Atomic Force Microscopy Investigation of Tensile-Stressed Silicon Grown by Rapid Thermal Chemical Vapour Deposition on Si_<0.68>Ge_<0.32> Relaxed Pseudo-substrates

概要

論文の詳細を見る
Rapid thermal chemical vapour deposition (RTCVD) has been applied to the growth of silicon layers under tensile stress on relaxed Si_<0.68>Ge_<0.32> buffer layers at 610 and 81O℃. Their sturface morphology was characterised withatomic height resolution by Tapping-mode atomic force microscopy (TV-AFM). While a uniform isotropicnanoroughness is revealed on pseudo-substrates, a quite different roughness can be observed for silicon films. For high temperature grown films, high surface diffusion rates of adsorbed species enable an extended reconstructionof the Si (1OO) surface : large domains showing terraces as well as faceted planes appear ; the resulting non-uniformsilicon film exhibits early mechanical failure. In contrast, low temperature grown Si films exhibit almost the same morphology as pseudo-substrates for thicknesses up to 15 nm with no apparent mechanical failure. For thicknesses beyond 20 nm, terraces form on the steepest part of the slopes, whereas beyond 80 nm<110>slip lines indicate the plastic yield of the film.
社団法人応用物理学会の論文
1994-12-15