Open AccessTheoretical research on critical thickness of HgCdTe epitaxial layers
Author(s) -
Qingxue Wang,
Yang Jian-Rong,
Wei Yan-Feng
Publication year - 2005
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.54.5814
Subject(s) - epitaxy , materials science , substrate (aquarium) , composition (language) , molecular beam epitaxy , dislocation , strain (injury) , thin film , optics , crystallography , composite material , nanotechnology , chemistry , geology , layer (electronics) , physics , medicine , linguistics , oceanography , philosophy
Based on the relationships between stress and strain in an arbitrary coordinate system, the elastic theory of crystal and the dislocation gliding theory, the critical thicknesses of HgCdTe/CdZnTe oriented in the 111 and 211 directions are calculated, and the dependence of the critical thickness of HgCdTe on substrate composition and film composition are studied. The results show that the critical thickness of HgCdTe depends sensitively on substrate composition and film composition. For 10μm films oriented in the 111 direction prepared by liquid phase epitaxy, the substrate composition and the films composition must match to within ±0.225‰ and ±5‰, respectively, to prevent the occurence of misfit dislocations. In addition, for 10μm films oriented in the 211 direction prepared by molecular beam epitaxy, the actual ranges of zinc composition and the films composition are ±0.2‰ and ±4‰ for the films to remain below the critical thickness, respectively.