A radio frequency GaN-based HEMT device with improved linearity and a method of manufacturing the same

Abstract

The application discloses a radio frequency GaN-based HEMT device with improved linearity and a preparation method thereof, which comprises, from bottom to top, a substrate, a nucleation layer, a buffer layer, a channel layer and a barrier layer, and a high electron mobility two-dimensional electron gas is formed near the interface between the channel layer and the barrier layer; the barrier layer and part of the channel layer are removed in a partial region to form a groove, a III-V nitride semiconductor material is grown in the groove to form a connected heavily doped region and a lightly doped region, and the lightly doped region faces a gate electrode; the bottom of a source electrode forms an ohmic contact with the upper surface of the heavily doped region, and the two-dimensional electron gas below the gate electrode forms a 2DEG-n- -GaN-n + -GaN structure through the 2DEG-n- -GaN-n structure formed by the heavily doped region and the lightly doped region between the gate electrode and the source electrode, so that the transconductance flatness and the cutoff frequency flatness of the radio frequency GaN-based HEMT device are improved, the dynamic input range, the input voltage swing and the output current swing of the device are widened, and the linearity of the device is improved.

Description

TECHNICAL FIELD

[0001] The application relates to a radio frequency GaN-based HEMT device, in particular to a radio frequency GaN-based HEMT device with improved linearity and a preparation method thereof, and belongs to the technical field of radio frequency GaN-based HEMT devices. BACKGROUND

[0002] Gallium nitride (GaN) is a wide-bandgap semiconductor material, which has significant advantages in radio frequency (RF) and microwave power amplifier applications, mainly due to its wide bandwidth, high frequency response and high voltage resistance characteristics. Especially in high frequency and high power applications, GaN devices show better performance than traditional silicon devices. This makes GaN an ideal choice for radio frequency power amplifiers in 4G LTE and 5G communication systems.

[0003] GaN HEMT (high electron mobility transistor) is a heterostructure device based on GaN, which usually forms a heterojunction with AlGaN (aluminum gallium nitride), and then forms a two-dimensional electron gas (2DEG) between the two materials. This two-dimensional electron gas layer provides very high electron mobility and electron saturation velocity, making GaN HEMT have high current driving capability and power output capability. These characteristics make GaN HEMT a strong candidate to replace silicon-based power amplifiers, especially in applications that require processing high frequency signals and high power output, such as wireless communication, radar and satellite communication.

[0004] Although GaN HEMT performs well in many aspects, it still faces an important challenge: nonlinear behavior. The nonlinear characteristics of GaN HEMT, especially under high frequency conditions, are particularly serious. Nonlinear characteristics can cause distortion between output signals and input signals, affecting the transmission efficiency and signal quality of the system. Especially at high power output, nonlinearity is more prominent, which can cause signal distortion and affect the performance of the communication system. The nonlinearity in GaN HEMT is mainly caused by parasitic effects inside the device. Specifically, these parasitic effects include source-drain resistance (RS) and drain-source resistance (RD), which are usually closely related to internal resistance, contact resistance and channel resistance of the device. By optimizing design and material quality, these effects can be effectively reduced to improve the performance and efficiency of GaN HEMT devices in high frequency and high power applications. Therefore, a radio frequency GaN-based HEMT device with improved linearity and a preparation method thereof are designed to solve the above problems. SUMMARY

[0005] The main purpose of the present application is to provide a radio frequency GaN-based HEMT device with improved linearity and a preparation method thereof, which solves the problem of narrow transconductance swing and poor linearity of existing GaN-based HENT devices.

[0006] The object of the present application can be achieved by adopting the following technical solutions:

[0007] The radio frequency GaN-based HEMT device with improved linearity is characterized in that a Schottky diode is inserted between the gate electrode and the source electrode, thereby improving the transconductance flatness and the cutoff frequency flatness of the radio frequency GaN-based HEMT device, widening the dynamic input range, input voltage swing and output current swing of the radio frequency GaN-based HEMT device, and improving the linearity of the radio frequency GaN-based HEMT device.

[0008] In order to solve the problems in the prior art, the present application provides a radio frequency GaN-based HEMT device with improved linearity and a preparation method thereof.

[0009] The radio frequency GaN-based HEMT device structure with improved linearity comprises, from bottom to top, a substrate, a nucleation layer, a buffer layer, a channel layer and a barrier layer, the buffer layer, the channel layer and the barrier layer being made of a ternary nitride material, and the ternary nitride semiconductor being a combination of any two or more of GaN, AlN and InN.

[0010] A two-dimensional electron gas (2DEG) is formed in the middle of the channel layer and the barrier layer, serving as a conductive channel of the HEMT device.

[0011] A gate electrode is arranged above the barrier layer, a drain electrode is arranged on one side of the gate electrode, and the barrier layer and part of the channel layer are removed in a partial region on the other side to form a groove, a ternary nitride semiconductor material is grown in the groove to form a connected heavily doped region and a lightly doped region, the heavily doped region being an N-type heavily doped n + , and the lightly doped region being an N-type lightly doped n - . The lightly doped region faces the gate electrode.

[0012] A source electrode is arranged on the side of the gate electrode opposite to the drain electrode, the bottom of the source electrode forms an ohmic contact with the upper surface of the heavily doped region, and the source electrode does not directly contact the two-dimensional electron gas. The two-dimensional electron gas below the gate electrode and the source electrode form a 2DEG-n + -GaN structure through the 2DEG formed by the heavily doped region and the lightly doped region, which is equivalent to inserting a Schottky diode between the gate electrode and the source electrode, thereby improving the linearity of the radio frequency GaN-based HEMT device.

[0013] In one embodiment of the present application, the drain electrode forms an ohmic contact with the two-dimensional electron gas of the channel layer, or forms a Schottky contact with the two-dimensional electron gas of the channel layer; the gate electrode forms a Schottky contact with the barrier layer, or forms a metal-insulator-semiconductor (MIS) structure with the barrier layer through an insulating medium layer under the gate electrode.

[0014] In one embodiment of the present application, a first passivation layer is above the barrier layer between the drain electrode and the gate electrode; a second passivation layer is above the group-III nitride material between the source electrode and the gate electrode. The material of the first passivation layer and the second passivation layer is one or a combination of SiN, SiO2, Al2O3.

[0015] In one embodiment of the present application, the material of the heavily doped region and the lightly doped region is GaN, or InGaN, or AlGaN, and the doping type is N-type, wherein the doping concentration of the heavily doped region is 1 x 1018cm-3, and the doping concentration of the lightly doped region is 1 x 1016cm-3. 18 -1 x 1018cm-3 21 cm-3 -3 -1 x 1016cm-3 16 -1 x 1018cm-3 18 cm-3 -3 The depth of the recess is 30-200 nm.

[0016] In one embodiment of the present application, the substrate is one of silicon, silicon carbide, sapphire, diamond.

[0017] In one embodiment of the present application, the material of the nucleation layer is AlN, and the thickness is 50 nm-300 nm. The nucleation layer is used to release the lattice mismatch stress and thermal stress between the buffer layer and the substrate.

[0018] In one embodiment of the present application, the material of the buffer layer is undoped GaN or AlGaN, and the thickness is 200 nm-5 μm.

[0019] In one embodiment of the present application, the material of the channel layer is GaN, InGaN or AlGaN, and the thickness is 50 nm-500 nm.

[0020] In one embodiment of the present application, the material of the barrier layer is AlGaN, InGaN or AlN, and the thickness is 5 nm-50 nm.

[0021] In one embodiment of the present application, the material of the drain electrode is any one or a combination of Ti / Al / Ni, Mo, Pt, Nb / Au.

[0022] In one embodiment of the present application, the material of the gate electrode and the source electrode is any one of Ni / Au, Ti / Au, TiN / Au or Ta / Au.

[0023] In one embodiment of the present application, the material of the first passivation layer and the second passivation layer is any one of Si3N4, SiO2 and Al2O3, and the thickness is 10-200 nm.

[0024] The present application also provides a preparation method of a radio frequency GaN-based HEMT device with improved linearity, characterized by comprising the following steps:

[0025] Step 1: surface cleaning of the substrate;

[0026] Step 2: sequentially growing a nucleation layer, a buffer layer, a channel layer and a barrier layer on the substrate;

[0027] Step 3: cleaning the epitaxial wafer and isolating the device;

[0028] Step 4: etching the barrier layer and the channel layer in a partial region to form a groove, and growing a III-V nitride material in the groove;

[0029] Step 5: ion implantation and high-temperature activation of the III-V nitride material in the groove to form a heavily doped region and a lightly doped region;

[0030] Step 6: growing a drain electrode above the barrier layer and performing annealing treatment to form an ohmic contact;

[0031] Step 7: depositing a source electrode above the heavily doped region to form an ohmic contact;

[0032] Step 8: depositing a gate electrode;

[0033] Step 9: depositing a first passivation layer and a second passivation layer.

[0034] In one embodiment of the present application, Step 4 is etching the barrier layer and the channel layer in a partial region to form a groove, and growing a lightly doped III-V nitride material in the groove;

[0035] In one embodiment of the present application, Step 5 is ion implantation and high-temperature activation of a partial region of the III-V nitride material on the side of the groove away from the gate electrode to form a heavily doped region, and the remaining lightly doped III-V nitride material in the groove forms a lightly doped region.

[0036] The present application has the following beneficial technical effects:

[0037] The application provides a radio frequency GaN-based HEMT device with improved linearity and a preparation method thereof, the structure can make the device exhibit the characteristics of wide transconductance and high linearity, solves the problem of relatively narrow transconductance swing of a conventional GaN-based HEMT device, stabilizes the control ability of the gate on the channel current, and makes the GaN-based HEMT device have higher linearity, which has great value for high-linearity radio frequency devices. In addition, the processing technology of the material is compatible with the existing mature technology, the cost is low, the material is easy to popularize, and the feasibility is high. BRIEF DESCRIPTION OF DRAWINGS

[0038] Figure 1 is a structural schematic diagram of a radio frequency GaN-based HEMT device with improved linearity according to the application;

[0039] Figure 2 is a flow schematic diagram of a preparation method of a radio frequency GaN-based HEMT device with improved linearity according to the application embodiment 2;

[0040] Figure 3 is a process schematic diagram of a preparation method of a radio frequency GaN-based HEMT device with improved linearity according to the application embodiment 3.

[0041] In the figure: 1. substrate; 2. nucleation layer; 3. buffer layer; 4. channel layer; 5. barrier layer; 6. drain electrode; 7. gate electrode; 8. source electrode; 9. heavily doped region; 10. lightly doped region; 11. first passivation layer; 12. second passivation layer; 81. groove. DETAILED DESCRIPTION

[0042] In order for those skilled in the art to be more clear and explicit about the technical solutions of the application, the application will be further described in detail below in combination with embodiments and drawings, but the embodiments of the application are not limited thereto.

[0043] Embodiment 1

[0044] The transconductance obtained by ignoring the series resistances RS and RD is the intrinsic transconductance gm*, and the transconductance of the saturation region of the HEMT device is

[0045]

[0046] When the series resistances RS and RD are not ignored, the voltage drop of IDS on the source-drain series resistances RS and RD is generated, and the RS and RD are derived from the channel resistances of the ungated channel regions between the gate-source and the gate-drain and the source-drain ohmic contact resistance RC.

[0047] The source resistance RS makes the effective gate voltage between the gate and the source decrease, which will affect the saturation region transconductance gm, and the drain resistance RD will increase the source-drain voltage VDSat when the current starts to saturate, but the VDS has no effect on the output current when VDS> VDSat, so the RD has no effect on gm.

[0048] Two adjacent grooves are arranged in sequence at the position right below the source electrode and the middle region between the source electrode and the gate electrode, the bottom ends of the grooves are located in the upper part of the channel layer, gallium nitride material is grown in the grooves, and by means of ion implantation, heavily doped n+ gallium nitride material is formed in the groove right below the source electrode, and lightly doped n- gallium nitride material is formed in the groove at the middle region between the source electrode and the gate electrode, the two-dimensional electron gas concentration is high, and it is considered as n + Doping, wherein n - The groove doping concentration is low, and a high resistance region is formed.

[0049] In this way, the two-dimensional electron gas below the gate electrode and the source electrode form a Schottky diode structure through the two doped grooves.

[0050] The structure can make the device exhibit the characteristics of wide transconductance and high linearity, solve the problem that the conventional GaN-based HEMT device has relatively narrow gm, make the device have flat gm, thereby stabilize the control ability of the gate to the channel current, and make the GaN-based HEMT device have higher linearity, which has great value for high linearity radio frequency devices.

[0051] The application discloses a GaN-based HEMT device with high linearity. Figure 1 As shown in the figure, the device sequentially comprises a substrate 1, a nucleation layer 2, a buffer layer 3, a channel layer 4 and a barrier layer 5 from bottom to top, the buffer layer 3, the channel layer 4 and the barrier layer 5 are ternary nitride materials, and the ternary nitride semiconductor is any two or more combinations of GaN, AlN and InN. A two-dimensional electron gas (2DEG) is formed in the middle of the channel layer 4 and the barrier layer 5, serving as a conductive channel of the HEMT device. A gate electrode 7 is arranged above the barrier layer 5, a drain electrode 6 is arranged on one side of the gate electrode 7, and the barrier layer 5 and part of the channel layer 4 are removed in a partial region on the other side, so as to form a groove 81, ternary nitride semiconductor material is grown in the groove 81, a connected heavily doped region 9 and a lightly doped region 10 are formed, wherein the heavily doped region 9 is N-type heavily doped n+, and the lightly doped region 10 is N-type lightly doped n-. The lightly doped region 10 faces the gate electrode. A source electrode 8 is arranged on the side of the gate electrode 7 opposite to the drain electrode 6, the bottom of the source electrode 8 forms an ohmic contact with the upper surface of the heavily doped region 9, and the source electrode 8 does not directly contact the two-dimensional electron gas. The two-dimensional electron gas below the gate electrode 7 and the source electrode 8 form a 2DEG-n--GaN-n + -GaN structure, which is equivalent to inserting a Schottky diode between the gate electrode 7 and the source electrode 8, thereby improving the linearity of the radio frequency GaN-based HEMT device.

[0052] Specifically, the drain electrode 6 directly forms an ohmic contact with the two-dimensional electron gas of the channel layer 4;

[0053] Specifically, the gate electrode 7 forms a Schottky contact with the barrier layer 5.

[0054] Specifically, the first passivation layer 11 is above the barrier layer 5 between the drain electrode 6 and the gate electrode 7; and the second passivation layer 12 is above the III-V nitride material between the source electrode 8 and the gate electrode 7.

[0055] The material of the first passivation layer (11) and the second passivation layer (12) is SiN.

[0056] Specifically, the material of the heavily doped region 9 and the lightly doped region 10 is GaN, or InGaN, or AlGaN, and the doping type is N-type, wherein the doping concentration of the heavily doped region 9 is 1×1018cm-3, and the doping concentration of the lightly doped region 10 is 1×1017cm-3. 18 -1×1018cm-3. 21 cm-3. -3 -1×1017cm-3. 16 cm-3. 18 cm-3. -3 The depth of the recess 81 is 30-200nm.

[0057] Preferably, the material of the heavily doped region 9 and the lightly doped region 10 is GaN, and the doping type is N-type, wherein the doping concentration of the heavily doped region 9 is 1×1018cm-3, and the doping concentration of the lightly doped region 10 is 5×1017cm-3. 20 cm-3. -3 . 173

[0058] Specifically, the depth of the recess 81 is 30-200nm.

[0059] Preferably, the depth of the recess 81 is 80nm.

[0060] Specifically, the substrate 1 is made of one of silicon, silicon carbide, sapphire, and diamond.

[0061] Preferably, the substrate 1 is made of silicon carbide.

[0062] Specifically, the material of the nucleation layer 2 is AlN, and the thickness is 50nm-300nm, and the nucleation layer 2 is used to release the lattice mismatch stress and thermal stress between the buffer layer 3 and the substrate.

[0063] Specifically, in an embodiment of the present application, the material of the buffer layer 3 is undoped GaN or AlGaN, and the thickness is 200nm-5μm.

[0064] Specifically, the material of the channel layer 4 is GaN, InGaN, or AlGaN, and the thickness is 50nm-500nm.

[0065] Specifically, the material of the barrier layer 5 is AlGaN, InGaN, or AlN, and the thickness is 5nm-50nm. ​

[0066] Specifically, the material of the drain electrode 6 is any one or a combination of more than one of Ti / Al / Ni, Mo, Pt, Nb / Au.

[0067] Specifically, the material of the gate electrode 7 and the source electrode 8 is any one of Ni / Au, Ti / Au, TiN / Au or Ta / Au.

[0068] Specifically, the material of the first passivation layer 11 and the second passivation layer 12 is any one of Si3N4, SiO2, Al2O3, and the thickness is 10-200 nm.

[0069] Embodiment 2

[0070] The present application provides a preparation method of a GaN-based HEMT device with high linearity, as shown in the following steps: Figure 2

[0071] Step 1: surface cleaning of the substrate 1;

[0072] Step 2: sequentially growing a nucleation layer 2, a buffer layer 3, a channel layer 4 and a barrier layer 5 on the substrate;

[0073] Step 3: cleaning the epitaxial wafer and isolating the device;

[0074] Step 4: etching the barrier layer 5 and part of the channel layer 4 to form a groove 81, and growing a III-V nitride material in the groove 81;

[0075] Step 5: ion implantation and high-temperature activation of the III-V nitride material in the groove 81 to form a heavily doped region 9 and a lightly doped region 10;

[0076] Step 6: growing a drain electrode 6 above the barrier layer 5 and performing annealing treatment to form an ohmic contact;

[0077] Step 7: depositing a source electrode 8 above the heavily doped region 9 to form an ohmic contact;

[0078] Step 8: depositing a gate electrode 7;

[0079] Step 9: depositing a first passivation layer 11 and a second passivation layer 12.

[0080] Embodiment 3

[0081] A preparation method of a GaN-based HEMT device with high linearity, as shown in the following steps: Figure 3

[0082] Step 1: surface cleaning of the selected 500 μm thick SiC substrate 1;

[0083] ​​Hydrogen is introduced into the reaction chamber at 1000℃ to remove the contaminants on the surface of the substrate 1 and form a micro-step structure on the surface of the substrate 1, so as to prepare for the growth of various epitaxial layers in subsequent epitaxial processes;

[0084] Step 2: A nucleation layer 2, a buffer layer 3, a channel layer 4 and a barrier layer 5 are sequentially grown on the substrate 1 by metal organic chemical vapor deposition (MOCVD);

[0085] The nucleation layer 2 is AlN with a thickness of 100 nm, the buffer layer 3 is GaN with a thickness of 1.2 μm, and the channel layer 4 is GaN with a thickness of 300 nm;

[0086] The barrier layer 5 is grown on the channel layer 4 by MOCVD;

[0087] The barrier layer 5 is AlGaN with a thickness of 20 nm and an Al component of 0.3;

[0088] Step 3: The epitaxial wafer is cleaned, and the device is isolated;

[0089] The cleaning of the epitaxial wafer mainly includes organic cleaning, inorganic cleaning and removal of the surface passivation layer. The sample is ultrasonically cleaned in acetone solution for 2 minutes, and then the sample is placed in ethanol solution for ultrasonic cleaning for 3 minutes to remove the residual acetone liquid on the surface of the sample. The sample is soaked in diluted HF solution for 1 minute to remove the surface oxide and inorganic contaminants, and finally the sample is rinsed with flowing deionized water and dried with a nitrogen gun. The removal of residual photoresist in the photoetch process, the cleaning of the sample surface before metal evaporation, etc. are also required;

[0090] The mesa isolation adopts a mesa isolation technology with low complexity, low cost and easy implementation. The etching gas is Cl2, and the etching depth is 400 nm;

[0091] Step 4: Etching is performed on part of the barrier layer 5 and the channel layer 4. A groove 81 is etched, GaN material is grown in the groove 81, and ion implantation is performed to dope the left and right regions of the groove 81, respectively.

[0092] Specifically, the region of the barrier layer 5 between the source electrode and the gate electrode is etched by reactive ion etching (RIE) to form a groove with a thickness of 100 nm.

[0093] Specifically, a low-damage Cl2 / BCl3 etching process is adopted, and the etching equipment is reactive ion etching (RIE). The etching rate is 2.5 nm / min, and the etching depth is 100 nm.

[0094] Specifically, the heavy doping region 9 is formed by ion implantation.+ Region, the doping concentration is 1x10 18 -1x10 21 cm -3 ; make the light doped region 10 light doped n - Region, the doping concentration is 1x10 13 -1x10 16 cm -3 ;

[0095] Step 5: growing the drain electrode 6 above the barrier layer 5 and annealing to form ohmic contact;

[0096] Specifically, four layers of metal are grown in the region by electron beam evaporation, using Ti / Al / Ni / Au, and the corresponding film thicknesses are 22nm / 150nm / 55nm / 45nm, and then rapid annealing is performed at a temperature of 880℃ in N2 for 30s to alloy and form ohmic contact;

[0097] Step 6: depositing the source electrode 8 directly above the heavily doped n+ region 9 on the left side of the groove and annealing to form ohmic contact between the source electrode and the heavily doped n + Region 9 on the left side of the groove;

[0098] Specifically, the source electrode 8 is made by selecting a metal with a high work function as the source metal, and in this embodiment, a Ni / Cr stacked metal is used, and rapid annealing is performed at 880℃ in N2 for 30s to form ohmic contact between the source electrode 8 and the n+ buried layer 9;

[0099] Step 7: depositing the gate electrode 7;

[0100] Specifically, the gate electrode 7 is usually made of a metal with a high work function as the gate metal, and in this embodiment, a Ni / Au stacked metal is used. The Ni / Au (50 / 150nm) double-layer metal is deposited using an electron beam evaporation device, and after the metal evaporation is complete, the sample is placed in an N2 atmosphere at 450℃ for rapid annealing for 5min to form a gate Schottky contact;

[0101] Step 8: preparing the first passivation layer 11 and the second passivation layer 12;

[0102] Specifically, a layer of Si3N4 film with a thickness of 150nm is deposited on the surface of the barrier layer using plasma enhanced chemical vapor deposition (PECVD).

[0103] The above is only a further embodiment of the present application, but the protection scope of the present application is not limited thereto, and any person skilled in the art can make equivalent replacements or changes within the scope disclosed by the present application according to the technical solutions and concepts of the present application, which are all within the protection scope of the present application.

Claims

1. A linearity-enhanced radio frequency GaN-based HEMT device, characterized by: The substrate (1), the nucleation layer (2), the buffer layer (3), the channel layer (4) and the barrier layer (5) are sequentially arranged from bottom to top; The buffer layer (3), the channel layer (4) and the barrier layer (5) are made of a group III nitride material, the group III nitride semiconductor is any two or more combinations of GaN, AlN and InN, a two-dimensional electron gas (2DEG) is formed between the channel layer (4) and the barrier layer (5) as a conductive channel of the HEMT device, a gate electrode (7) is arranged above the barrier layer (5), a drain electrode (6) is arranged on one side of the gate electrode (7), and the barrier layer (5) and part of the channel layer (4) are removed in a partial region on the other side to form a groove (81), a group III nitride semiconductor material is grown in the groove (81) to form a connected heavily doped region (9) and a lightly doped region (10), wherein the heavily doped region (9) is an N-type heavily doped n+, and the lightly doped region (10) is an N-type lightly doped n - The lightly doped region (10) faces the gate electrode, a source electrode (8) is arranged on the side of the gate electrode (7) opposite to the drain electrode (6), the bottom of the source electrode (8) forms an ohmic contact with the upper surface of the heavily doped region (9), the source electrode (8) does not directly contact the two-dimensional electron gas, and the two-dimensional electron gas below the gate electrode (7) forms a structure of 2DEG-n--GaN-n+-GaN with the source electrode (8) through the heavily doped region (9) and the lightly doped region (10), which is equivalent to inserting a Schottky diode between the gate electrode (7) and the source electrode (8).

2. A linearity-enhanced RF GaN-based HEMT device according to claim 1, characterized in that: The drain electrode (6) forms ohmic contact with the two-dimensional electron gas of the channel layer (4), or forms Schottky contact with the two-dimensional electron gas of the channel layer (4); The gate electrode (7) forms Schottky contact with the barrier layer (5) or forms metal-insulator-semiconductor (MIS) structure with the barrier layer (5) through a layer of insulating medium under the gate electrode (7).

3. The linearly improved radio frequency GaN-based HEMT device according to claim 1, wherein the first passivation layer (11) is arranged above the barrier layer (5) between the drain electrode (6) and the gate electrode (7). The second passivation layer (12) is arranged above the group-III nitride material between the source electrode (8) and the gate electrode (7), and the first passivation layer (11) and the second passivation layer (12) are made of one or a combination of SiN, SiO2 and Al2O3.

4. A linearly enhanced RF GaN-based HEMT device according to claim 1, the material of the heavily doped region (9) and the lightly doped region (10) is GaN, or InGaN, or AlGaN, and the doping type is N-type, wherein the heavily doped region (9) has a doping concentration of 1 x 1018 cm"3, and the lightly doped region (10) has a doping concentration of 1 x 1017 cm"3. 18 -1 x 1018 cm"3 21 -1 x 1017 cm"3 -3 -1 x 1018 cm"3 16 -1 x 1017 cm"3 18 -1 x 1018 cm"3 -3 -1 x 1017 cm"3 The depth of the groove (81) is 30-200 nm.

5. The linearity-enhanced RF GaN-based HEMT device of claim 1, wherein: The substrate (1) is made of one of silicon, silicon carbide, sapphire and diamond.

6. The linearity-enhanced radio-frequency GaN-based HEMT device of claim 1, wherein, The nucleation layer (2) is made of AlN and has a thickness of 50-300 nm, and is used to release the lattice mismatch stress and thermal stress between the buffer layer (3) and the substrate; The buffer layer (3) is made of undoped GaN or AlGaN and has a thickness of 200 nm to 5 μm; The channel layer (4) is made of GaN, InGaN or AlGaN and has a thickness of 50-500 nm; The barrier layer (5) is made of AlGaN, InGaN or AlN and has a thickness of 5-50 nm.

7. The linearity-enhanced radio-frequency GaN-based HEMT device of claim 1, wherein, The drain electrode (6) is made of any one or a combination of Ti / Al / Ni, Mo, Pt and Nb / Au. The gate electrode (7) and the source electrode (8) are made of any one of Ni / Au, Ti / Au, TiN / Au and Ta / Au. The first passivation layer (11) and the second passivation layer (12) are made of any one of Si3N4, SiO2 and Al2O3 and have a thickness of 10-200 nm.

8. A method for preparing a linearized RF GaN-based HEMT device according to any one of claims 1-7, characterized in that, The method comprises the following steps: Step 1: surface cleaning of the substrate (1); Step 2: sequentially growing the nucleation layer (2), the buffer layer (3), the channel layer (4) and the barrier layer (5) on the substrate; Step 3: cleaning the epitaxial wafer and isolating the device; Step 4: etching the barrier layer (5) and part of the channel layer (4) to form a groove (81), and growing group-III nitride material in the groove (81); Step 5: ion implantation and high-temperature activation of the group-III nitride material in the groove (81) to form a heavily doped region (9) and a lightly doped region (10); Step 6: growing the drain electrode (6) above the barrier layer (5) and performing annealing treatment to form ohmic contact; Step 7: depositing the source electrode (8) above the heavily doped region (9) to form ohmic contact; Step 8: depositing the gate electrode (7); Step 9: depositing the first passivation layer (11) and the second passivation layer (12).

9. The method of claim 8, wherein, Step 4: etching a part of the barrier layer (5) and the channel layer (4) to form a groove (81), and growing a lightly doped III-N material in the groove (81); Step 5: ion implantation and high-temperature activation in a part of the III-N material in the groove (81) away from the gate electrode to form a heavily doped region (9), and the remaining III-N material in the groove (81) forms a lightly doped region (10); The other steps are the same as those in claim 8.

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