An atomic force microscopy study of a temperature dependent morphology transition of GaN grown on sapphire by MOCVD

被引:21
作者
de Theije, FK [1 ]
Zauner, ARA [1 ]
Hageman, PR [1 ]
van Enckevort, WJP [1 ]
Larsen, PK [1 ]
机构
[1] Catholic Univ Nijmegen, Fac Sci, Mat Res Inst, NL-6525 ED Nijmegen, Netherlands
关键词
GaN; AFM; morphology; growth kinetics; hollow cores;
D O I
10.1016/S0022-0248(98)00954-3
中图分类号
O7 [晶体学];
学科分类号
0702 ; 070205 ; 0703 ; 080501 ;
摘要
The dependence of the surface morphology of GaN epilayers grown by metal-organic chemical vapour deposition on growth temperature at two different pressures has been studied using atomic force microscopy. First, the theoretical morphology for GaN is derived from the crystal structure. Connected nets were found for the {0 0 0 2}, {1 (1) over bar 0 1} the {1 (1) over bar 0 0} faces. Experimental results show that on Ga terminated GaN films both the (0 0 0 1) and the {1 (1) over bar 0 1} faces are present for a considerable temperature range. are present for a considerable temperature range. At low deposition temperatures the {1 (1) over bar 0 1} faces dominate, at higher growth temperatures the morphology is determined by growth in the [0 0 0 1] direction. It is shown a growth rate parameter, alpha(GaN),proportional to the relative growth rates of the (0 0 0 1) and the {1 (1) over bar 0 1} faces, can be to describe the morphology of the films. The (0 0 0 1) surfaces show growth spirals emerging from screw dislocations. single or double spirals are composed of monoatomic steps. The double steps tend to split at the spiral centres, which be explained by entropic repulsion and a high surface diffusion. Most spiral centres are accompanied by hollow cores, size of which is larger than predicted using Frank's theory. A possible explanation for the large diameter of the hollow is given by the precipitation of vacancies along the dislocations. (C) 1999 Elsevier Science B.V. All rights reserved.
引用
收藏
页码:37 / 47
页数:11
相关论文
共 47 条
[1]   GaN hexagonal microprisms with smooth vertical facets fabricated by selective metalorganic vapor phase epitaxy [J].
Akasaka, T ;
Kobayashi, Y ;
Ando, S ;
Kobayashi, N .
APPLIED PHYSICS LETTERS, 1997, 71 (15) :2196-2198
[2]   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
[3]   METALORGANIC VAPOR-PHASE EPITAXIAL-GROWTH OF A HIGH-QUALITY GAN FILM USING AN AIN BUFFER LAYER [J].
AMANO, H ;
SAWAKI, N ;
AKASAKI, I ;
TOYODA, Y .
APPLIED PHYSICS LETTERS, 1986, 48 (05) :353-355
[4]  
BENNEMA P, 1993, HDB CRYSTAL GROWTH, V1, pCH7
[5]   THE GROWTH OF CRYSTALS AND THE EQUILIBRIUM STRUCTURE OF THEIR SURFACES [J].
BURTON, WK ;
CABRERA, N ;
FRANK, FC .
PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY OF LONDON SERIES A-MATHEMATICAL AND PHYSICAL SCIENCES, 1951, 243 (866) :299-358
[6]   Observation of coreless dislocations in alpha-GaN [J].
Cherns, D ;
Young, WT ;
Steeds, JW ;
Ponce, FA ;
Nakamura, S .
JOURNAL OF CRYSTAL GROWTH, 1997, 178 (1-2) :201-206
[7]  
COULOMB P, 1957, DISLOCATIONS MECHANI, P555
[8]   Layer-by-layer growth of AlN and GaN by molecular beam epitaxy [J].
Daudin, B ;
Widmann, F .
JOURNAL OF CRYSTAL GROWTH, 1997, 182 (1-2) :1-5
[9]   The key role of polarity in the growth process of (0001) nitrides [J].
Daudin, B ;
Rouviere, JL ;
Arlery, M .
MATERIALS SCIENCE AND ENGINEERING B-SOLID STATE MATERIALS FOR ADVANCED TECHNOLOGY, 1997, 43 (1-3) :157-160
[10]   GROWTH-MORPHOLOGY OF VICINAL HILLOCKS ON THE (101) FACE OF KH2PO4 - FROM STEP-FLOW TO LAYER-BY-LAYER GROWTH [J].
DEYOREO, JJ ;
LAND, TA ;
DAIR, B .
PHYSICAL REVIEW LETTERS, 1994, 73 (06) :838-841