In situ optical monitoring of AlGaN thickness and composition during MOVPE growth of AlGaN/GaN microwave HFETs

被引:21
作者
Balmer, RS [1 ]
Pickering, C [1 ]
Kier, AM [1 ]
Birbeck, JCH [1 ]
Saker, M [1 ]
Martin, T [1 ]
机构
[1] DERA Malvern, Malvern WR14 3PS, Worcs, England
关键词
characterization; metalorganic vapor phase epitaxy; nitrides; semiconducting III-V materials;
D O I
10.1016/S0022-0248(01)01254-4
中图分类号
O7 [晶体学];
学科分类号
0702 ; 070205 ; 0703 ; 080501 ;
摘要
Real-time spectral reflectometry has been implemented to monitor the MOVPE growth of AlGaN/GaN microwave HFET structures. The aim is to monitor and control the thickness and composition of the thin AlGaN layer during growth. In order to extract useful information from the in situ spectra the optical constants of AlGaN as a function of alloy composition are required at the growth temperature (similar to 1050 degreesC). As the first step to obtaining the high temperature optical constants, a room temperature spectroscopic ellipsometry study (energy range 1.65-4.95 eV) has been carried out on thin AlGaN films of various thickness (30 and 100 nm) and aluminium content (0.15 and 0.25). The multilayer model of each sample from the ellipsometry study is used to generate a reflectance spectrum which is compared with the in situ spectral reflectometry spectrum of the same sample acquired at room temperature to verify the technique. Further work is in progress to model the bandgap and optical constants of GaN and AlGaN at growth temperature. Crown Copyright (C) 2001 Published by Elsevier Science B.V. All rights reserved.
引用
收藏
页码:361 / 367
页数:7
相关论文
共 18 条
[1]   EFFECTS OF AIN BUFFER LAYER ON CRYSTALLOGRAPHIC STRUCTURE AND ON ELECTRICAL AND OPTICAL-PROPERTIES OF GAN AND GA1-XALXN(0-LESS-THAN-X-LESS-THAN-OR-EQUAL-TO-0.4) FILMS GROWN ON SAPPHIRE SUBSTRATE BY MOVPE [J].
AKASAKI, I ;
AMANO, H ;
KOIDE, Y ;
HIRAMATSU, K ;
SAWAKI, N .
JOURNAL OF CRYSTAL GROWTH, 1989, 98 (1-2) :209-219
[2]  
BALMER RS, IN PRESS
[3]  
BALMER RS, 2001, UNPUB EMRS 2001 SPRI
[4]   Optical constants of epitaxial AlGaN films and their temperature dependence [J].
Brunner, D ;
Angerer, H ;
Bustarret, E ;
Freudenberg, F ;
Hopler, R ;
Dimitrov, R ;
Ambacher, O ;
Stutzmann, M .
JOURNAL OF APPLIED PHYSICS, 1997, 82 (10) :5090-5096
[5]  
EDGAR JH, 1999, PROPERTIES PROCESSIN, P7
[6]  
HANSER AD, 1999, PROPERTIES PROCESSIN, P248
[7]  
JOHS B, OPTICAL METROLO CR 2, V72
[8]   Influence of sapphire nitridation on properties of gallium nitride grown by metalorganic chemical vapor deposition [J].
Keller, S ;
Keller, BP ;
Wu, YF ;
Heying, B ;
Kapolnek, D ;
Speck, JS ;
Mishra, UK ;
DenBaars, SP .
APPLIED PHYSICS LETTERS, 1996, 68 (11) :1525-1527
[9]  
KIER A, UNPUB
[10]   IN-SITU SPECTRAL REFLECTANCE MONITORING OF III-V EPITAXY [J].
KILLEEN, KP ;
BREILAND, WG .
JOURNAL OF ELECTRONIC MATERIALS, 1994, 23 (02) :179-183