阅读说明：本技术 一种基于第三代半导体GaN材料的HEMT外延器件及其生长方法 (HEMT epitaxial device based on third-generation semiconductor GaN material and growth method thereof ) 是由 王晓波 于 2021-08-05 设计创作，主要内容包括：本发明公开了一种基于第三代半导体GaN材料的HEMT外延器件,在基底上采用MOCVD技术进行异质外延生长；包括：从下至上依次层叠的基底、第一GaN层、耗尽高阻区、Al-(z)Ga-(1-z)N层、2DEG通道、AlN层、AlGaN层、第二GaN层。本发明采用GaN/Al-(x)Ga-(1-x)N-SL等组分渐变组合的超晶格结构,可以减小材料生长的应力,同时由于材料禁带宽度有基底向上逐步增加,使背景电子向低能量区移动,形成指向基底的内建电场,从而产生局部区域耗尽层,极大降低自由电子浓度,形成相对高阻区域,降低电流崩塌和漏电通道。(The invention discloses a HEMT epitaxial device based on a third-generation semiconductor GaN material, which adopts the MOCVD technology to carry out heteroepitaxial growth on a substrate; the method comprises the following steps: a substrate, a first GaN layer, a depletion high-resistance region and Al which are sequentially stacked from bottom to top z Ga 1‑z The GaN-based LED comprises an N layer, a 2DEG channel, an AlN layer, an AlGaN layer and a second GaN layer. The invention adopts GaN/Al x Ga 1‑x The superlattice structure with gradually-changed components such as N-SL (N-Long service life) and the like can reduce the stress of material growth, and simultaneously, as the forbidden band width of the material is gradually increased upwards by the substrate, background electrons move to a low-energy region to form a built-in electric field pointing to the substrate, so that a depletion layer in a local region is generated, and free electricity is greatly reducedSub-concentration, forming a relatively high resistance region, reducing current collapse and leakage paths.)

1. A HEMT epitaxial device based on a third-generation semiconductor GaN material is characterized in that a substrate is subjected to heteroepitaxial growth by adopting an MOCVD technology;

wherein, the HEMT epitaxial device includes: from belowA substrate, a first GaN layer, a depletion high-resistance region, and Al sequentially stacked on the substrate_zGa_1-zThe GaN-based LED comprises an N layer, a 2DEG channel, an AlN layer, an AlGaN layer and a second GaN layer.

2. A HEMT epitaxial device according to claim 1, wherein said substrate is any one of sapphire, silicon, GaN, AlN, SiC.

3. A HEMT epitaxial device according to claim 1, wherein said depletion high resistance region comprises, from bottom to top: GaN/Al_xGa_1-xN-SL layer, GaN/Al_yGa_1-yN-SL layer, GaN/Al_zGa_{1- z}N-SL layer and Al_aGa_1-aN/Al_zGa_1-zAnd an N-SL layer.

4. A HEMT epitaxial device based on third generation semiconductor GaN material according to claim 3, characterized in that the GaN/Al is_xGa_1-x0 in N-SL layer<x is less than or equal to 0.1, and the GaN/Al_xGa_1-xThe thickness of the N-SL layer is 40-200 nm;

the GaN/Al_yGa_1-y0.1 in N-SL layer<y is less than or equal to 0.2, and the GaN/Al_yGa_1-yThe thickness of the N-SL layer is 40-200 nm;

the GaN/Al_zGa_1-z0.2 in N-SL layer<z is less than or equal to 0.3, and the GaN/Al_zGa_1-zThe thickness of the N-SL layer is 40-200 nm;

the Al is_aGa_1-aN/Al_zGa_1-z0.1 in N-SL layer<a≤0.2，0.2<z is less than or equal to 0.3, and Al_aGa_1-aN/Al_zGa_1-zThe thickness of the N-SL layer is 40-200 nm.

5. A HEMT epitaxial device according to claim 1, wherein said 2DEG channel is a double 2DEG channel or a multiple 2DEG channel.

6. A HEMT epitaxial device based on third generation semiconductor GaN material according to claim 5, wherein the double 2DEG channel comprises, from bottom to top: a third GaN layer and an InAlN layer;

wherein the thickness of the third GaN layer is 100-300nm, and the thickness of the InAlN layer is 50-150 nm.

7. A HEMT epitaxial device based on third generation semiconductor GaN material according to claim 5, wherein the multiple 2DEG channels comprise, from bottom to top: an AlInGaN or InGaN layer, a third GaN layer and an InAlN layer;

the thickness of the AlInGaN or InGaN layer is 100-200nm, the thickness of the third GaN layer is 100-300nm, and the thickness of the InAlN layer is 50-150 nm.

8. A HEMT epitaxial device based on third generation semiconductor GaN material according to claim 4, characterized in that the Al is_zGa_1-zThe N layer is a gradient layer of Al component; the Al is_zGa_1-z0.2 in the N layer<z is less than or equal to 0.3, and Al_zGa_1-zThe Al component in the N layer gradually changes to 0, and the Al_zGa_1-zThe thickness of the N layer is 10-30 nm;

the AlGaN layer is a gradient layer of Al component; the Al composition in the AlGaN layer gradually becomes 0.

9. The HEMT epitaxial device of claim 4, wherein the thickness of the first GaN layer is 110-220 nm;

the AlN layer is 1-2nm thick; the thickness of the AlGaN layer is 20-50 nm; the thickness of the second GaN layer is 5-10 nm.

10. A method of growing a third generation semiconductor GaN material based HEMT epitaxial device according to any one of claims 1-9, comprising the steps of:

(1) cleaning a substrate by dilute hydrochloric acid and isopropanol, washing by water, then spin-drying, and baking in MOCVD equipment;

(2) introducing trimethyl gallium and ammonia gas to grow a first GaN layer on the substrate;

(3) introducing trimethyl aluminum, trimethyl gallium and ammonia gas to grow GaN/Al_xGa_1-xAn N-SL layer;

(4) introducing trimethyl aluminum, trimethyl gallium and ammonia gas to grow GaN/Al_yGa_1-yAn N-SL layer;

(5) introducing trimethyl aluminum, trimethyl gallium and ammonia gas to grow GaN/Al_zGa_1-zAn N-SL layer;

(6) introducing trimethyl aluminum, trimethyl gallium and ammonia gas to grow Al_aGa_1-aN/Al_zGa_1-zAn N-SL layer;

(7) introducing trimethylaluminum, trimethylgallium and ammonia gas, gradually decreasing the growth flow of the trimethylaluminum to 0sccm, keeping the source flow of the trimethylgallium unchanged, and growing Al with gradually changed Al components_zGa_1-zN layers;

(8) introducing trimethyl gallium and ammonia gas to grow a third GaN layer;

(9) introducing trimethyl aluminum, trimethyl indium and ammonia gas to grow an InAlN layer with the aluminum component of 0.82 and the indium component of 0.18;

(10) introducing trimethylaluminum and ammonia gas to grow an AlN layer;

(11) introducing trimethyl aluminum, trimethyl gallium and ammonia gas, setting the growth flow of trimethyl gallium to be constant, setting the source flow of trimethyl aluminum to gradually decrease to 0sccm from the growth of the layer to the end, and growing an AlGaN layer with gradually changed aluminum components;

(12) and introducing trimethyl gallium and ammonia gas to grow a second GaN layer to obtain the HEMT epitaxial device.

Technical Field

The invention relates to the technical field of novel semiconductors, in particular to a HEMT epitaxial device based on a third-generation semiconductor GaN material and a growth method thereof.

Background

Third generation wide bandgap semiconductors represented by gallium nitride (GaN) and aluminum nitride (AlN) are receiving wide attention due to their wide bandgap constant, higher electron mobility, strong radiation resistance, good breakdown field strength, high temperature resistance, etc., and heterojunction High Electron Mobility Transistors (HEMTs) (or heterojunction field effect transistors HFETs, modulation-doped field effect transistors MODFETs, hereinafter collectively referred to as HEMT chips) based on compound AlGaN/GaN are widely used in the semiconductor field. The chip has the characteristics of high reverse resistance-breakdown voltage, low forward on-resistance, high working frequency and the like, so that the requirements of a system on higher power, higher frequency and smaller-volume work of a semiconductor device can be met, along with the technological progress, the requirements on the performance and reliability of the HEMT chip are higher and higher, but the method and the structure of the epitaxial growth of the third-generation semiconductor material still have many problems at present;

one is as follows: increasing output current, increasing output power, and along with the expansion of application direction, the output current and power of the HMET need to be increased more, the current output of the HMET at present is increased in increasing 2DEG (two-dimensional electron gas) concentration, and the traditional double-channel or multi-channel 2DEG with double heterojunction structure, AlGaN/GaN/AlGaN/GaN, InAlN/GaN/InAlN/GaN, AlN/GaN/AlN/GaN or other heterojunction are alternately and sequentially arranged, the narrow bandgap materials at two sides of the structure have respective 2DEG, the directions of the built-in electric fields are the same, but 2DEG appears at two middle heterojunctions, and the directions of the built-in electric fields are opposite to those at two sides, although the current output can be increased by two channels or multi-channel 2DEG, the reverse electric field at the middle heterojunctions of the traditional two-channel structure can make the grid voltage control unstable and pinch-off current characteristics worse, the intermediate reverse electric field can impair the control of the gate to the current, which is detrimental to the overall performance.

The second step is as follows: high GaN background electron concentration causes a leakage channel and parasitic current, metal elements such as Fe, Cr, Mg and the like are introduced into the epitaxial growth of GaN to form deep energy level defects or provide holes to compensate residual carriers so as to obtain a GaN' layer with high resistance, although the high resistance of the GaN can be improved, the doping of the epitaxial layer is not easy to control, the material deterioration can be generated, meanwhile, impurities are introduced to reduce the mobility of the channel 2DEG, and the device characteristics are influenced, so that a new method is urgently needed to be improved.

And thirdly: the most important problem of the HMET epitaxy is that defects can occur during the epitaxial growth process, especially at the contact interface of the material, many lattice adaptation problems can occur, and the single-layer thick material can have cracks and dislocations during the thickness growth process, especially under the condition of high Al composition.

Therefore, it is an urgent technical problem to be solved by those skilled in the art to provide a HEMT epitaxial device based on a third generation semiconductor GaN material with low overall crystal quality and low additional resistance and a growth method thereof.

Disclosure of Invention

In view of the above, the present invention provides a HEMT epitaxial device based on a third generation semiconductor GaN material, which improves the overall crystal quality of the material and reduces the additional resistance caused by lattice adaptation of the material and the surface GaN contact through a first channel barrier layer AlGaN Al composition gradient growth technique.

In order to achieve the purpose, the invention adopts the following technical scheme:

a HEMT epitaxial device based on a third-generation semiconductor GaN material adopts the MOCVD technology to carry out heteroepitaxial growth on a substrate;

wherein, the HEMT epitaxial device includes: a substrate, a first GaN layer, a depletion high-resistance region and Al which are sequentially stacked from bottom to top_zGa_1-zThe GaN-based LED comprises an N layer, a 2DEG channel, an AlN layer, an AlGaN layer and a second GaN layer.

Further, the substrate is any one of sapphire, silicon, GaN, AlN, and SiC.

Further, the depletion high-resistance region sequentially comprises from bottom to top: GaN/Al_xGa_1-xN-SL layer, GaN/Al_yGa_1-yN-SL layer, GaN/Al_zGa_1-zN-SL layer and Al_aGa_1-aN/Al_zGa_1-zAn N-SL layer;

and the built-in electric field of the depletion high-resistance region from top to bottom is gradually reduced.

Further, the GaN/Al_xGa_1-x0 in N-SL layer<x is less than or equal to 0.1, and the GaN/Al_xGa_1-xThe thickness of the N-SL layer is 40-200 nm;

the GaN/Al_yGa_1-y0.1 in N-SL layer<y is less than or equal to 0.2, and the GaN/Al_yGa_1-yThe thickness of the N-SL layer is 40-200 nm;

the GaN/Al_zGa_1-z0.2 in N-SL layer<z is less than or equal to 0.3, and the GaN/Al_zGa_1-zThe thickness of the N-SL layer is 40-200 nm;

the Al is_aGa_1-aN/Al_zGa_1-z0.1 in N-SL layer<a≤0.2，0.2<z is less than or equal to 0.3, and Al_aGa_1-aN/Al_zGa_{1- z}The thickness of the N-SL layer is 40-200 nm.

Further, the 2DEG channel is a dual 2DEG channel or a multi 2DEG channel.

Further, the double 2DEG channel comprises, from bottom to top: a third GaN layer and an InAlN layer;

wherein the thickness of the third GaN layer is 100-300nm, and the thickness of the InAlN layer is 50-150 nm.

Further, the multiple 2DEG channels include, from bottom to top: an AlInGaN or InGaN layer, a third GaN layer and an InAlN layer;

the thickness of the AlInGaN or InGaN layer is 100-200nm, the thickness of the third GaN layer is 100-300nm, and the thickness of the InAlN layer is 50-150 nm.

Further, the Al_zGa_1-zThe N layer is a gradient layer of Al component; the Al is_zGa_1-z0.2 in the N layer<z is less than or equal to 0.3, and Al_zGa_1-zThe Al component in the N layer gradually changes from z to 0, and the Al_zGa_1-zThe thickness of the N layer is 10-30 nm;

the AlGaN layer is a gradient layer of Al component; the Al composition in the AlGaN layer is gradually changed from 0.25 to 0.35.

Furthermore, the thickness of the first GaN layer is 110-220 nm;

the AlN layer is 1-2nm thick; the thickness of the AlGaN layer is 20-50 nm; the thickness of the second GaN layer is 5-10 nm.

The invention also provides a growth method of the HEMT epitaxial device based on the third-generation semiconductor GaN material, which comprises the following steps:

(1) cleaning a substrate by dilute hydrochloric acid and isopropanol, washing by using water, then spin-drying, and baking in MOCVD equipment;

(2) introducing trimethyl gallium and ammonia gas to grow a first GaN layer on the substrate;

(3) introducing trimethyl aluminum, trimethyl gallium and ammonia gas to grow GaN/Al_xGa_1-xAn N-SL layer;

(4) introducing trimethyl aluminum, trimethyl gallium and ammonia gas to grow GaN/Al_yGa_1-yAn N-SL layer;

(5) introducing trimethyl aluminum, trimethyl gallium and ammonia gas to grow GaN/Al_zGa_1-zAn N-SL layer;

(6) introducing trimethyl aluminum, trimethyl gallium and ammonia gas to grow Al_aGa_1-aN/Al_zGa_1-zAn N-SL layer;

(7) introducing trimethylaluminum, trimethylgallium and ammonia gas, gradually decreasing the growth flow of the trimethylaluminum to 0sccm, keeping the source flow of the trimethylgallium unchanged, and growing Al with gradually changed Al components_zGa_1-zN layers;

(8) introducing trimethyl gallium and ammonia gas to grow a third GaN layer;

(9) introducing trimethyl aluminum, trimethyl indium and ammonia gas to grow an InAlN layer with the aluminum component of 0.82 and the indium component of 0.18;

(10) introducing trimethylaluminum and ammonia gas to grow an AlN layer;

(11) introducing trimethyl aluminum, trimethyl gallium and ammonia gas, setting the growth flow of trimethyl gallium to be constant, setting the source flow of trimethyl aluminum to gradually decrease to 0sccm from the growth of the layer to the end, and growing an AlGaN layer with gradually changed aluminum components;

(12) and introducing trimethyl gallium and ammonia gas to grow a second GaN layer to obtain the HEMT epitaxial device.

Further, in the step (1), the baking temperature is 1200 ℃, and the baking time is 10 min.

Further, the specific growth method of the first GaN layer in the step (2) is as follows:

cooling the equipment to 500 ℃, introducing trimethyl gallium and ammonia gas to grow a layer of GaN with the thickness of 10-20nm at the air pressure of 150torr, then heating to 1020 ℃, and growing 100-inch ion-doped 200nmGaN at the air pressure of 250 torr;

further, the GaN/Al in the step (3)_xGa_1-xThe specific growth method of the N-SL layer comprises the following steps:

introducing trimethylaluminum, trimethylgallium and ammonia gas at 1040 ℃ and 300torr to grow a layer of 1-2nm Al_xGa_1-xN; then, a layer of GaN with the thickness of 1-2nm grows at the temperature of 1030 ℃ and the air pressure of 280 torr; then repeating the above operation cycle for 20-50 cycles;

further, the GaN/Al in the step (4)_yGa_1-yThe specific growth method of the N-SL layer comprises the following steps:

introducing trimethylaluminum, trimethylgallium and ammonia gas at 1050 ℃ and 300torr of air pressure to grow a layer of 1-2nm Al_yGa_1-yN; then, a layer of GaN with the thickness of 1-2nm grows at 1040 ℃ and the air pressure of 280 torr; then repeating the above operation cycle for 20-50 cycles;

further, the GaN/Al in the step (5)_zGa_1-zThe specific growth method of the N-SL layer comprises the following steps:

introducing trimethylaluminum, trimethylgallium and ammonia gas at 1060 ℃ and 330torr in pressure to grow a layer of 1-2nm Al_zGa_1-zN; then, a layer of GaN with the thickness of 1-2nm grows at 1040 ℃ and the air pressure of 280 torr; and then repeating the cycle of the operation for 20-50 cycles.

Further, Al in the step (6)_aGa_1-aN/Al_zGa_1-zThe specific growth method of the N-SL layer comprises the following steps:

introducing trimethylaluminum, trimethylgallium and ammonia gas at 1060 ℃ and 330torr in pressure to grow a layer of 1-2nm Al_aGa_1-aN; under the same condition, a layer of 1-2nm Al is grown continuously_zGa_1-zN; and then repeating the cycle of the operation for 20-50 cycles.

Further, Al described in the step (7)_zGa_1-zThe specific growth method of the N layer comprises the following steps:

introducing trimethylaluminum, trimethylgallium and ammonia gas at 1060 ℃ and 330torr of air pressure, gradually decreasing the growth flow of the trimethylaluminum to 0sccm, keeping the source flow of the trimethylgallium unchanged, and growing an AlGaN → GaN composition gradient layer with the Al composition gradually reduced to 0;

further, the specific growth method of the third GaN layer in step (8) is:

introducing trimethyl gallium and ammonia gas to grow a third GaN layer at the temperature of 1030 ℃ and the air pressure of 250 torr;

further, the specific growth method of the InAlN layer in step (9) is as follows:

introducing trimethyl aluminum, trimethyl indium and ammonia gas at the temperature of 900 ℃ and the pressure of 300torr to grow a layer of InAlN, wherein the aluminum component is 0.82, and the indium component is 0.18.

Further, the specific growth method of the AlN layer in step (10) is:

introducing trimethylaluminum and ammonia gas at 1070 ℃ and the pressure of 350torr to grow an AlN layer;

further, the specific growth method of the AlGaN layer in the step (11) is as follows:

introducing trimethylaluminum, trimethylgallium and ammonia gas at 1050 ℃ and the pressure of 300torr to grow an AlGaN layer with aluminum components gradually changed into 0, wherein the initial aluminum component content is 0.25-0.35, the growth flow of the trimethylgallium is constant, and the source flow of the trimethylaluminum is gradually reduced to 0sccm from the growth of the AlGaN layer to the completion of the growth of the AlGaN layer;

further, the specific growth method of the second GaN layer in step (12) is:

and introducing trimethyl gallium and ammonia gas to grow a second GaN layer at the temperature of 1030 ℃ and the air pressure of 250 torr.

The invention has the beneficial effects that: according to the invention, three kinds of AlGaN/InAlN/GaN forbidden band width decreasing materials or four or more kinds of forbidden band width decreasing materials are adopted, and the forbidden band width decreasing material combination can generate a double-channel 2DEG or a multi-channel 2 DEG; because the conduction band energy level of the heterojunction material is continuously reduced, two or more generated 2DEG are all arranged on the low-forbidden-band-width material on the same side, the directions of built-in electric fields are consistent, when reverse bias voltage is applied to a grid, the grid can be rapidly clamped off, the control of the grid voltage is facilitated, the I-V characteristic is improved, the influence of leakage current is eliminated, the high current gain and cut-off frequency are improved, and the high-frequency performance and the output power of the device are enhanced.

The invention adopts GaN/Al_xGa_1-xThe superlattice structure with gradually-changed components such as N-SL and the like can reduce the stress of material growth, and meanwhile, as the forbidden bandwidth of the material is gradually increased upwards by the substrate, background electrons move to a low-energy region to form a built-in electric field pointing to the substrate, so that a depletion layer in a local region is generated, the concentration of free electrons is greatly reduced, a relatively high-resistance region is formed, and a current collapse and leakage channel is reduced.

According to the invention, through the Al component gradient growth technology of the AlGaN of the first channel barrier layer, the total crystal quality of the material is improved, and the additional resistance caused by the matching of the contact crystal lattice of the material and the surface GaN is reduced.

Drawings

FIG. 1 is a diagram of a multi-2 DEG channel HEMT epitaxy structure provided by the present invention;

FIG. 2 is a schematic view of the position of a 2DEG in an epitaxial layer of a dual 2DEG channel HEMT provided by the present invention;

FIG. 3 is a schematic view of the 2DEG position in the epitaxial layer of the multi-2 DEG channel HEMT provided by the present invention;

fig. 4 is a schematic diagram of a depletion high-resistance region.

In the drawings, the structures represented by the reference numerals are listed below: 1-substrate, 2-first GaN layer, 3-depletion high resistance region, 4-Al_zGa_1-zThe LED comprises an N layer, a 5-2DEG channel, a 6-AlN layer, a 7-AlGaN layer and an 8-second GaN layer;

31-GaN/Al_xGa_1-xN-SL layer, 32-GaN/Al_yGa_1-yN-SL layer, 33-GaN/Al_zGa_1-zN-SL layer, 34-Al_aGa_1-aN/Al_zGa_1-zAn N-SL layer, a 51-AlInGaN or InGaN layer, a 52-third GaN layer, a 53-InAlN layer.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1

A HEMT epitaxial device based on the third generation semiconductor GaN material applies the Metal Organic Chemical Vapor Deposition (MOCVD) epitaxial growth technology and adopts trimethyl gallium (TMGa), trimethyl indium (TMIn), trimethyl aluminum (TMAl) and ammonia (NH)₃) Silane (SiH)₄) Respectively providing a gallium source, an indium source, an aluminum source, a nitrogen source and a silicon source which are required by growth, and taking nitrogen and hydrogen as carrier gases;

(1) cleaning the substrate with dilute hydrochloric acid and isopropanol, washing with water, spin-drying, and baking in MOCVD equipment at 1200 deg.C for 10 min;

(2) cooling the equipment to 500 ℃, introducing trimethyl gallium and ammonia gas to grow a layer of GaN with the thickness of 10nm under the pressure of 150torr, and then heating to 1020 ℃, and growing 100nmGaN under the pressure of 250 torr;

(3) introducing trimethylaluminum, trimethylgallium and ammonia gas at 1040 ℃ and 300torr to grow a layer of 1nm Al_0.01Ga_0.99N; then, a layer of GaN with the thickness of 1nm grows at the temperature of 1030 ℃ and the air pressure of 280 torr; then repeating the above operation cycle to grow for 20 cycles;

(4) introducing trimethylaluminum, trimethylgallium and ammonia gas at 1050 ℃ and 300torr of air pressure to grow a layer of 1nm Al_0.11Ga_0.89N; then, a layer of GaN with the thickness of 1nm grows at 1040 ℃ and the air pressure of 280 torr; then repeating the above operation cycle to grow for 20 cycles;

(5) introducing trimethylaluminum, trimethylgallium and ammonia gas at 1060 ℃ and 330torr in pressure to grow a layer of 1nm Al_0.21Ga_0.79N; then, a layer of GaN with the thickness of 1nm grows at 1040 ℃ and the air pressure of 280 torr; then repeating the above operation cycle to grow for 20 cycles;

(6) introducing trimethylaluminum, trimethylgallium and ammonia gas at 1060 ℃ and 330torr in pressure to grow a layer of 1nm Al_0.11Ga_0.89N; under the same condition, a layer of 1nm Al is grown continuously_0.21Ga_0.79N; then repeating the above operation cycle to grow for 20 cycles;

(7) introducing trimethylaluminum, trimethylgallium and ammonia gas at 1060 ℃ and 330torr of air pressure, gradually decreasing the growth flow of the trimethylaluminum to 0sccm, keeping the source flow of the trimethylgallium unchanged, and growing a 10nm AlGaN → GaN composition gradient layer with the Al composition gradually reduced to 0;

(8) introducing trimethyl gallium and ammonia gas to grow a third GaN layer with the thickness of 100nm at the temperature of 1030 ℃ and the air pressure of 250 torr;

(9) introducing trimethyl aluminum, trimethyl indium and ammonia gas at the temperature of 900 ℃ and the pressure of 300torr to grow a 50nm thick InAlN layer, wherein the aluminum component is 0.82, and the indium component is 0.18;

(10) introducing trimethylaluminum and ammonia gas at 1070 ℃ and the pressure of 350torr to grow an AlN layer with the thickness of 1 nm;

(11) introducing trimethylaluminum, trimethylgallium and ammonia gas at 1050 ℃ and the pressure of 300torr, growing an AlGaN layer with the thickness of 20nm, wherein the aluminum component gradually changes into 0, the initial aluminum component content is 0.25, the growth flow of the trimethylgallium is constant, and the source flow of the trimethylaluminum is gradually reduced to 0sccm from the growth of the AlGaN layer to the end;

(12) and introducing trimethyl gallium and ammonia gas to grow a second GaN layer with the thickness of 5nm at the temperature of 1030 ℃ and the pressure of 250torr to obtain the HEMT epitaxial device.

Example 2

A HEMT epitaxial device based on the third generation semiconductor GaN material applies the Metal Organic Chemical Vapor Deposition (MOCVD) epitaxial growth technology and adopts trimethyl gallium (TMGa), trimethyl indium (TMIn), trimethyl aluminum (TMAl) and ammonia (NH)₃) Silane (SiH)₄) Respectively providing a gallium source, an indium source, an aluminum source, a nitrogen source and a silicon source which are required by growth, and taking nitrogen and hydrogen as carrier gases;

(1) cleaning the substrate with dilute hydrochloric acid and isopropanol, washing with water, spin-drying, and baking in MOCVD equipment at 1200 deg.C for 10 min;

(2) cooling the equipment to 500 ℃, introducing trimethyl gallium and ammonia gas to grow a layer of 20nm GaN at the air pressure of 150torr, and then heating to 1020 ℃, growing 200nm GaN at the air pressure of 250 torr;

(3) introducing trimethylaluminum, trimethylgallium and ammonia gas at 1040 ℃ and 300torr to grow a layer of 2nm Al_0.1Ga_0.9N; then, a layer of GaN with the thickness of 2nm grows at the temperature of 1030 ℃ and the air pressure of 280 torr; then repeating the above operation cycle for 50 cycles;

(4) introducing trimethylaluminum, trimethylgallium and ammonia gas at 1050 ℃ and 300torr of air pressure to grow a layer of 2nm Al_0.2Ga_0.8N; then, a layer of 2nm GaN grows at 1040 ℃ and 280torr of air pressure; then repeating the above operation cycle for 50 cycles;

(5) introducing trimethylaluminum, trimethylgallium and ammonia gas at 1060 ℃ and 330torr in pressure to grow a 2nm layer of Al_0.3Ga_0.7N; then, a layer of 2nm GaN grows at 1040 ℃ and 280torr of air pressure; then repeating the above operation cycle for 50 cycles;

(6) introducing trimethylaluminum, trimethylgallium and ammonia gas at 1060 ℃ and 330torr in pressure to grow a 2nm layer of Al_0.2Ga_0.8N; under the same condition, a layer of 2nm Al is grown_0.3Ga_0.7N; then repeating the above operation cycle for 50 cycles;

(7) introducing trimethylaluminum, trimethylgallium and ammonia gas at 1060 ℃ and 330torr of air pressure, gradually decreasing the growth flow of the trimethylaluminum to 0sccm, keeping the source flow of the trimethylgallium unchanged, and growing a 30nm AlGaN → GaN composition gradient layer with Al components gradually reduced to 0;

(8) introducing trimethyl gallium and ammonia gas to grow a third GaN layer with the thickness of 300nm at the temperature of 1030 ℃ and the air pressure of 250 torr;

(9) introducing trimethyl aluminum, trimethyl indium and ammonia gas at the temperature of 900 ℃ and the pressure of 300torr to grow a 150nm thick InAlN layer, wherein the aluminum component is 0.82, and the indium component is 0.18;

(10) introducing trimethylaluminum and ammonia gas at 1070 ℃ and the pressure of 350torr to grow an AlN layer with the thickness of 2 nm;

(11) introducing trimethylaluminum, trimethylgallium and ammonia gas at 1050 ℃ and the pressure of 300torr, growing an AlGaN layer with the thickness of 50nm, wherein the aluminum component gradually changes into 0, the initial aluminum component content is 0.35, the growth flow of the trimethylgallium is constant, and the source flow of the trimethylaluminum is gradually reduced to 0sccm from the growth of the AlGaN layer to the end;

(12) and introducing trimethyl gallium and ammonia gas to grow a second GaN layer with the thickness of 10nm at the temperature of 1030 ℃ and the pressure of 250torr to obtain the HEMT epitaxial device.

Example 3

A HEMT epitaxial device based on the third generation semiconductor GaN material applies the Metal Organic Chemical Vapor Deposition (MOCVD) epitaxial growth technology and adopts trimethyl gallium (TMGa), trimethyl indium (TMIn), trimethyl aluminum (TMAl) and ammonia (NH)₃) Silane (SiH)₄) Respectively providing a gallium source, an indium source, an aluminum source, a nitrogen source and a silicon source which are required by growth, and taking nitrogen and hydrogen as carrier gases;

(1) cleaning the substrate with dilute hydrochloric acid and isopropanol, washing with water, spin-drying, and baking in MOCVD equipment at 1200 deg.C for 10 min;

(2) cooling the equipment to 500 ℃, introducing trimethyl gallium and ammonia gas to grow a layer of GaN with the thickness of 12nm under the pressure of 150torr, and then heating to 1020 ℃, and growing 150nm GaN under the pressure of 250 torr;

(3) introducing trimethylaluminum, trimethylgallium and ammonia gas at 1040 ℃ and 300torr to grow a layer of 2nm Al_0.05Ga_0.95N; then, a layer of GaN with the thickness of 2nm grows at the temperature of 1030 ℃ and the air pressure of 280 torr; then repeating the above operation cycle to grow for 30 cycles;

(4) introducing trimethylaluminum, trimethylgallium and ammonia gas at 1050 ℃ and 300torr of air pressure to grow a layer of 2nm Al_0.15Ga_0.85N; then, a layer of GaN with the thickness of 1nm grows at 1040 ℃ and the air pressure of 280 torr; then repeating the above operation cycle for 35 cycles;

(5) introducing trimethylaluminum, trimethylgallium and ammonia gas at 1060 ℃ and 330torr in pressure to grow a 2nm layer of Al_0.25Ga_0.75N; then, a layer of 2nm GaN grows at 1040 ℃ and 280torr of air pressure; then repeating the above operation cycle to grow 40 cycles;

(6) introducing trimethylaluminum, trimethylgallium and ammonia gas at 1060 ℃ and 330torr in pressure to grow a 2nm layer of Al_0.15Ga_0.85N; under the same condition, a layer of 1nm Al is grown continuously_0.25Ga_0.75N；Then repeating the above operation cycle for 25 cycles;

(7) introducing trimethylaluminum, trimethylgallium and ammonia gas at 1060 ℃ and 330torr of air pressure, gradually decreasing the growth flow of the trimethylaluminum to 0sccm, keeping the source flow of the trimethylgallium unchanged, and growing a 20nm AlGaN → GaN component gradient layer with the Al component gradually reduced to 0;

(8) introducing trimethyl gallium and ammonia gas to grow a third GaN layer with the thickness of 200nm at the temperature of 1030 ℃ and the air pressure of 250 torr;

(9) introducing trimethyl aluminum, trimethyl indium and ammonia gas at the temperature of 900 ℃ and the pressure of 300torr to grow a 100nm thick InAlN layer, wherein the aluminum component is 0.82, and the indium component is 0.18;

(10) introducing trimethylaluminum and ammonia gas at 1070 ℃ and the pressure of 350torr to grow an AlN layer with the thickness of 2 nm;

(11) introducing trimethylaluminum, trimethylgallium and ammonia gas at 1050 ℃ and the pressure of 300torr, growing an AlGaN layer with the thickness of 30nm, wherein the aluminum component gradually changes into 0, the initial aluminum component content is 0.3, the growth flow of the trimethylgallium is constant, and the source flow of the trimethylaluminum is gradually reduced to 0sccm from the growth of the AlGaN layer to the end;

(12) and introducing trimethyl gallium and ammonia gas to grow a 7nm thick second GaN layer at the temperature of 1030 ℃ and the air pressure of 250torr to obtain the HEMT epitaxial device.

Example 4

A HEMT epitaxial device based on the third generation semiconductor GaN material applies the Metal Organic Chemical Vapor Deposition (MOCVD) epitaxial growth technology and adopts trimethyl gallium (TMGa), trimethyl indium (TMIn), trimethyl aluminum (TMAl) and ammonia (NH)₃) Silane (SiH)₄) Respectively providing a gallium source, an indium source, an aluminum source, a nitrogen source and a silicon source which are required by growth, and taking nitrogen and hydrogen as carrier gases;

(1) cleaning the substrate with dilute hydrochloric acid and isopropanol, washing with water, spin-drying, and baking in MOCVD equipment at 1200 deg.C for 10 min;

(2) cooling the equipment to 500 ℃, introducing trimethyl gallium and ammonia gas to grow a layer of 15nm GaN at the air pressure of 150torr, and then heating to 1020 ℃, growing 120nm GaN at the air pressure of 250 torr;

(3) introducing trimethylaluminum, trimethylgallium and ammonia gas at 1040 ℃ and 300torr to grow a layer of 1nm Al_0.06Ga_0.94N; then, a layer of GaN with the thickness of 1nm grows at the temperature of 1030 ℃ and the air pressure of 280 torr; then repeating the above operation cycle period to grow for 45 periods;

(4) introducing trimethylaluminum, trimethylgallium and ammonia gas at 1050 ℃ and 300torr of air pressure to grow a layer of 1nm Al_0.12Ga_0.88N; then, a layer of 2nm GaN grows at 1040 ℃ and 280torr of air pressure; then repeating the above operation cycle to grow for 36 cycles;

(5) introducing trimethylaluminum, trimethylgallium and ammonia gas at 1060 ℃ and 330torr in pressure to grow a 2nm layer of Al_0.23Ga_0.77N; then, a layer of GaN with the thickness of 1nm grows at 1040 ℃ and the air pressure of 280 torr; then repeating the above operation cycle to grow 27 cycles;

(6) introducing trimethylaluminum, trimethylgallium and ammonia gas at 1060 ℃ and 330torr in pressure to grow a 2nm layer of Al_0.16Ga_0.84N; under the same condition, a layer of 2nm Al is grown_0.23Ga_0.77N; then repeating the above operation cycle to grow for 42 cycles;

(7) introducing trimethylaluminum, trimethylgallium and ammonia gas at 1060 ℃ and 330torr of air pressure, gradually decreasing the growth flow of the trimethylaluminum to 0sccm, keeping the source flow of the trimethylgallium unchanged, and growing a 25nm AlGaN → GaN component gradient layer with the Al component gradually reduced to 0;

(8) introducing trimethyl gallium and ammonia gas to grow a third GaN layer with the thickness of 220nm at the temperature of 1030 ℃ and the air pressure of 250 torr;

(9) introducing trimethyl aluminum, trimethyl indium and ammonia gas at the temperature of 900 ℃ and the pressure of 300torr to grow an InAlN layer with the thickness of 80nm, wherein the aluminum component is 0.82, and the indium component is 0.18;

(10) introducing trimethylaluminum and ammonia gas at 1070 ℃ and the pressure of 350torr to grow an AlN layer with the thickness of 1 nm;

(11) introducing trimethylaluminum, trimethylgallium and ammonia gas at 1050 ℃ and the pressure of 300torr, growing an AlGaN layer with the thickness of 20-50nm, wherein the aluminum component gradually changes into 0, the initial aluminum component content is 0.28, the growth flow of the trimethylgallium is constant, and the source flow of the trimethylaluminum is gradually reduced to 0sccm from the growth of the AlGaN layer to the end;

(12) and introducing trimethyl gallium and ammonia gas to grow a second GaN layer with the thickness of 8nm at the temperature of 1030 ℃ and the pressure of 250torr to obtain the HEMT epitaxial device.

Example 5

A HEMT epitaxial device based on the third generation semiconductor GaN material applies the Metal Organic Chemical Vapor Deposition (MOCVD) epitaxial growth technology and adopts trimethyl gallium (TMGa), trimethyl indium (TMIn), trimethyl aluminum (TMAl) and ammonia (NH)₃) Silane (SiH)₄) Respectively providing a gallium source, an indium source, an aluminum source, a nitrogen source and a silicon source which are required by growth, and taking nitrogen and hydrogen as carrier gases;

(1) cleaning the substrate with dilute hydrochloric acid and isopropanol, washing with water, spin-drying, and baking in MOCVD equipment at 1200 deg.C for 10 min;

(2) cooling the equipment to 500 ℃, introducing trimethyl gallium and ammonia gas to grow a layer of 18nm GaN at the air pressure of 150torr, and then heating to 1020 ℃, growing 165nmGaN at the air pressure of 250 torr;

(3) introducing trimethylaluminum, trimethylgallium and ammonia gas at 1040 ℃ and 300torr to grow a layer of 2nm Al_0.08Ga_0.92N; then, a layer of GaN with the thickness of 2nm grows at the temperature of 1030 ℃ and the air pressure of 280 torr; then repeating the above operation cycle to grow for 36 cycles;

(4) introducing trimethylaluminum, trimethylgallium and ammonia gas at 1050 ℃ and 300torr of air pressure to grow a layer of 2nm Al_0.17Ga_0.83N; then, a layer of 2nm GaN grows at 1040 ℃ and 280torr of air pressure; then repeating the above operation cycle period to grow 43 periods;

(5) introducing trimethylaluminum, trimethylgallium and ammonia gas at 1060 ℃ and 330torr in pressure to grow a 2nm layer of Al_0.24Ga_0.76N; then, a layer of 2nm GaN grows at 1040 ℃ and 280torr of air pressure; then repeating the above operation cycle to grow 28 cycles;

(6) introducing trimethyl aluminum at 1060 ℃ and 330torr of air pressure,Trimethyl gallium and ammonia gas, growing a layer of 2nm Al_0.13Ga_0.87N; under the same condition, a layer of 1nm Al is grown continuously_0.24Ga_0.76N; then repeating the above operation cycle for 50 cycles;

(7) introducing trimethylaluminum, trimethylgallium and ammonia gas at 1060 ℃ and 330torr of air pressure, gradually decreasing the growth flow of the trimethylaluminum to 0sccm, keeping the source flow of the trimethylgallium unchanged, and growing a 24nm AlGaN → GaN component gradient layer with the Al component gradually reduced to 0;

(8) introducing trimethyl gallium and ammonia gas to grow a third GaN layer with the thickness of 260nm at the temperature of 1030 ℃ and the air pressure of 250 torr;

(9) introducing trimethyl aluminum, trimethyl indium and ammonia gas at the temperature of 900 ℃ and the pressure of 300torr to grow an InAlN layer with the thickness of 110nm, wherein the aluminum component is 0.82, and the indium component is 0.18;

(10) introducing trimethylaluminum and ammonia gas at 1070 ℃ and the pressure of 350torr to grow an AlN layer with the thickness of 2 nm;

(11) introducing trimethylaluminum, trimethylgallium and ammonia gas at 1050 ℃ and the pressure of 300torr, growing an AlGaN layer with the thickness of 45nm, wherein the aluminum component gradually changes into 0, the initial aluminum component content is 0.32, the growth flow of the trimethylgallium is constant, and the source flow of the trimethylaluminum is gradually reduced to 0sccm from the growth of the AlGaN layer to the end;

(12) and introducing trimethyl gallium and ammonia gas to grow a second GaN layer with the thickness of 10nm at the temperature of 1030 ℃ and the pressure of 250torr to obtain the HEMT epitaxial device.

Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.