CN105374677B - A kind of method that high electron mobility field-effect transistor is prepared on large scale Si substrates - Google Patents

Abstract

The present invention provides a kind of method that high electron mobility field-effect transistor (HEMT) is prepared on large scale Si substrates more particularly to a kind of use carbon nanotubes as periodic dielectric mask, using selective area epitaxial（SAG）Method prepares no cracking, the AlGaN/GaN HEMT device methods of high-crystal quality.Metal organic chemical vapor deposition technology growth AlN nucleating layers and AlGaN seed layers are used on a si substrate；Then Low Pressure Chemical Vapor Deposition is used（LPCVD）, the multilayer carbon nanotube of marshalling is grown, by growing and weaving, ultimately forms continuous carbon nano-tube film；Selective area epitaxial is used on this basis（SAG）Method using GaN in the selectivity of medium mask and Grown, GaN epitaxial layer is limited in the region of no medium mask and grown, form discrete window, so as to discharge the tensile stress in entire epitaxial layer；Using the Al of multicycle Al content gradually variational_y1Ga_1‑y1N/GaN superlattices or AlN/Al_y1Ga_1‑y1N/GaN superlattices obtain no cracking, the GaN epitaxial layer of high-crystal quality as stress regulation and control layer.AlGaN/GaN HEMT devices are prepared on this basis.

Description

It is a kind of to prepare high electron mobility field-effect transistor on large scale Si substrates Method

Technical field

Prepared the present invention relates to one kind on large scale Si substrates high electron mobility [field-effect] transistor (HEMT, High electron mobility transistor) method.More particularly to a kind of be used as using carbon nanotubes is periodically situated between Matter mask is grown using constituency [extension],（selective area growth,SAG）Method prepares no cracking, high crystal matter The AlGaN/GaN HEMT device methods of amount, belong to field of semiconductor photoelectron technique.

Background technology

High electron mobility field-effect transistor（HEMT）, it is also known as modulation-doped FET（MODFET, modulation-doped field effect transistor）, it is a kind of with substrate material and another broadband material shape Into heterogeneous interface two-dimensional electron gas conduction field-effect transistor（FET）.Because of free from admixture in its raceway groove, it is substantially absent from Influence of the ionized impurity scattering to electron motion, thus electron mobility higher and gain the name.The operation principle of HEMT is to pass through control The variation of grid voltage processed makes the channel current between source electrode, drain electrode generate corresponding variation, so as to reach the mesh of amplified signal 's.Its advantage is that have high frequency and low noise characteristic.HEMT has been used for satellite television, mobile communication, military communication In the receiving circuit of radar system.Since GaAs based hemts in 1980 are succeeded in developing, development quickly has been obtained.GaAs Based hemts have been widely used in radio frequency, microwave and millimeter wave low-frequency range.InP devices have higher work than GaAs HEMT Working frequency and lower noise, for millimeter wave high band and submillimeter wave frequency range.The characteristics of GaN HEMT devices be high temperature resistant, It is high-power, there is huge application prospect, particularly occupy superiority in 10-40GHz.

AlGaN/GaN HEMT are big due to the GaN band gap widths as channel layer（3.4eV）, breakdown voltage height (3.3MV/ Cm), saturated electrons speed is big（2.8*10⁷s^-1）It is high with two-dimensional electron gas surface density（10¹³cm²）Etc. characteristics, cause GaN base HEMT Research develop to higher working frequency, bigger output power, more elevated operating temperature and practical direction.GaN base HEMT may be used also In terms of high speed switch integrated circuit and high pressure DC-DC converter.AlGaN/GaN HEMT are grown in semi-insulated （0001）Si faces SiC or（0001）In Sapphire Substrate, one layer of semi-insulated GaN is grown after coring layer（About 2 μm）Channel layer, Then the AlGaN separation layers to undope are grown, mix the AlGaN of Si and the AlGaN barrier layers to undope.Two-dimensional electron gas shape Into in channel layer/isolation bed boundary.Si substrate dimensions are big, inexpensive can reduce epitaxial growth cost.Comparison hardness is big, heat conduction The adiabatic Sapphire Substrate of difference simplifies the processing technologys such as substrate thinning, reduces device making technics cost.

The gas phase epitaxy of metal organic compound on Si（Metalorganic vapor phase epitaxy, MOVPE）Growth The difficult point of GaN is：GaN Wurzite structures（0001）With the Si of diamond lattic structure（111）The lattice mismatch of substrate is 20.4%, substantial amounts of dislocation can be generated；Thermal mismatching between GaN and Si is up to 56%, in the cooling engineering after epitaxial growth, Epitaxial layer will bear very big tensile stress.Since epitaxy layer thickness is much smaller than substrate thickness, so can generate in the epitaxial layer micro- Crackle seriously affects GaN device characteristic.On Si substrates during direct growth GaN, NH₃It easily reacts and is serving as a contrast with substrate Si Bottom surface forms amorphous SiN, influences the growth quality of GaN.Also there is very strong chemical reaction between metal Ga and substrate Si, Back dissolving can be caused to substrate, so as to destroy the smooth of interface.In high growth temperature, the Si in substrate can diffuse to buffer layer table Face, if control is improper, it will the growth pattern of GaN is influenced, so as to destroy crystal quality.Additionally due to Si is nonpolar partly to lead It is related will to lead to the problem of some compound polarity when growing GaN, AlN or other polar semiconductors on it for body.

It is the effective of lattice mismatch when solving Si substrate growth GaN, Si diffusions and polarity problems using suitable buffer layer Means, while the stress in film can also be alleviated to a certain extent.People attempted many methods therefore, as AlAs, The compound buffer layers such as AlN and AlGaN/AlN.Wherein AlN results are best, and major advantage is both can be with GaN same anti- Room is answered to be grown, and can be to avoid the formation of SiN during high growth temperature.Many solution party are proposed according to its stress release mechanism Method：

(1) buffer layer stress compensation method：A compression is provided by buffer layer to upper strata GaN to cause to compensate thermal mismatching Tensile stress.Such as using the Al of 5 gradients_xGa_1-xN (x=0.87,0.67,0.47,0.27 and 0.07) buffer layer, the results showed that Cracking density significantly reduces, and optical characteristics also improves a lot.

(2) it is inserted into ply stress cutting-out method：It adjusts the stress state inside film by insert layer or stops since heat is lost Propagation with the tensile stress being passed to from substrate.Such as superlattices insert layer method：The AlN/GaN superlattices in 10 cycles of insertion are inserted into Layer, growth GaN overall thickness are 2 μm, and with the increase of the superlattices insert layer number of plies, tensile strain is reduced.TEM show dislocation density with Thickness change and reduce.

However use the insertion layer method of current mainstream that can not completely eliminate stress, and existing defects density is big, warpage The problems such as.Moreover reduce GaN dislocation densities effectively routine ELOG（epitaxial lateral overgrowth, ELOG） Technology is difficult to apply on AlGaN, because Al atoms are poor in the transfer ability of growing surface, AlGaN can sink on mask Product.

The present invention, on large scale Si substrates, using carbon nanotubes as periodic dielectric mask, using selective area epitaxial （SAG）Method prepares no cracking, the AlGaN/GaN HEMT devices of high-crystal quality, can not only efficiently solve technology so far In there are still undesirable stress and defect, effectively alleviate warpage.

The content of the invention

The present invention provides the side that one kind prepares high electron mobility field-effect transistor (HEMT) on large scale Si substrates Method, technical scheme is as follows：On a si substrate,（1）Using metal organic chemical vapor deposition technology growth AlN into Stratum nucleare and AlGaN seed layers.(2) and then using Low Pressure Chemical Vapor Deposition（LPCVD, Low Pressure Chemical Vapor Deposition）, using acetylene as carrier gas, while the Fe of 5nm is used to grow the more of marshalling as catalyst Layer carbon nanotubes.Carbon nanotube diameter after growth is 15nm.By growing and weaving, finally by carbon nanotubes arranged in parallel Array can form continuous carbon nano-tube film.（3）Selective area epitaxial is used on this basis（SAG）Method is being situated between using GaN The selectivity of matter mask and Grown is limited in GaN epitaxial layer in the region of no hidden film and grows, formed discrete Window utilizes " controlled facet growth technique " to bend dislocation, so as to drop low threading dislocation density on entire area, discharges Tensile stress in entire epitaxial layer, obtains no cracking, the GaN epitaxial layer of high-crystal quality.（4）The multicycle is grown on this basis The Al of Al content gradually variationals_y1Ga_1-y1N/GaN superlattices or AlN/Al_y1Ga_1-y1N/GaN superlattices are as stress regulation and control layer.（5）Most AlGaN/GaN HEMT devices are prepared eventually.This method comprises the following steps：

Step 1, in Metal Organic Vapor epitaxial reactor, in hydrogen（H₂）Under atmosphere, on a si substrate, At 1000 DEG C~1500 DEG C of temperature, TMAl is passed through as group III source, NH₃As group V source, 0.1~0.5 micron of thickness AlN of growth into Stratum nucleare；On this basis, at 1000 DEG C~1500 DEG C of temperature, TMAl, TMGa are passed through as group III source, NH₃It is raw as group V source Long 0.1~1 micron of thickness AlGaN seed layer.

Step 2, using Low Pressure Chemical Vapor Deposition（LPCVD）Grow the multilayer carbon nanotube of marshalling.It is growing In the process, using acetylene as carrier gas, while using Fe as catalyst.Carbon nanotube diameter after growth is 15nm.Pass through Growth and braiding, finally form continuous carbon nano-tube film by carbon nano pipe array arranged in parallel.

Step 3, in hydrogen（H₂）Under atmosphere, at 1000 DEG C~1500 DEG C, TMGa is passed through as group III source, NH₃As Group V source, on this basis using selective area epitaxial（SAG）Method, using GaN medium mask and Grown selectivity, GaN epitaxial layer is limited in the region of no medium mask and is grown, forms discrete window, discharges in entire epitaxial layer Stress grows 0.1~1 micron of GaN and merges layer.

Step 4, in hydrogen（H₂）Under atmosphere, at 1000 DEG C~1500 DEG C, TMGa, TMAl are passed through as group III source, NH₃The Al of Al composition gradient gradual changes as group V source growth multicycle unsymmetric structure_y1Ga_1-y1N/GaN superlattices or AlN/ Al_y1Ga_1-y1N/GaN superlattices, as stress regulation and control layer, number of superlattice cycles are 1~20.The wherein thickness of superlattices well layer GaN It spends for 1~5nm, superlattices Al_y1Ga_1-y1The thickness of N barrier layer is 1~5nm, and the thickness of superlattices AlN insert layers is 1~5nm；

Al components y₁As the increase of stress regulation and control layer number of superlattice cycles is reduced from 1 gradient to 0（0≤y1≤1).

Step 5, in hydrogen（H₂）Under atmosphere, at 1050 DEG C~1200 DEG C, TMGa is passed through as group III source, NH₃As Group V source grows 2~4 microns of thickness μ-GaN semi-insulating layers.Then TMGa, TMAl are passed through as group III source, NH₃As group V source, SiH₄As 5nm~15nm AlGaN separation layers for undoping of n-shaped doped source growth, 10nm~20nm mixes the AlGaN and not of Si The AlGaN potential barrier of doping.

The method that one kind of the invention prepares high electron mobility field-effect transistor (HEMT) on large scale Si substrates, is adopted By the use of carbon nanotubes as periodic dielectric mask, using selective area epitaxial（SAG）Method prepares no cracking, high-crystal quality AlGaN/GaN HEMT devices can not only efficiently solve the even existing stress of technology and defect so far, effectively alleviate and stick up Song, and thermal conductivity can be effectively improved.

Description of the drawings

Fig. 1 be in the embodiment of the present invention 1 it is a kind of using carbon nanotubes as periodic dielectric mask and use Al_y1Ga_1-y1The sectional view of the new structure AlGaN/GaN HEMT devices of N/GaN superlattices stress regulation and control layers；

Fig. 2 be in the embodiment of the present invention 2 it is a kind of using carbon nanotubes as periodic dielectric mask and using AlN/ Al_y1Ga_1-y1The sectional view of N/GaN superlattices new structure AlGaN/GaN HEMT devices；

Fig. 3 (a）It is ordinary construction without being used using carbon nanotubes as periodic dielectric mask and not Al_y1Ga_1-y1N/GaN superlattices or AlN/Al_y1Ga_1-y1The AlGaN/GaN HEMT devices of N/GaN superlattices stress regulation and control layers SEM photograph：Fig. 3 (b),（c）It is the AlGaN/GaN HEMT devices using Example 1 and Example 2 of the present invention new structure SEM photograph.

Specific embodiment

The present invention provides the side that one kind prepares high electron mobility field-effect transistor (HEMT) on large scale Si substrates Method.Use trimethyl gallium（TMGa）, trimethyl aluminium（TMAl）As group III source, ammonia（NH₃）As group V source, silane（SiH₄） As n-shaped doped source, on a si substrate, first low-temperature epitaxy AlN nucleating layers and AlGaN seed layers.Creativeness is adopted on this basis By the use of carbon nanotubes as periodic dielectric mask, using selective area epitaxial（SAG）Method, and layer structure is regulated and controled by design stress, Obtain no cracking, the AlGaN epitaxial layers of high-crystal quality.And further prepare AlGaN/GaN HEMT devices.

Fig. 1 is the AlGaN/GaN HEMT device side, sectionals according to an embodiment of the invention for being used to implement the present invention Figure.Fig. 1 includes Si substrates 101, AlN nucleating layers and AlGaN seed layers 102, carbon nanotubes mask 103, and GaN merges layer 104；Al_y1Ga_1-y1N/GaN superlattices stress regulation and controls layer 105, u-GaN（undoped GaN）Semi-insulating layer 106.u-AlGaN (undoped AlGaN) separation layer 107, n-AlGaN (n-doped AlGaN) and u-AlGaN (undoped AlGaN) barrier layer 108。

Fig. 2 is the AlGaN/GaN HEMT device side, sectionals according to an embodiment of the invention for being used to implement the present invention Figure.Fig. 1 includes Si substrates 201, AlN nucleating layers and AlGaN seed layers 202, carbon nanotubes mask 203, and GaN merges layer 204；AlN/Al_y1Ga_1-y1N/GaN superlattices stress regulation and controls layer 205, u-GaN（undoped GaN）Semi-insulating layer 206.u- AlGaN (undoped AlGaN) separation layer 207, n-AlGaN (n-doped AlGaN) and u-AlGaN (undoped AlGaN) Barrier layer 208.

Wherein, the periodic dielectric mask on Si substrates uses carbon nanotubes, and stress regulation and control layer uses Al content gradually variationals AlGaN/AlGaN superlattices or AlN/AlGaN/GaN superlattice structures or other structures, as long as meet Al composition gradients gradually Become principle can.

Embodiment 1

Using Aixtron companies, the vertical reative cell MOCVD growing systems of close coupling.Trimethyl gallium is used in growth course （TMGa）, trimethyl aluminium（TMAl）As group III source, ammonia（NH₃）As group V source, silane（SiH₄）As n-shaped doped source, two Luxuriant magnesium（Cp₂Mg）As p-type doped source, Si substrates 101 are heated to 1080 DEG C in MOCVD reative cells first, in H₂Atmosphere Under, using TMGa, TMAl as group III source, NH₃As group V source, 0.1 micron of thickness AlN nucleating layer is grown；Then, 1080 ℃、H₂Under atmosphere, TMAl, TMGa are passed through as group III source, NH₃As group V source, 0.5 micron of thickness AlGaN seed layer 102 is grown. Using Low Pressure Chemical Vapor Deposition（LPCVD）Grow the multilayer carbon nanotube of marshalling.In growth course, using acetylene As carrier gas, while the Fe of 5nm is used as catalyst.Carbon nanotube diameter after growth is 15nm.By growing and weaving, Continuous carbon nano-tube film 103 finally can be formed by carbon nano pipe array arranged in parallel.In 1080 DEG C, H₂Under atmosphere, TMGa, TMAl are passed through as group III source, NH₃1 μm of GaN, which is grown, as group V source merges layer 104；In 1080 DEG C, H₂Under atmosphere, lead to Enter TMGa, TMAl as group III source, NH₃The Al composition gradient gradual changes of the unsymmetric structure in 20 cycles are grown as group V source （3nm）Al_y1Ga_1-y1N/ (3nm) GaN superlattices insert layers, as stress regulation and control layer 105.Wherein Al components y1 is with superlattices week It is by the way that the flow of TMAl is controlled to realize that issue increase, which is reduced from 1 staged to 0.05, Al component stepped changes,（With superlattices week Issue increases Al components y₁Be followed successively by 1,0.95,0.9,0.85,0.8,0.75,0.7,0.65,0.6,0.55,0.5,0.45, 0.4、0.35、0.3、0.25、0.2、0.15、0.1、0.05）；In hydrogen（H2）Under atmosphere, at 1080 DEG C, TMGa conducts are passed through Group III source, NH₃2 μ m-thick u-GaN semi-insulating layers 106 are grown as group V source.Then, in 1080 DEG C, H₂Under atmosphere, be passed through TMGa, TMAl is as group III source, NH₃As group V source, SiH₄The 15nm AlGaN separation layers 107 to undope are grown as n-shaped doped source, 20nm mixes the AlGaN potential barrier 108 that the AlGaN and 20nm of Si undope.

Embodiment 2

Using Aixtron companies, the vertical reative cell MOCVD growing systems of close coupling.Trimethyl gallium is used in growth course （TMGa）, trimethyl aluminium（TMAl）As group III source, ammonia（NH₃）As group V source, silane（SiH₄）As n-shaped doped source, two Luxuriant magnesium（Cp₂Mg）As p-type doped source, Si substrates 201 are heated to 1080 DEG C in MOCVD reative cells first, in H₂Atmosphere Under, using TMGa, TMAl as group III source, NH₃As group V source, 0.1 micron of thickness AlN nucleating layer is grown；Then, 1080 ℃、H₂Under atmosphere, TMAl, TMGa are passed through as group III source, NH₃As group V source, 0.5 micron of thickness AlGaN seed layer 202 is grown. Using Low Pressure Chemical Vapor Deposition（LPCVD）Grow the multilayer carbon nanotube of marshalling.In growth course, using acetylene As carrier gas, while the Fe of 5nm is used as catalyst.Carbon nanotube diameter after growth is 15nm.By growing and weaving, Continuous carbon nano-tube film 203 finally can be formed by carbon nano pipe array arranged in parallel.In 1080 DEG C, H₂Under atmosphere, TMGa, TMAl are passed through as group III source, NH₃1 μm of GaN, which is grown, as group V source merges layer 204；In 1080 DEG C, H₂Under atmosphere, lead to Enter TMGa, TMAl as group III source, NH₃The Al composition gradient gradual changes of the unsymmetric structure in 20 cycles are grown as group V source (3nm)AlN/（3nm）Al_y1Ga_1-y1N/ (3nm) GaN superlattices insert layers, as stress regulation and control layer 205.Wherein Al components y1 with It is by the way that the flow of TMAl is controlled to realize that number of superlattice cycles increase, which is reduced from 1 staged to 0.05, Al component stepped changes,（With Number of superlattice cycles increase Al components y₁Be followed successively by 1,0.95,0.9,0.85,0.8,0.75,0.7,0.65,0.6,0.55,0.5, 0.45、0.4、0.35、0.3、0.25、0.2、0.15、0.1、0.05）；In hydrogen（H2）Under atmosphere, at 1080 DEG C, it is passed through TMGa is as group III source, NH₃2 μ m-thick u-GaN semi-insulating layers 206 are grown as group V source.Then, in 1080 DEG C, H₂Under atmosphere, TMGa, TMAl are passed through as group III source, NH₃As group V source, SiH₄The 15nm AlGaN to undope as n-shaped doped source growth Separation layer 207,20nm mix the AlGaN potential barrier 208 that the AlGaN and 20nm of Si undope.

Such as Fig. 3（b）、（c）Shown in SEM photograph, using technology in the present invention：Carbon nanotubes as periodic dielectric mask, Using selective area epitaxial（SAG）Method, and layer structure is regulated and controled by design stress, obtain no cracking, the AlGaN/ of high-crystal quality GaN HEMT devices.Without using carbon nanotube as periodic dielectric mask and without using Al_y1Ga_1-y1N/GaN surpasses Lattice or AlN/Al_y1Ga_1-y1There is apparent tortoise on AlGaN/GaN HEMT devices surface prepared by the commonsense method of N/GaN superlattices It splits.

Embodiment described above is merely illustrative of the invention's technical idea and feature, and description is more specific and detailed, Its object is to which those of ordinary skill in the art is enable to understand present disclosure and are implemented according to this, therefore cannot be only with this Come limit the present invention the scope of the claims, but can not therefore and be interpreted as limitation of the scope of the invention.It should be pointed out that pair For those of ordinary skill in the art, without departing from the inventive concept of the premise, several deformations can also be made and changed Into that is, all variations made according to disclosed spirit should be covered in the scope of the claims of the present invention.

Claims (6)

1. the method that one kind prepares high electron mobility field-effect transistor (HEMT) on large scale Si substrates, uses trimethyl Gallium（TMGa）, trimethyl aluminium（TMAl）As group III source, ammonia（NH₃）As group V source, silane（SiH₄）As n-shaped doped source, On a si substrate, first growing AIN nucleating layer and AlGaN seed layers；It is creative on this basis to use carbon nanotubes as the cycle Property medium mask, using selective area epitaxial（SAG）Method obtains no cracking, the GaN epitaxial layer of high-crystal quality, and further makes Standby AlGaN/GaN HEMT devices；This method comprises the following steps：

Step 1, in Metal Organic Vapor epitaxial reactor, in hydrogen（H₂）Under atmosphere, on a si substrate, temperature At 1000 DEG C~1500 DEG C, TMAl is passed through as group III source, NH₃As group V source, 0.1~0.5 micron of thickness AlN nucleation is grown Layer；On this basis, at 1000 DEG C~1500 DEG C of temperature, TMAl, TMGa are passed through as group III source, NH₃As group V source, growth 0.1~1 micron of thickness AlGaN seed layer；

Step 2, using Low Pressure Chemical Vapor Deposition（LPCVD）Grow the multilayer carbon nanotube of marshalling；In growth course In, using acetylene as carrier gas, while using Fe as catalyst；Carbon nanotube diameter after growth is 15nm；Pass through growth And braiding, continuous carbon nano-tube film is finally formed by carbon nano pipe array arranged in parallel；

Step 3, in hydrogen（H₂）Under atmosphere, at 1000 DEG C~1500 DEG C, TMGa is passed through as group III source, NH₃As V races Source grows 0.1~1 micron of GaN and merges layer；

Step 4, in hydrogen（H₂）Under atmosphere, at 1000 DEG C~1500 DEG C, TMGa, TMAl are passed through as group III source, NH₃Make The Al of the Al composition gradient gradual changes of multicycle unsymmetric structure is grown for group V source_y1Ga_1-y1N/GaN superlattices insert layers, as should Power regulates and controls layer；

Step 5, in hydrogen（H₂）Under atmosphere, at 1050 DEG C~1200 DEG C, TMGa is passed through as group III source, NH₃As V races Source grows 2~4 microns of thickness μ-GaN semi-insulating layers；Then TMGa, TMAl are passed through as group III source, NH₃As group V source, SiH₄Make For 5nm~15nm AlGaN separation layers for undoping of n-shaped doped source growth, 10nm~20nm mixes the AlGaN of Si and undopes AlGaN potential barrier.

2. one kind according to claim 1 prepares high electron mobility field-effect transistor on large scale Si substrates (HEMT) method, it is characterised in that：Continuous carbon nano-tube film is formed by carbon nano pipe array periodically arranged in parallel As periodic dielectric mask；Selective area epitaxial is used on this basis（SAG）Method, using GaN in new carbon nanotubes medium The selectivity grown on mask and AlGaN seed layers is limited in GaN epitaxial layer in the region of no medium mask and grows, shape Into discrete window, the tensile stress in entire epitaxial layer is discharged.

3. one kind according to claim 1 prepares high electron mobility field-effect transistor on large scale Si substrates (HEMT) method, it is characterised in that：The stress regulation and control layer uses the Al of multicycle Al content gradually variational_y1Ga_1-y1N/GaN surpasses Lattice, wherein, Al components y₁As the increase of stress regulation and control layer number of superlattice cycles is reduced from 1 gradient to 0（0≤y1≤1)；It is super Lattice period number is 1~20.

4. one kind according to claim 1 prepares high electron mobility field-effect transistor on large scale Si substrates (HEMT) method, it is characterised in that：The stress regulation and control layer uses the Al of multicycle Al content gradually variational_y1Ga_1-y1N/GaN surpasses Lattice, the wherein thickness of superlattices well layer GaN are 1~5nm, superlattices Al_y1Ga_1-y1The thickness of N barrier layer is 1~5nm.

5. one kind according to claim 1 prepares high electron mobility field-effect transistor on large scale Si substrates (HEMT) method, it is characterised in that：The stress regulation and control layer uses the AlN/ of multicycle unsymmetric structure Al content gradually variationals Al_y1Ga_1-y1N/GaN superlattices, wherein Al components y₁With stress regulation and control layer number of superlattice cycles increase from 1 gradient reduce to 0（0≤y1≤1), number of superlattice cycles are 1~20.

6. one kind according to claim 1 prepares high electron mobility field-effect transistor on large scale Si substrates (HEMT) method, it is characterised in that：The stress regulation and control layer uses the AlN/ of multicycle unsymmetric structure Al content gradually variationals Al_y1Ga_1-y1N/GaN superlattices, the wherein thickness of superlattices well layer GaN are 1~5nm, superlattices Al_y1Ga_1-y1The thickness of N barrier layer For 1~5nm, the thickness of superlattices AlN insert layers is 1~5nm.