in the AlN insertion layer growth is 60 slm; the aluminum source used in the AlN insertion layer growth is TMAl; the flow rate of the aluminum source used in the AlN insertion layer growth is 50 sccm; the nitrogen source used in the AlN insertion layer growth is ammonia; the flow rate of the nitrogen source used in the AlN insertion layer growth is 2 slm; the growth temperature of the AlN insertion layer growth is 1110℃; and the growth pressure of the AlN insertion layer growth is 150 mbar.

[0174] The carrier gas used in the growth of the AlGaN barrier layer is nitrogen; the flow rate of the carrier gas used in the growth of the AlGaN barrier layer is 60 slm; the Ga source used in the growth of the AlGaN barrier layer is TMGa; the flow rate of the Ga source used in the growth of the AlGaN barrier layer is 60 sccm; the nitrogen source used in the growth of the AlGaN barrier layer is ammonia; the flow rate of the nitrogen source used in the growth of the AlGaN barrier layer is 2 slm; the aluminum source used in the growth of the AlGaN barrier layer is TMAl; the flow rate of the aluminum source used in the growth of the AlGaN barrier layer is 100 sccm; the growth temperature of the AlGaN barrier layer is 1110℃; and the growth pressure of the AlGaN barrier layer is 150 mbar.

[0175] The carrier gas used for GaN capping layer growth is nitrogen; the flow rate of the carrier gas used for GaN capping layer growth is 60 slm; the Ga source used for GaN capping layer growth is TMGa; the flow rate of the Ga source used for GaN capping layer growth is 40 sccm; the nitrogen source used for GaN capping layer growth is ammonia; the flow rate of the nitrogen source used for GaN capping layer growth is 2 slm; the growth temperature of GaN capping layer growth is 1114℃; and the growth pressure of GaN capping layer growth is 150 mbar.

[0176] Example 2

[0177] This embodiment provides a GaN-based HEMT epitaxial wafer, such as Figure 3 As shown, it includes:

[0178] The substrate, from bottom to top, consists of a nucleation layer, a high-resistivity layer, a channel layer, an insertion layer, a barrier layer, and a capping layer.

[0179] The nucleation layer is a 17nm AlN nucleation layer;

[0180] The high-resistivity layer comprises alternating P-type AlGaN layers and N-type GaN layers arranged perpendicular to the direction in which the high-resistivity layer is set; the high-resistivity layer comprises a P-type AlGaN layer with a second groove and an N-type GaN layer disposed within the second groove; the thickness of the P-type AlGaN layer with the second groove is 15 μm; the depth of the second groove is 10 μm; the width of the second groove is 2.4 μm; the thickness of the N-type GaN layer disposed within the second groove is equal to the depth of the second groove;

[0181] The channel layer is a GaN channel layer with a thickness of 150 nm;

[0182] The insertion layer is an AlN insertion layer with a thickness of 1.4 nm;

[0183] The barrier layer is an AlGaN barrier layer with a thickness of 28 nm;

[0184] The capping layer is a GaN capping layer with a thickness of 18 nm.

[0185] The preparation process is as follows:

[0186] AlN nucleation layer growth, P-type AlGaN-N-type GaN high-resistivity layer growth, GaN channel layer growth, AlN insertion layer growth, AlGaN barrier layer growth and GaN capping layer growth are performed sequentially on the substrate to obtain GaN-based HEMT epitaxial wafer.

[0187] The growth temperature of the AlN nucleation layer is 1000℃; the growth pressure of the AlN nucleation layer is 100 mbr.

[0188] The growth of the P-type AlGaN-N-type GaN high-resistivity layer consists of sequential substrate growth, substrate trench etching, and trench filling growth.

[0189] When the base layer is grown as a P-type AlGaN layer, the trench filling growth is an N-type GaN trench filling growth.

[0190] The carrier gas used in the growth of the P-type AlGaN layer is nitrogen; the flow rate of the carrier gas used in the growth of the P-type AlGaN layer is 80 slm; the Ga source used in the growth of the P-type AlGaN layer is TMGa; the flow rate of the Ga source used in the growth of the P-type AlGaN layer is 300 sccm; the nitrogen source used in the growth of the P-type AlGaN layer is ammonia; the flow rate of the nitrogen source used in the growth of the P-type AlGaN layer is 30 slm; the aluminum source used in the growth of the P-type AlGaN layer is TMAl; the flow rate of the aluminum source used in the growth of the P-type AlGaN layer is 100 sccm; the growth temperature of the P-type AlGaN layer is 1080℃; the growth pressure of the P-type AlGaN layer is 400 mbar; and the doping concentration of the P-type AlGaN layer obtained by the growth of the P-type AlGaN layer is 7 × 10⁻⁶. 17 atom / cm 3 ;

[0191] The carrier gas used in the N-type GaN trench filling growth is nitrogen; the flow rate of the carrier gas used in the N-type GaN trench filling growth is 80 slm; the Ga source used in the N-type GaN trench filling growth is TMGa; the flow rate of the Ga source used in the N-type GaN trench filling growth is 400 sccm; the nitrogen source used in the N-type GaN trench filling growth is ammonia; the flow rate of the nitrogen source used in the N-type GaN trench filling growth is 40 slm; the silicon source used in the N-type GaN trench filling growth is silane; the flow rate of the silicon source used in the N-type GaN trench filling growth is 80 sccm; the growth temperature of the N-type GaN trench filling growth is 1080℃; the growth pressure of the N-type GaN trench filling growth is 300 mabr; and the doping concentration of the N-type GaN layer obtained by the N-type GaN trench filling growth is 7 × 10⁻⁶. 17 atom / cm 3 ;

[0192] The etching method for the base layer trench is mask etching, and the sidewall inclination angle of the trench obtained by the etching is 87°.

[0193] The carrier gas used in the GaN channel layer growth is nitrogen; the flow rate of the carrier gas used in the GaN channel layer growth is 80 slm; the Ga source used in the GaN channel layer growth is TMGa; the flow rate of the Ga source used in the GaN channel layer growth is 180 sccm; the nitrogen source used in the GaN channel layer growth is ammonia; the flow rate of the nitrogen source used in the GaN channel layer growth is 40 slm; the growth temperature of the GaN channel layer growth is 1115℃; the growth pressure of the GaN channel layer growth is 180 mbar; and the GaN channel layer obtained by the growth is 150 nm.

[0194] The carrier gas used in the AlN insertion layer growth is nitrogen; the flow rate of the carrier gas used in the AlN insertion layer growth is 80 slm; the aluminum source used in the AlN insertion layer growth is TMAl; the flow rate of the aluminum source used in the AlN insertion layer growth is 55 sccm; the nitrogen source used in the AlN insertion layer growth is ammonia; the flow rate of the nitrogen source used in the AlN insertion layer growth is 3 slm; the growth temperature of the AlN insertion layer growth is 1115℃; and the growth pressure of the AlN insertion layer growth is 180 mbar.

[0195] The carrier gas used in the growth of the AlGaN barrier layer is nitrogen; the flow rate of the carrier gas used in the growth of the AlGaN barrier layer is 80 slm; the Ga source used in the growth of the AlGaN barrier layer is TMGa; the flow rate of the Ga source used in the growth of the AlGaN barrier layer is 80 sccm; the nitrogen source used in the growth of the AlGaN barrier layer is ammonia; the flow rate of the nitrogen source used in the growth of the AlGaN barrier layer is 3 slm; the aluminum source used in the growth of the AlGaN barrier layer is TMAl; the flow rate of the aluminum source used in the growth of the AlGaN barrier layer is 150 sccm; the growth temperature of the AlGaN barrier layer is 1115℃; and the growth pressure of the AlGaN barrier layer is 180 mbar.

[0196] The carrier gas used for GaN capping layer growth is nitrogen; the flow rate of the carrier gas used for GaN capping layer growth is 80 slm; the Ga source used for GaN capping layer growth is TMGa; the flow rate of the Ga source used for GaN capping layer growth is 50 sccm; the nitrogen source used for GaN capping layer growth is ammonia; the flow rate of the nitrogen source used for GaN capping layer growth is 3 slm; the growth temperature of GaN capping layer growth is 1117℃; and the growth pressure of GaN capping layer growth is 180 mbar.

[0197] Example 3

[0198] This embodiment provides a GaN-based HEMT epitaxial wafer, such as Figure 4 The above includes:

[0199] The substrate, from bottom to top, consists of a nucleation layer, a high-resistivity layer, a channel layer, an insertion layer, a barrier layer, and a capping layer.

[0200] The nucleation layer is a 15nm AlN nucleation layer;

[0201] The high-resistivity layer comprises alternating P-type AlGaN layers and N-type GaN layers arranged perpendicular to the direction in which the high-resistivity layer is set; the high-resistivity layer comprises an N-type GaN layer with a first groove and a P-type AlGaN layer disposed within the first groove; the thickness of the N-type GaN layer with the first groove is 5 μm; the depth of the first groove is 5 μm; the width of the first groove is 2 μm; the thickness of the P-type AlGaN layer disposed within the first groove is equal to the depth of the first groove;

[0202] The channel layer is a GaN channel layer with a thickness of 50 nm;

[0203] The insertion layer is an AlN insertion layer with a thickness of 1.5 nm;

[0204] The barrier layer is an AlGaN barrier layer with a thickness of 20 nm;

[0205] The capping layer is a GaN capping layer with a thickness of 20 nm.

[0206] The preparation process is as follows:

[0207] AlN nucleation layer growth, P-type AlGaN-N-type GaN high-resistivity layer growth, GaN channel layer growth, AlN insertion layer growth, AlGaN barrier layer growth and GaN capping layer growth are performed sequentially on the substrate to obtain GaN-based HEMT epitaxial wafer.

[0208] The growth temperature of the AlN nucleation layer is 600℃; the growth pressure of the AlN nucleation layer is 200 mbr.

[0209] The growth of the P-type AlGaN-N-type GaN high-resistivity layer consists of sequential substrate growth, substrate trench etching, and trench filling growth.

[0210] When the base layer growth is N-type GaN layer growth, the trench filling growth is P-type AlGaN trench filling growth;

[0211] The carrier gas used in the growth of the N-type GaN layer is nitrogen; the flow rate of the carrier gas used in the growth of the N-type GaN layer is 50 slm; the Ga source used in the growth of the N-type GaN layer is TMGa; the flow rate of the Ga source used in the growth of the N-type GaN layer is 100 sccm; the nitrogen source used in the growth of the N-type GaN layer is ammonia; the flow rate of the nitrogen source used in the growth of the N-type GaN layer is 10 slm; the silicon source used in the growth of the N-type GaN layer is silane; the flow rate of the silicon source used in the growth of the N-type GaN layer is 50 sccm; the growth temperature in the growth of the N-type GaN layer is 1000℃; the growth pressure in the growth of the N-type GaN layer is 50 mabr; and the doping concentration of the N-type GaN layer obtained by the growth of the N-type GaN layer is 1×10⁻⁶. 17 atom / cm 3 ;

[0212] The carrier gas used in the P-type AlGaN trench filling growth is nitrogen; the flow rate of the carrier gas used in the P-type AlGaN trench filling growth is 50 slm; the Ga source used in the P-type AlGaN trench filling growth is TMGa; the flow rate of the Ga source used in the P-type AlGaN trench filling growth is 100 sccm; the nitrogen source used in the P-type AlGaN trench filling growth is ammonia; the flow rate of the nitrogen source used in the P-type AlGaN trench filling growth is 10 slm; the aluminum source used in the P-type AlGaN trench filling growth is TMAl; the flow rate of the aluminum source used in the P-type AlGaN trench filling growth is 50 sccm; the growth temperature of the P-type AlGaN trench filling growth is 1000℃; the growth pressure of the P-type AlGaN trench filling growth is 500 mbar; and the doping concentration of the P-type AlGaN layer obtained by the P-type AlGaN trench filling growth is 1×10⁻⁶. 17 atom / cm 3 ;

[0213] The etching method for the base layer trench is mask etching; the sidewall inclination angle of the trench obtained by the base layer trench etching is 86°;

[0214] The carrier gas used in the GaN channel layer growth is nitrogen; the flow rate of the carrier gas used in the GaN channel layer growth is 50 slm; the Ga source used in the GaN channel layer growth is TMGa; the flow rate of the Ga source used in the GaN channel layer growth is 100 sccm; the nitrogen source used in the GaN channel layer growth is ammonia; the flow rate of the nitrogen source used in the GaN channel layer growth is 10 slm; the growth temperature of the GaN channel layer growth is 1100℃; and the growth pressure of the GaN channel layer growth is 100 mbar.

[0215] The carrier gas used in the AlN insertion layer growth is nitrogen; the flow rate of the carrier gas used in the AlN insertion layer growth is 50 slm; the aluminum source used in the AlN insertion layer growth is TMAl; the flow rate of the aluminum source used in the AlN insertion layer growth is 40 sccm; the nitrogen source used in the AlN insertion layer growth is ammonia; the flow rate of the nitrogen source used in the AlN insertion layer growth is 1 slm; the growth temperature of the AlN insertion layer growth is 1100℃; and the growth pressure of the AlN insertion layer growth is 100 mbar.

[0216] The carrier gas used in the growth of the AlGaN barrier layer is nitrogen; the flow rate of the carrier gas used in the growth of the AlGaN barrier layer is 50 slm; the Ga source used in the growth of the AlGaN barrier layer is TMGa; the flow rate of the Ga source used in the growth of the AlGaN barrier layer is 50 sccm; the nitrogen source used in the growth of the AlGaN barrier layer is ammonia; the flow rate of the nitrogen source used in the growth of the AlGaN barrier layer is 1 slm; the aluminum source used in the growth of the AlGaN barrier layer is TMAl; the flow rate of the aluminum source used in the growth of the AlGaN barrier layer is 50 sccm; the growth temperature of the AlGaN barrier layer is 1100℃; and the growth pressure of the AlGaN barrier layer is 100 mbar.

[0217] The carrier gas used for GaN capping layer growth is nitrogen; the flow rate of the carrier gas used for GaN capping layer growth is 50 slm; the Ga source used for GaN capping layer growth is TMGa; the flow rate of the Ga source used for GaN capping layer growth is 30 sccm; the nitrogen source used for GaN capping layer growth is ammonia; the flow rate of the nitrogen source used for GaN capping layer growth is 1 slm; the growth temperature of GaN capping layer growth is 1110℃; and the growth pressure of GaN capping layer growth is 100 mbar.

[0218] Example 4

[0219] This embodiment provides a GaN-based HEMT epitaxial wafer, such as Figure 5 As shown, it includes:

[0220] The substrate, from bottom to top, consists of a nucleation layer, a high-resistivity layer, a channel layer, an insertion layer, a barrier layer, and a capping layer.

[0221] The nucleation layer is a 20nm AlN nucleation layer;

[0222] The high-resistivity layer comprises alternating P-type AlGaN layers and N-type GaN layers arranged perpendicular to the direction in which the high-resistivity layer is set; the high-resistivity layer comprises a P-type AlGaN layer with a second groove and an N-type GaN layer disposed within the second groove; the thickness of the P-type AlGaN layer with the second groove is 20 μm; the depth of the second groove is 20 μm; the width of the second groove is 2.5 μm; the thickness of the N-type GaN layer disposed within the second groove is equal to the depth of the second groove;

[0223] The channel layer is a GaN channel layer with a thickness of 200 nm;

[0224] The insertion layer is an AlN insertion layer with a thickness of 1 nm;

[0225] The barrier layer is an AlGaN barrier layer with a thickness of 30 nm;

[0226] The capping layer is a GaN capping layer with a thickness of 10 nm.

[0227] The preparation process is as follows:

[0228] AlN nucleation layer growth, P-type AlGaN-N-type GaN high-resistivity layer growth, GaN channel layer growth, AlN insertion layer growth, AlGaN barrier layer growth and GaN capping layer growth are performed sequentially on the substrate to obtain GaN-based HEMT epitaxial wafer.

[0229] The growth temperature of the AlN nucleation layer is 1200℃; the growth pressure of the AlN nucleation layer is 50 mbr.

[0230] The growth of the P-type AlGaN-N-type GaN high-resistivity layer consists of sequential substrate growth, substrate trench etching, and trench filling growth.

[0231] When the base layer is grown as a P-type AlGaN layer, the trench filling growth is an N-type GaN trench filling growth.

[0232] The carrier gas used in the growth of the P-type AlGaN layer is nitrogen; the flow rate of the carrier gas used in the growth of the P-type AlGaN layer is 100 slm; the Ga source used in the growth of the P-type AlGaN layer is TMGa; the flow rate of the Ga source used in the growth of the P-type AlGaN layer is 500 sccm; the nitrogen source used in the growth of the P-type AlGaN layer is ammonia; the flow rate of the nitrogen source used in the growth of the P-type AlGaN layer is 50 slm; the aluminum source used in the growth of the P-type AlGaN layer is TMAl; the flow rate of the aluminum source used in the growth of the P-type AlGaN layer is 200 sccm; the growth temperature of the P-type AlGaN layer is 1100℃; the growth pressure of the P-type AlGaN layer is 500 mbar; and the doping concentration of the P-type AlGaN layer obtained by the growth of the P-type AlGaN layer is 1×10⁻⁶. 18 atom / cm 3 ;

[0233] The carrier gas used in the N-type GaN trench filling growth is nitrogen; the flow rate of the carrier gas used in the N-type GaN trench filling growth is 100 slm; the Ga source used in the N-type GaN trench filling growth is TMGa; the flow rate of the Ga source used in the N-type GaN trench filling growth is 500 sccm; the nitrogen source used in the N-type GaN trench filling growth is ammonia; the flow rate of the nitrogen source used in the N-type GaN trench filling growth is 50 slm; the silicon source used in the N-type GaN trench filling growth is silane; the flow rate of the silicon source used in the N-type GaN trench filling growth is 100 sccm; the growth temperature of the N-type GaN trench filling growth is 1100℃; the growth pressure of the N-type GaN trench filling growth is 50 mabr; and the doping concentration of the N-type GaN layer obtained by the N-type GaN trench filling growth is 1×10⁻⁶. 18 atom / cm 3 ;

[0234] The etching method for the base layer trench is mask etching, and the sidewall inclination angle of the trench obtained by the etching is 90°.

[0235] The carrier gas used in the GaN channel layer growth is nitrogen; the flow rate of the carrier gas used in the GaN channel layer growth is 100 slm; the Ga source used in the GaN channel layer growth is TMGa; the flow rate of the Ga source used in the GaN channel layer growth is 200 sccm; the nitrogen source used in the GaN channel layer growth is ammonia; the flow rate of the nitrogen source used in the GaN channel layer growth is 50 slm; the growth temperature of the GaN channel layer growth is 1120℃; and the growth pressure of the GaN channel layer growth is 200 mbar.

[0236] The carrier gas used in the AlN insertion layer growth is nitrogen; the flow rate of the carrier gas used in the AlN insertion layer growth is 100 slm; the aluminum source used in the AlN insertion layer growth is TMAl; the flow rate of the aluminum source used in the AlN insertion layer growth is 60 sccm; the nitrogen source used in the AlN insertion layer growth is ammonia; the flow rate of the nitrogen source used in the AlN insertion layer growth is 5 slm; the growth temperature of the AlN insertion layer growth is 1120℃; and the growth pressure of the AlN insertion layer growth is 200 mbar.

[0237] The carrier gas used in the growth of the AlGaN barrier layer is nitrogen; the flow rate of the carrier gas used in the growth of the AlGaN barrier layer is 100 slm; the Ga source used in the growth of the AlGaN barrier layer is TMGa; the flow rate of the Ga source used in the growth of the AlGaN barrier layer is 100 sccm; the nitrogen source used in the growth of the AlGaN barrier layer is ammonia; the flow rate of the nitrogen source used in the growth of the AlGaN barrier layer is 5 slm; the aluminum source used in the growth of the AlGaN barrier layer is TMAl; the flow rate of the aluminum source used in the growth of the AlGaN barrier layer is 200 sccm; the growth temperature of the AlGaN barrier layer is 1120℃; and the growth pressure of the AlGaN barrier layer is 200 mbar.

[0238] The carrier gas used for GaN capping layer growth is nitrogen; the flow rate of the carrier gas used for GaN capping layer growth is 100 slm; the Ga source used for GaN capping layer growth is TMGa; the flow rate of the Ga source used for GaN capping layer growth is 60 sccm; the nitrogen source used for GaN capping layer growth is ammonia; the flow rate of the nitrogen source used for GaN capping layer growth is 5 slm; the growth temperature of GaN capping layer growth is 1120℃; and the growth pressure of GaN capping layer growth is 200 mbar.

[0239] Example 5

[0240] The only difference from Example 1 is that the thickness of the N-type GaN layer with the first groove is 2 μm.

[0241] Example 6

[0242] The only difference from Example 1 is that the thickness of the N-type GaN layer with the first groove is 30 μm.

[0243] The GaN-based HEMT epitaxial wafers obtained in the examples and comparative examples were tested for crystal quality using a high-resolution X-ray diffractometer (HRXRD), and their withstand voltage performance was tested using the T / CASAS 028—2023 Sub-6GHz GaN RF device reliability screening and acceptance method. The results are shown in Table 1 below.

[0244] Table 1

[0245] 002 Half-width (FWHM) 102 half-width (FWHM) <![CDATA[Vertical breakdown voltage ~ 850V @ 1μA / mm 2 > Example 1 295 696 1109 Example 2 306 703 1128 Example 3 290 701 1168 Example 4 302 707 1126 Example 5 524 956 903 Example 6 540 986 934

[0246] As shown in Table 1, the GaN-based HEMT epitaxial wafer provided by this invention, by designing a specific high-resistivity layer and utilizing a high-resistivity layer with a specific structure, obtains a high-resistivity layer with high crystal growth quality, which helps to avoid leakage current and thus improves the withstand voltage performance of the device.

[0247] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details of the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0248] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable way without contradiction. In order to avoid unnecessary repetition, this utility model will not describe the various possible combinations separately.

[0249] Furthermore, various different embodiments of this utility model can be combined in any way, as long as they do not violate the spirit of this utility model, they should also be regarded as the content disclosed by this utility model.

Claims

1. A GaN-based HEMT epitaxial wafer, characterized in that, The GaN-based HEMT epitaxial wafer includes: The substrate, from bottom to top, consists of a nucleation layer, a high-resistivity layer, a channel layer, an insertion layer, a barrier layer, and a capping layer. The nucleation layer is an AlN nucleation layer with a thickness of 15-20 nm; The high-resistivity layer includes a P-type AlGaN layer and an N-type GaN layer that are alternately arranged perpendicular to the direction in which the high-resistivity layer is set. The insertion layer is an AlN insertion layer with a thickness of 1-1.5 nm.

2. The GaN-based HEMT epitaxial wafer as described in claim 1, characterized in that, The high-resistivity layer is an N-type GaN layer with a first groove and a P-type AlGaN layer disposed within the first groove.

3. The GaN-based HEMT epitaxial wafer as described in claim 2, characterized in that, The thickness of the N-type GaN layer with the first groove is 5-20 μm; The depth of the first groove is 5-20 μm; The width of the first groove is 2-2.5 μm; The thickness of the P-type AlGaN layer disposed in the first groove is equal to the depth of the first groove.

4. The GaN-based HEMT epitaxial wafer as described in claim 1, characterized in that, The high-resistivity layer is a P-type AlGaN layer with a second groove and an N-type GaN layer disposed within the second groove.

5. The GaN-based HEMT epitaxial wafer as described in claim 4, characterized in that, The thickness of the P-type AlGaN layer with the second groove is 5-20 μm; The depth of the second groove is 5-20 μm; The width of the second groove is 2-2.5 μm; The thickness of the N-type GaN layer disposed in the second groove is equal to the depth of the second groove.

6. The GaN-based HEMT epitaxial wafer as described in claim 1, characterized in that, The channel layer is a GaN channel layer with a thickness of 50-200 nm.

7. The GaN-based HEMT epitaxial wafer as described in claim 1, characterized in that, The barrier layer is an AlGaN barrier layer with a thickness of 20-30 nm.

8. The GaN-based HEMT epitaxial wafer as described in claim 1, characterized in that, The capping layer is a GaN capping layer with a thickness of 10-20 nm.

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