CN101964363A - Metal-semiconductor field effect transistor with stepped buffer layer structure - Google Patents

Metal-semiconductor field effect transistor with stepped buffer layer structure Download PDF

Info

Publication number
CN101964363A
CN101964363A CN 201010246860 CN201010246860A CN101964363A CN 101964363 A CN101964363 A CN 101964363A CN 201010246860 CN201010246860 CN 201010246860 CN 201010246860 A CN201010246860 A CN 201010246860A CN 101964363 A CN101964363 A CN 101964363A
Authority
CN
China
Prior art keywords
buffer layer
gate electrode
resilient coating
stepped
effect transistor
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN 201010246860
Other languages
Chinese (zh)
Inventor
邓小川
张波
王易
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
University of Electronic Science and Technology of China
Original Assignee
University of Electronic Science and Technology of China
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by University of Electronic Science and Technology of China filed Critical University of Electronic Science and Technology of China
Priority to CN 201010246860 priority Critical patent/CN101964363A/en
Publication of CN101964363A publication Critical patent/CN101964363A/en
Pending legal-status Critical Current

Links

Images

Landscapes

  • Junction Field-Effect Transistors (AREA)

Abstract

The invention relates to a MESFET (Metal-Semiconductor Field Effect Transistor) with a stepped buffer layer structure, belonging to the technical field of power semiconductor devices. The buffer layer becomes stepped by etching an epitaxial buffer layer of the device, so that an active layer epitaxially growing on the buffer layer has varying channel thickness. The thickest part of the buffer layer is right below a gate electrode, and the thickness of the buffer layer below both sides of the gate electrode is small. The active layer is reversely stepped, the thinnest part of the active layer is right below the gate electrode, and the thickness of the active layer below both sides of the gate electrode is large. The MESFET with the stepped buffer layer structure has the advantages of good DC characteristic, frequency characteristic and output power density, and is applicable to microwave and high power fields.

Description

A kind of metal-semiconductor field effect transistor with stepped buffer layer structure
Technical field
The invention belongs to the power semiconductor technical field, relate to metal-semiconductor field effect transistor, be specifically related to be applied in metal-semiconductor field effect transistor under microwave, the large-power occasions (Metal-Semiconductor-Field-Effect-Transistor, MESFET).
Technical background
In recent years, along with the fast development of microelectric technique, and the active demand of association areas such as Aero-Space, electronic countermeasures and radar communication, development novel high-frequency, high power semiconductor device are subjected to people and more and more pay close attention to.Bipolar transistor (Bipolar-Junction-Transistor, BJT) and power metal oxide semiconductor field-effect transistor (Metal-Oxide-Semiconductor-Field-Effect-Transistor MOSFET) is widely used on the higher power applications.BJT is less sub-device, and its power handling capability can be restricted under higher operational frequency.MOSFET compares with MESFET, and its grid capacitance is bigger, has influenced its frequency characteristic, and the manufacturing process complexity of MOSFET.And the simple MESFET of manufacturing process makes it can be applied in the high-frequency microwave field better because its grid adopts Schottky (Schottky) structure.
Because the good characteristic of carbofrax material, in commercial and military communication field, feasible metal-semiconductor field effect transistor based on carbofrax material becomes high-power, well select for one under high frequency and high temperature are used, as document T.Paul Chow: ' High-voltage SiC and GaN power devices ', Microelectronic Engineering, 2006, Vol.83, No.1, pp.112-122. and document M.Rosker: ' Wide Bandgap and MMICs ', III-Vs Review, 2005, Vol.18, No.4, pp.24-25. is described.Key parameters such as the OFF state puncture voltage of the Performance And Reliability of MESFET device and device and parasitic capacitance are closely related, and these key parameters depend on the structure and the concentration of resilient coating strongly.Therefore, the design of device resilient coating has important function aspect the raising device performance.Need consider a principle when carrying out layer buffer design: resilient coating will guarantee essential raceway groove and substrate isolation, can not introduce too big parasitic capacitance and drain leakage current simultaneously, in order to avoid reduce the high frequency performance of device.Though reported a large amount of SiC MESFET structures and various prioritization scheme in a lot of documents, also fewer to the research of SiC MESFET buffer layer structure.
SiC MESFET generally adopts the semi-insulating substrate of SiC, resilient coating, active layer and four layers of epitaxial structure of cap layer at present.Conventional structure as shown in Figure 1, etched recesses on whole active layer 15 forms recess channel, is called chase (channel recess) structure.The SiC MESFET device DC characteristic of this structure and frequency characteristic remain further to be improved, and use to adapt under microwave frequency band, the large-power occasions.
Summary of the invention
The invention provides a kind of MESFET device with stepped buffer layer structure.This device is by the etching epitaxial buffer layer, and it is stepped that resilient coating is presented, and then make that epitaxially grown active layer has the channel thickness of variation on resilient coating.Stepped buffer layer structure between grid source and the grid leak has not only improved the device drain saturation current, and has improved the device high frequency performance.In ladder resilient coating MESFET structure, on the one hand, the resilient coating (corresponding to the thicker active layer of gate electrode down either side) that the gate electrode down either side is thin has reduced the parasitic series resistance of device, thereby increases the output power density of device; On the other hand, the thicker resilient coating (corresponding to the thin active layer in gate electrode below) in gate electrode below has guaranteed the enough device grid length and the ratio of channel thickness, thereby has avoided short-channel effect and drain electrode potential barrier to reduce effect.Simultaneously, the raceway groove internal electric field that stepped buffer layer structure has been modulated the gate edge side distributes, and has increased g m/ C GsRatio can significantly improve the high frequency small-signal behaviour of device.
Technical solution of the present invention is as follows:
A kind of metal-semiconductor field effect transistor with stepped buffer layer structure, extremely shown in Figure 7 as Fig. 2, comprise the highly doped ohmic contact regions 14A under semi-insulating substrate 17, resilient coating 16, active layer 15, the source electrode, the highly doped ohmic contact regions 14B under the drain electrode, and source electrode 11, drain electrode 12 and gate electrode 13.Described resilient coating 16 is stepped, and wherein resilient coating 16 thickness the best parts appear under the gate electrode 13, and the buffer layer thickness of gate electrode 13 down either side is less; With described stepped resilient coating 16 accordingly, described active layer 15 is the inverted steps shape, wherein the part of active layer 15 thickness minimums appears under the gate electrode 13, and active layer 15 thickness of gate electrode 13 down either side are bigger.
MESFET with stepped buffer layer structure provided by the invention, wherein the semiconductor layer material except that electrode can adopt carborundum (SiC), silicon (Si) or gallium nitride (GaN) etc.; And electrode material can be Titanium, metallic nickel or Ti-Ni alloy.
Stepped resilient coating can be modulated the Electric Field Distribution of raceway groove inside and increase g m/ C GsRatio, thereby improve the frequency characteristic of MESFET device.The major parameter of reflection MESFET device frequency characteristic is cut-off frequency f TWith maximum oscillation frequency f Max, provide by following equation:
f T = g m 2 π C gs f max = f T 2 R ds R g
According to f TAnd f MaxCalculating formula as can be seen, g m/ C GsThe increase of ratio can improve f TAnd f MaxMESFET with stepped buffer layer structure disclosed in this invention utilizes this principle to improve cut-off frequency f just TAnd f Max.
Stepped resilient coating can effectively reduce the parasitic series resistance of device active region, thereby increases the drain saturation current of MESFET device.For class-a amplifier, theoretic peak power output density is:
P max = I sat ( V B - V knee ) 8
I wherein SatBe drain saturation current, V BBe puncture voltage, V KneeBe knee voltage.By two-dimensional numerical analysis as can be known, the MESFET drain saturation current of stepped buffer layer structure is greater than conventional structure, and therefore by following formula as can be known, its output power density will increase.
To sum up, beneficial effect of the present invention shows:
The MESFET of ladder buffer layer structure proposed by the invention has good DC characteristic, and frequency characteristic and output power density are applicable to microwave, high-power field.Stair-stepping resilient coating (corresponding to the active layer of inverted steps shape) can effectively reduce the parasitic series resistance of device, thereby improves the drain saturation current of MESFET device, has guaranteed high output power density.Simultaneously the raceway groove internal electric field that stepped resilient coating (corresponding to the active layer of inverted steps shape) can also modulation grid edge distributes, thereby increases g m/ C GsRatio, significantly improve the high frequency small-signal behaviour of MESFET device.
Description of drawings
Fig. 1 is the conventional structure schematic diagram with MESFET device of resilient coating.
Wherein 11 is the source electrode, and 12 is drain electrode, and 13 is gate electrode, and 14A is the highly doped ohmic contact regions under the electrode of source, and 14B is the highly doped ohmic contact regions under the drain electrode, and 15 is active layer, and 16 is resilient coating, and 17 is semi-insulating substrate.
Fig. 2 to Fig. 6 is the structural representation with MESFET of stepped buffer layer structure provided by the invention.Fig. 2 to Fig. 6 has provided the different implementations with MESFET of stepped buffer layer structure provided by the invention, and wherein difference is that the shape of resilient coating 16 is different.
Fig. 7 and Fig. 8 are the have MESFET of stepped buffer layer structure and the DC I-V characteristic of the MESFET of conventional structure (structure shown in Figure 1) and the contrasts of frequency characteristic of the present invention.Wherein, the curve representation of the filled symbols MESFET Devices Characteristics with ladder buffer layer structure of the present invention, the MESFET Devices Characteristics of the curve representation conventional structure of open symbols.
Embodiment
A kind of metal-semiconductor field effect transistor with stepped buffer layer structure, extremely shown in Figure 7 as Fig. 2, comprise the highly doped ohmic contact regions 14A under semi-insulating substrate 17, resilient coating 16, active layer 15, the source electrode, the highly doped ohmic contact regions 14B under the drain electrode, and source electrode 11, drain electrode 12 and gate electrode 13.Described resilient coating 16 is stepped, and wherein resilient coating 16 thickness the best parts appear under the gate electrode 13, and the buffer layer thickness of gate electrode 13 down either side is less; With described stepped resilient coating 16 accordingly, described active layer 15 is the inverted steps shape, wherein the part of active layer 15 thickness minimums appears under the gate electrode 13, and active layer 15 thickness of gate electrode 13 down either side are bigger.
Other embodiments of the invention, the width that can change concentration, thickness and the different-thickness zone of resilient coating is according to actual needs realized.Fig. 2 to Fig. 6 has provided the different implementations with MESFET of stepped buffer layer structure provided by the invention, and wherein difference is that the shape of resilient coating 16 is different.
As shown in Figure 2, wherein said resilient coating 16 has two ladders in grid source one side, has a ladder in grid leak one side.
As shown in Figure 3, wherein said resilient coating 16 has a ladder in grid source one side, has two ladders in grid leak one side.
As shown in Figure 4, wherein said resilient coating 16 has two ladders in grid source one side, also has two ladders in grid leak one side.
As shown in Figure 6, wherein said resilient coating 16 has a ladder in grid source one side, also has a ladder in grid leak one side.
Shown in Fig. 2,3,4 and 6, the lateral dimension of the part that wherein said resilient coating 16 is the thickest equals the lateral dimension of gate electrode 13; Accordingly, the lateral dimension of the part that described active layer 15 is the thinnest equals the lateral dimension of gate electrode 13.As shown in Figure 5, the lateral dimension of the part that wherein said resilient coating 16 is the thickest is less than the lateral dimension of gate electrode 13; Accordingly, the lateral dimension of the part that described active layer 15 is the thinnest is less than the lateral dimension of gate electrode 13.
Specific embodiment of the present invention is the MESFET that adopts ladder buffer layer structure shown in Figure 2.Active layer is n (p) type, and resilient coating is p (n) type, and semi-conducting material is SiC, and gate electrode metal is a nickel.
Shown in Figure 7 is that two kinds of structures with above-mentioned parameter are carried out the DC I-V curve that two-dimensional numerical analysis obtains, and wherein the filled symbols curve representation is structure proposed by the invention, the open symbols curve representation be conventional structure (as shown in Figure 1).The drain saturation current of structure proposed by the invention is obviously greater than conventional structure as can be seen.
Shown in Figure 8 is high frequency small-signal behaviour curve, and wherein the filled symbols curve representation is structure proposed by the invention, the open symbols curve representation be conventional structure (as shown in Figure 1).The cut-off frequency of structure proposed by the invention and maximum frequency of oscillation all are higher than conventional structure as can be seen.
The MESFET of ladder buffer layer structure proposed by the invention has good DC characteristic, and frequency characteristic and output power density are applicable to microwave, high-power field.Stair-stepping resilient coating (corresponding to the active layer of inverted steps shape) can effectively reduce the parasitic series resistance of device, thereby improves the drain saturation current of MESFET device, has guaranteed high output power density.Simultaneously the raceway groove internal electric field that stepped resilient coating (corresponding to the active layer of inverted steps shape) can also modulation grid edge distributes, thereby increases g m/ C GsRatio, significantly improve the high frequency small-signal behaviour of MESFET device.

Claims (8)

1. metal-semiconductor field effect transistor with stepped buffer layer structure, comprise the highly doped ohmic contact regions (14A) under semi-insulating substrate (17), resilient coating (16), active layer (15), the source electrode, the highly doped ohmic contact regions (14B) under the drain electrode, and source electrode (11), drain electrode (12) and gate electrode (13); It is characterized in that described resilient coating (16) is stepped, wherein resilient coating (16) thickness the best part appears under the gate electrode (13), and the buffer layer thickness of gate electrode (13) down either side is less; With described stepped resilient coating (16) accordingly, described active layer (15) is the inverted steps shape, wherein the part of active layer (15) thickness minimum appears under the gate electrode (13), and active layer (15) thickness of gate electrode (13) down either side is bigger.
2. the metal-semiconductor field effect transistor with stepped buffer layer structure according to claim 1 is characterized in that, the semiconductor layer material except that electrode adopts carborundum, silicon or gallium nitride; And electrode material is Titanium, metallic nickel or Ti-Ni alloy.
3. the metal-semiconductor field effect transistor with stepped buffer layer structure according to claim 1 and 2 is characterized in that, described resilient coating (16) has two ladders in grid source one side, has a ladder in grid leak one side.
4. the metal-semiconductor field effect transistor with stepped buffer layer structure according to claim 1 and 2 is characterized in that, described resilient coating (16) has a ladder in grid source one side, has two ladders in grid leak one side.
5. the metal-semiconductor field effect transistor with stepped buffer layer structure according to claim 1 and 2 is characterized in that, described resilient coating (16) has two ladders in grid source one side, also has two ladders in grid leak one side.
6. the metal-semiconductor field effect transistor with stepped buffer layer structure according to claim 1 and 2 is characterized in that, described resilient coating (16) has a ladder in grid source one side, also has a ladder in grid leak one side.
7. according to arbitrary metal-semiconductor field effect transistor in the claim 3 to 6, it is characterized in that the lateral dimension of the part that described resilient coating (16) is the thickest equals the lateral dimension of gate electrode (13) with stepped buffer layer structure; Accordingly, the lateral dimension of the part that described active layer (15) is the thinnest equals the lateral dimension of gate electrode (13).
8. according to arbitrary metal-semiconductor field effect transistor in the claim 3 to 6, it is characterized in that the lateral dimension of the part that described resilient coating (16) is the thickest is less than the lateral dimension of gate electrode (13) with stepped buffer layer structure; Accordingly, the lateral dimension of the part that described active layer (15) is the thinnest is less than the lateral dimension of gate electrode (13).
CN 201010246860 2010-08-06 2010-08-06 Metal-semiconductor field effect transistor with stepped buffer layer structure Pending CN101964363A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN 201010246860 CN101964363A (en) 2010-08-06 2010-08-06 Metal-semiconductor field effect transistor with stepped buffer layer structure

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN 201010246860 CN101964363A (en) 2010-08-06 2010-08-06 Metal-semiconductor field effect transistor with stepped buffer layer structure

Publications (1)

Publication Number Publication Date
CN101964363A true CN101964363A (en) 2011-02-02

Family

ID=43517179

Family Applications (1)

Application Number Title Priority Date Filing Date
CN 201010246860 Pending CN101964363A (en) 2010-08-06 2010-08-06 Metal-semiconductor field effect transistor with stepped buffer layer structure

Country Status (1)

Country Link
CN (1) CN101964363A (en)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104282764A (en) * 2014-10-28 2015-01-14 西安电子科技大学 4H-SiC metal semiconductor field effect transistor with slope-shaped grid and manufacturing method
CN104201208B (en) * 2014-08-26 2016-11-30 电子科技大学 A kind of constant current JFET device and manufacture method thereof
CN106910775A (en) * 2017-03-20 2017-06-30 西安电子科技大学 A kind of 4H SiC metal-semiconductor field effect transistors with many depression cushions
CN107068762A (en) * 2017-03-20 2017-08-18 西安电子科技大学 The preparation method of 4H SiC metal semiconductor field effect transis with many depression cushions
CN108807528A (en) * 2018-05-24 2018-11-13 西安电子科技大学 A kind of novel microwave GaN high electron mobility transistor
CN113206156A (en) * 2021-04-28 2021-08-03 青岛科技大学 Double-groove stepped buffer gate 4H-SiC metal semiconductor field effect transistor and modeling simulation method

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS535581A (en) * 1976-07-06 1978-01-19 Toshiba Corp Schottky gate type field effect transistor
JPH10125601A (en) * 1996-02-27 1998-05-15 Matsushita Electric Ind Co Ltd Field effect transistor

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS535581A (en) * 1976-07-06 1978-01-19 Toshiba Corp Schottky gate type field effect transistor
JPH10125601A (en) * 1996-02-27 1998-05-15 Matsushita Electric Ind Co Ltd Field effect transistor

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
《IEEE TRANSACTIONS ON ELECTRON DEVICES》 20030707 Ho-Young Cha等 Reduced Trapping Effects and Improved Electrical Performance in buried-gate 4H-SiC MESFETs 第1569页至第1574页 1-8 第50卷, *

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104201208B (en) * 2014-08-26 2016-11-30 电子科技大学 A kind of constant current JFET device and manufacture method thereof
CN104282764A (en) * 2014-10-28 2015-01-14 西安电子科技大学 4H-SiC metal semiconductor field effect transistor with slope-shaped grid and manufacturing method
CN104282764B (en) * 2014-10-28 2017-10-13 西安电子科技大学 4H SiC metal-semiconductor field effect transistors and preparation method with domatic grid
CN106910775A (en) * 2017-03-20 2017-06-30 西安电子科技大学 A kind of 4H SiC metal-semiconductor field effect transistors with many depression cushions
CN107068762A (en) * 2017-03-20 2017-08-18 西安电子科技大学 The preparation method of 4H SiC metal semiconductor field effect transis with many depression cushions
CN106910775B (en) * 2017-03-20 2020-01-10 西安电子科技大学 4H-SiC metal semiconductor field effect transistor with multi-concave buffer layer
CN108807528A (en) * 2018-05-24 2018-11-13 西安电子科技大学 A kind of novel microwave GaN high electron mobility transistor
CN113206156A (en) * 2021-04-28 2021-08-03 青岛科技大学 Double-groove stepped buffer gate 4H-SiC metal semiconductor field effect transistor and modeling simulation method

Similar Documents

Publication Publication Date Title
CN100521236C (en) Metal-semiconductor field effect transistor with source-drain double-concave structure
Donato et al. Diamond power devices: state of the art, modelling, figures of merit and future perspective
CN105283958B (en) The cascode structure of GaN HEMT
US7525130B2 (en) Polarization-doped field effect transistors (POLFETS) and materials and methods for making the same
US8338871B2 (en) Field effect transistor with electric field and space-charge control contact
CN104201202B (en) Gallium-nitride-based heterostructure field effect transistor with composite barrier layers
CN104395993A (en) Semiconductor device
EP2887400A1 (en) Field effect transistor
CN101964363A (en) Metal-semiconductor field effect transistor with stepped buffer layer structure
Zhou et al. Schottky-ohmic drain AlGaN/GaN normally off HEMT with reverse drain blocking capability
CN102820325A (en) Gallium nitride-based hetero-junction field effect transistor with back electrode structure
Hou et al. High linearity and high power performance with barrier layer of sandwich structure and Al0. 05GaN back barrier for X-band application
Hilt et al. Lateral and vertical power transistors in GaN and Ga2O3
CN110690273B (en) Transverse GaN-based enhanced junction field effect transistor device and preparation method thereof
Zhou et al. Ultrathin-barrier AlGaN/GaN hybrid-anode-diode with optimized barrier thickness for zero-bias microwave mixer
Liu et al. Demonstration of β-Ga 2 O 3 heterojunction gate field-effect rectifier
Jessen et al. Gallium oxide technologies and applications
CN108831932B (en) Transverse MIS-Schottky mixed anode diode of gallium nitride
Ture et al. Performance and parasitic analysis of sub-micron scaled tri-gate AlGaN/GaN HEMT design
US20050269661A1 (en) Lateral channel transistor
CN113363319B (en) Normally-off gallium oxide based MIS-HFET device
CN109742144A (en) A kind of enhanced MISHEMT device of slot grid and preparation method thereof
US20210399121A1 (en) Novel approach to controlling linearity in n-polar gan mishemts
Chumbes et al. Microwave performance of AlGaN/GaN high electron mobility transistors on Si (111) substrates
Yadava et al. RF performance evaluation of p-type NiO-pocket based β-Ga2O3/black phosphorous heterostructure MOSFET

Legal Events

Date Code Title Description
C06 Publication
PB01 Publication
C10 Entry into substantive examination
SE01 Entry into force of request for substantive examination
C02 Deemed withdrawal of patent application after publication (patent law 2001)
WD01 Invention patent application deemed withdrawn after publication

Application publication date: 20110202