Cobalt silicide formation has been shown to be improved by a reactive Ti capping layer. We investigated the effects of the first rapid thermal anneal (RTA1) temperature on the silicidation mechanism and COSi2 film properties. It was found that a higher RTA1 temperature results in lower sheet resistance, a smoother COSi2/Si interface and better film thermal stability. The improved thermal stability may be explained by the smoother COSi2/Si interface at higher RTA1 temperature. (C) 2003 Elsevier Science Ltd. All rights reserved.