Chemical vapor deposition of silicon carbide titanium carbide composite films from dichlorodimethylsilane, titanium tetrachloride, and methane

Composite films of silicon carbide (SiC) and titanium carbide (TiC) were prepared from mixtures of dichlorodimethylsilane (DDS), titanium tetrachloride (TiCl4), and methane (CH4) at 1273 K by atmospheric-pressure chemical vapor deposition (APCVD), The addition of DDS significantly increased TiC deposition at a temperature where insignificant deposition of TiC Occurred from TiCl4 and CH4 in the absence of DDS. The composition of the composite films strongly depended on the feed ratio of DDS to TiCl4. SiC/TiC composites formed for DDS/TiCl4 > 1.5, and pure TiC formed for DDS/TiCl4 < 1. A reaction model was developed where gas-phase reactions and decomposition of DDS form highly reactive CH3-SiCl2 and CH3 that react with TiCl4 to form TiCl3 and/or TiCl2. The combination of DDS, TiCl4, and CH4 is a promising precursor system for SiC/TiC chemical vapor deposition to form either composites or pure TiC. (C) 1999 The Electrochemical Society, S0013-4651(98)03-100-0. All rights reserved.