CN206250198U

CN206250198U - A kind of GaN base transistor with high electronic transfer rate epitaxial structure

Info

Publication number: CN206250198U
Application number: CN201621416681.0U
Authority: CN
Inventors: 孔欣
Original assignee: Chengdu Hiwafer Technology Co Ltd
Current assignee: Chengdu Hiwafer Technology Co Ltd
Priority date: 2016-12-22
Filing date: 2016-12-22
Publication date: 2017-06-13
Anticipated expiration: 2026-12-22

Abstract

The utility model provides a kind of GaN base transistor with high electronic transfer rate epitaxial structure, include substrate, AlN nucleating layers, GaN cushions, GaN channel layers, AlN insert layers and InN/AlN superlattices barrier layers successively from top to bottom, the InN/AlN superlattices barrier layer includes the potential barrier unit of multiple vertical-growths, and each potential barrier unit includes InN layers and AlN layers be grown on InN layers.The utility model uses InN/AlN superlattices barrier layers, can reach barrier layer and be matched completely with the lattice of GaN cushions, eliminates piezo-electric effect, improves device reliability；And possess stronger spontaneous polarization effect, high density two-dimensional electron gas can be produced, device current density will be higher than using the device of AlGaN potential barriers；The InN/AlN superlattices potential barrier of low thickness can also produce the two-dimensional electron gas of higher density, be especially suitable for the millimetric wave device application of GaN.

Description

A kind of GaN base transistor with high electronic transfer rate epitaxial structure

Technical field

The utility model is related to technical field of semiconductors, and in particular to outside a kind of GaN base transistor with high electronic transfer rate Prolong structure.

Background technology

After silicon（Si）, GaAs（GaAs）And indium phosphide（InP）After semi-conducting material, with gallium nitride（GaN）And carbonization Silicon（SiC）It is the third generation semi-conducting material and device that represent, domestic and international solid state microwave power device was turned into past in 20 years The study hotspot in field, and high speed development has been obtained, gradually move towards commercial applications from experimental study.Especially GaN base electricity high Transport factor transistor（HEMT）, with superiority such as big energy gap, breakdown field strength high, saturated electrons speed high Can, big power density can be exported under high band, it is especially suitable for manufacture high temperature, high pressure, high-frequency large-power microwave, high-power opens The electronic devices such as pass, in satellite, radio communication base station, radar detection, automotive electronics, power transmission and monolithic integrated microwave circuit （MMICs）Etc. extensive application in national economy and national defense construction.

Typically AlGaN/GaN HEMT epitaxial structures are successively from lower to upper：Substrate（SiC, sapphire, Si, diamond Deng）, nucleating layer, GaN buffering and channel layer, AlN spaces insert layer, AlGaN potential barrier and optional cap layers.Because lattice loses Match somebody with somebody, can there is larger piezoelectric polarization effect between AlGaN potential barrier and GaN cushions, and this kind of piezoelectric polarization effect is tribute One of the reason for offering high density raceway groove two-dimensional electron gas, another reason is then spontaneous polarization effect specific to nitride-based semiconductor Should.Although having benefited from piezoelectric polarization effect stronger between AlGaN and GaN, AlGaN/GaN hetero-junctions can produce higher density Two-dimensional electron gas, but also move towards extensive commercialization to GaN device and bring huge obstacle：Academic circles at present and industry are generally recognized For, inverse piezoelectric effect is the one of the main reasons that GaN device is degenerated, and the security risk thus brought never is released completely Put.

Not enough in order to improve the above, academia proposes using InAlN barrier layers to replace AlGaN potential barrier, In_0.17Al_0.83N is consistent with GaN lattice parameters, can successfully evade piezoelectric polarization effect, and itself possesses stronger spontaneous Polarity effect, the two-dimensional electron gas of generation are in no way inferior with traditional AlGaN/GaN structures.But high-quality InAlN Crystal is not easy to prepare, and is also not suitable for producing in enormous quantities.

Utility model content

The purpose of this utility model is to provide a kind of GaN base transistor with high electronic transfer rate epitaxial structure, the method Problem above can well be solved.

To reach above-mentioned requirements, the utility model is adopted the technical scheme that：A kind of gallium nitride base high electron mobility is provided Rate transmistor epitaxial structure, includes substrate, AlN nucleating layers, GaN cushions, GaN channel layers, AlN insert layers successively from top to bottom With InN/AlN superlattices barrier layers, the periodicity of the InN/AlN superlattices barrier layer is 3 ~ 5.

Compared with prior art, the utility model this have the advantage that：Using InN/AlN superlattices barrier layers, Ke Yida Matched completely with the lattice of GaN cushions to barrier layer, eliminate piezo-electric effect, improve device reliability；And possess stronger Spontaneous polarization effect, can produce high density two-dimensional electron gas, and device current density will be higher than using the device of AlGaN potential barriers Part；The InN/AlN superlattices potential barrier of low thickness can also produce the two-dimensional electron gas of higher density, be especially suitable for the millimeter wave of GaN Device application.

Brief description of the drawings

Accompanying drawing described herein is used for providing further understanding of the present application, the part of the application is constituted, at this Same or analogous part, the schematic description and description of the application are represented using identical reference number in a little accompanying drawings For explaining the application, the improper restriction to the application is not constituted.In the accompanying drawings：

Fig. 1 is structural representation of the present utility model.

Specific embodiment

To make the purpose, technical scheme and advantage of the application clearer, below in conjunction with drawings and the specific embodiments, to this Application is described in further detail.For the sake of simplicity, eliminated well known to a person skilled in the art some skills in below describing Art feature.

The utility model provides a kind of GaN base transistor with high electronic transfer rate epitaxial structure, as shown in figure 1, from it is lower to On include successively：

Substrate 1：Semi-insulating 4H-SiC, twin polishing, wafer size is 2 ~ 6 inch, and thickness is 400 μm；

AlN nucleating layers 2：Thickness is 50nm, and 500-700 DEG C of growth temperature is lost for alleviating the lattice between GaN and SiC Match somebody with somebody；

GaN cushions 3：Thickness is 1.8 μm, reduce thickness of being tried one's best on the premise of crystal growth quality is ensured, to make Device has less thermal resistance, and growth temperature is 1000-1150 DEG C；GaN cushions 3 mix Fe or C impurity, constitute high-impedance state, Doping concentration is 1 × 1017 ~ 1 × 1018cm-3, and resistivity is in 106-109 Ω cm；

GaN channel layers 4：Thickness 80nm, carrier is concentrated mainly on the layer, and closer to the interface of AlGaN potential barrier Concentration is higher；

AlN insert layers 5：Thickness is 1nm, is effectively reduced the alloy scattering of channel carrier, improves carrier mobility；

InN/AlN superlattices barrier layer 6 by 4 cycles film layer it is alternately stacked constitute, film layer is by InN and AlN groups Into the outermost layer AlN of InN/AlN superlattices barrier layers；Gross thickness is 16.4nm, and each cycle InN thickness is 0.7nm, and AlN is thick It is 3.4nm to spend.

In embodiment described above in addition to GaN cushions are to improve resistivity incorporation Fe or C impurity, the not event of other each layers Meaning doping.

Embodiment described above only represents several embodiments of the present utility model, and its description is more specific and detailed, but The limitation to the utility model scope can not be interpreted as.It should be pointed out that for the person of ordinary skill of the art, Without departing from the concept of the premise utility, various modifications and improvements can be made, these belong to the utility model Protection domain.Therefore protection domain of the present utility model should be defined by the claim.

Claims

1. a kind of GaN base transistor with high electronic transfer rate epitaxial structure, it is characterised in that include successively from top to bottom substrate, AlN nucleating layers, GaN cushions, GaN channel layers, AlN insert layers and InN/AlN superlattices barrier layers, the InN/AlN are super brilliant The periodicity of lattice barrier layer is 3 ~ 5.

2. GaN base transistor with high electronic transfer rate epitaxial structure according to claim 1, it is characterised in that described InN/AlN superlattices barrier layer thickness is 8 ~ 20nm.

3. GaN base transistor with high electronic transfer rate epitaxial structure according to claim 1 and 2, it is characterised in that institute InN thickness degree is stated for 0.5 ~ 1nm, AlN thickness degree is 2 ~ 4nm.

4. GaN base transistor with high electronic transfer rate epitaxial structure according to claim 1, it is characterised in that the lining Bottom is SiC SI-substrates, and thickness is 350-520 μm.

5. GaN base transistor with high electronic transfer rate epitaxial structure according to claim 1, it is characterised in that described The thickness of AlN nucleating layers is 20-100nm.

6. GaN base transistor with high electronic transfer rate epitaxial structure according to claim 1, it is characterised in that described GaN buffer layer thicknesses are 1.6-1.8 μm.

7. GaN base transistor with high electronic transfer rate epitaxial structure according to claim 1, it is characterised in that described The thickness of GaN channel layers is 50-100nm.

8. GaN base transistor with high electronic transfer rate epitaxial structure according to claim 1, it is characterised in that described AlN insert layers thickness is 0.5-1nm.