Epitaxial growth of Si on SiH3CH3 reacted Ge(1 0 0) using ultraclean hot-wall low-pressure chemical vapor deposition (LPCVD), and the intermixing between Si and Ge during heat treatment has been investigated. By SiH3CH3 reaction at 450 degreesC, Si and C atomic layers are self-limitedly formed on Ge(1 0 0), and the number of C atoms decreases with increasing heat treatment temperature in the range of 500-700 degreesC. After such treatment, Si epitaxial growth on the 6 x 10(13) cm(-2) C existing Ge(1 0 0) is achieved at 500 degreesC. To clarify the interface abruptness, dependence of Ge-3d intensity on the depth are obtained by repetition of X-ray photoelectron spectroscopy (XPS) measurements and wet etching. It is found that the intermixing between Si and Ge during Si epitaxial growth and heat treatment after its growth is suppressed by the existence of C atoms at the heterointerface. (C) 2003 Elsevier Science B.V. All rights reserved.