Engineering of an insulating buffer and use of AlN interlayers: two optimisations for AlGaN-GaNHEMT-like structures

被引:68
作者
Bougrioua, Z
Moerman, I
Nistor, L
Van Daele, B
Monroy, E
Palacios, T
Calle, F
Leroux, M
机构
[1] CNRS, CRHEA, F-06560 Valbonne, France
[2] Univ Ghent, IMEC, INTEC, B-9000 Ghent, Belgium
[3] Univ Antwerp, Dept Phys, EMAT, B-2020 Antwerp, Belgium
[4] UPM, Inst Sistemas Optoelect & Microtecnol, Madrid 28040, Spain
来源
PHYSICA STATUS SOLIDI A-APPLICATIONS AND MATERIALS SCIENCE | 2003年 / 195卷 / 01期
关键词
D O I
10.1002/pssa.200306305
中图分类号
T [工业技术];
学科分类号
08 ;
摘要
The semi-insulating character of GaN epitaxial layers can be achieved by the control of the early stages of growth on the substrate. Adding two low temperature (LT) AlN interlayers is a technique enough powerful to reduce threading dislocation densities by up to one order of magnitude. A compressive strain as high as 2.8 x 10(-3) is induced in the uppermost GaN epilayer. The global structure is kept semi-insulating so that,it is a perfect template for undoped AlGaN-GaN HEMTs (High Electron Mobility Transistors). HEMTs with interlayers present better two dimensional electron gas (2DEG) properties: up to 20% higher carrier density (n(S)) and 40% higher mobility. Typically n(S) is as high as 1.7 x 10(13) cm(-2) for a record mobility of 1200 cm(2)/Vs. The improvement of the mobility can be correlated to the reduction of nano-scale V-shaped defects in the AlGaN (less morphological-relaxation). The improvement of n(S) could be explained by the higher piezo-doping resulting from GaN extra-compression and AlGaN weaker relaxation. As a consequence, the DC transistors characteristics are improved: in 2 mum gate transistors, the maximum current and transconductance are increased by up to 80% and 20%, respectively, and could be extrapolated to values as high as 1500 mA/mm and 250 mS/mm for 0.2 mum gate devices.
引用
收藏
页码:93 / 100
页数:8
相关论文
共 18 条
[1]   Stress and defect control in GaN using low temperature interlayers [J].
Amano, H ;
Iwaya, M ;
Kashima, T ;
Katsuragawa, M ;
Akasaki, I ;
Han, J ;
Hearne, S ;
Floro, JA ;
Chason, E ;
Figiel, J .
JAPANESE JOURNAL OF APPLIED PHYSICS PART 2-LETTERS & EXPRESS LETTERS, 1998, 37 (12B) :L1540-L1542
[2]  
Beaumont B, 2001, PHYS STATUS SOLIDI B, V227, P1, DOI 10.1002/1521-3951(200109)227:1<1::AID-PSSB1>3.0.CO
[3]  
2-Q
[4]  
Bougrioua Z, 2001, PHYS STATUS SOLIDI B, V228, P625, DOI 10.1002/1521-3951(200111)228:2<625::AID-PSSB625>3.0.CO
[5]  
2-I
[6]   Material optimisation for AlGaN/GaN HFET applications [J].
Bougrioua, Z ;
Moerman, I ;
Sharma, N ;
Wallis, RH ;
Cheyns, J ;
Jacobs, K ;
Thrush, EJ ;
Considine, L ;
Beanland, R ;
Farvacque, JL ;
Humphreys, C .
JOURNAL OF CRYSTAL GROWTH, 2001, 230 (3-4) :573-578
[7]   Reduction of threading dislocation density in GaN using an intermediate temperature interlayer [J].
Bourret-Courchesne, ED ;
Kellermann, S ;
Yu, KM ;
Benamara, M ;
Liliental-Weber, Z ;
Washburn, J ;
Irvine, SJC ;
Stafford, A .
APPLIED PHYSICS LETTERS, 2000, 77 (22) :3562-3564
[8]  
CALLE F, 2002, UNPUB J MAT SCI MAT
[9]  
FARVACQUE JL, 2002, UNPUB J PHYS CONDENS
[10]   Properties of Si-doped GaN films grown using multiple AlN interlayers [J].
Koleske, DD ;
Twigg, ME ;
Wickenden, AE ;
Henry, RL ;
Gorman, RJ ;
Freitas, JA ;
Fatemi, M .
APPLIED PHYSICS LETTERS, 1999, 75 (20) :3141-3143