화학공학소재연구정보센터
Journal of Crystal Growth, Vol.283, No.1-2, 57-67, 2005
Growth of SiGe/Si superlattices on silicon-on-insulator substrates for multi-bridge channel field effect transistors
We have studied in reduced pressure chemical vapor deposition the growth kinetics of Si and Si0.8Ge0.2 on bulk Si(0 0 1) and on silicon-cm-insulator (Sol) (100 nm buried oxide/20 nm Si over-layer) substrates. For this, we have grown miscellaneous Si/Si0.8Ge0.2 superlattices on both types of substrates that we have studied mainly in secondary ions mass spectrometry but also in X-ray diffraction. Systematic Si and SiGe growth rate decreases (together with a Ge concentration increase) occurred on Sol substrates as the stack thickness increased from zero to more than 100 nm. Such phenomena are most likely associated to a decrease of the Sol surface temperature by 12-13 degrees C compared to bulk. For Si, the growth rate on Sol increased back again towards the bulk value as the stack thickness neared two hundred nanometers. This is linked to a Sol surface temperature that went 5 degrees C back up. Such a knowledge will be most useful to form in the near future regular superlattices on Sol substrates that will serve as the active regions of multi-bridge channel field effect transistors. Three periods Si/SiGe superlattices with either 20% or 31 % of Ge and varying SiGe layer thickness were also grown on bulk Si(0 0 1) to study the critical thickness for plastic relaxation of the compressive strain that builds up in such stacks. (c) 2005 Elsevier B.V. All rights reserved..