Nanostructural Silicon Films Prepared by Metal-Induced Growth Using an RTCVD System

Abstract

Nanostructural (grain size of 35–80 nm) silicon films had been prepared by a metal-induced growth (MIG) technique with a rapid thermal chemical vapor deposition (RTCVD) system. A low-temperature (550°C) RTCVD process was presented to deposit these nanostructural silicon films onto a Ni-prelayer substrate. The influences of various thickness of Ni prelayer, hydrogen flow rate, and growth temperatures on the nanostructural silicon films were investigated in this study. It is shown that thicker Ni films (≧15 nm) could result in uniform nanograin silicon films, while for the thinner ones (≦10 nm), larger whisker crystals and some nanocrystalline grains were found distributed randomly on a smooth amorphous film. More flow rate retards the formation of compound and thus offers nanocrystalline silicon films. The lower growth temperature (≦500°C) has the same results. All these examinations were demonstrated by X-ray diffraction, scanning electron microscopy, Raman spectra, and atomic force microscopy analysis. The mechanism of MIG by the RTCVD system was explained from a result of Auger depth profiles. © 2004 The Electrochemical Society. All rights reserved.