Patterned growth of (AlGa)As using metalorganic vapor-phase epitaxy

Citation
L. Hofmann et al., Patterned growth of (AlGa)As using metalorganic vapor-phase epitaxy, J CRYST GR, 206(4), 1999, pp. 255-262
Citations number
20
Categorie Soggetti
Physical Chemistry/Chemical Physics
Journal title
JOURNAL OF CRYSTAL GROWTH
ISSN journal
00220248 → ACNP
Volume
206
Issue
4
Year of publication
1999
Pages
255 - 262
Database
ISI
SICI code
0022-0248(199911)206:4<255:PGO(UM>2.0.ZU;2-8
Abstract
The regrowth of(AlGa)As over substrates patterned in [011] directions is an important step in the fabrication of index-guided laser structures. We pre sent a detailed study of the influences of growth parameters on the develop ment of the regrowth front and the composition profile. The overgrown (AlGa )As exhibits an inhomogeneous Al profile, strongly dependent on growth temp erature, with less Al on the {311}-sidewalls of the trenches than on planar facets. The ratio of the growth rate on the sidewalls to the planar growth rate is used to characterize the development of the growth front, and its dependence on reactor pressure, growth temperature and trench orientation i s studied. Differences in the growth behavior for the two trench orientatio ns are found with overgrowth on [0 (1) over bar 1] trenches being very sens itive to V/III ratio. This allows an estimation of the efficiency of the As precursors arsine (AsH3) and tertiary butyl arsine (TBAs) with TBAs being seven times more effective than AsH3 at 600 degrees C. The observed growth behavior is discussed in terms of group III mobilities, diffusion processes and bonding situations on the different surfaces. (C) 1999 Elsevier Scienc e B.V. All rights reserved.