Method of manufacturing a semiconductor device

Abstract

While conventionally, a Co film is deposited by directional sputtering directly on a source/drain diffusion layer formed on the surface of an Si substrate while the substrate is being heated, a thin oxide film is formed on the source/drain diffusion layer and then, the Co film is deposited by directional sputtering while the substrate is being heated. By doing this, an inner Co—Si layer the composition of which is thermally unstable is formed and a Co—Si—O layer is formed on the Co—Si layer. After the remaining unreacted Co film and the Co—Si—O layer are selectively removed, a high-temperature heat treatment is performed, so that the inner Co—Si layer is transformed into a CoSi layer to increase the film thickness. The formation of the oxide film curbs the speed of reaction between Co and Si, so that a Co—Si layer of the same thickness as that in the wide region can be formed in the fine region. As a result, a CoSi layer with uniform thickness and sheet resistance can be formed.