Ultrathin cobalt silicide film formation on Si(100)

The interfacial reaction between ultrathin Co film and substrate Si(100) was studied by in situ XPS using monochromatized Al Kalpha. When the Co is deposited on Si(100) at room temperature, CoSi2 is formed during the initial stage of Co deposition and then metallic Co starts to grow sequentially. For 8 ML Co deposition on Si(100) the interfacial reaction layer is relatively thin compared with the pure Co overlayer, which is not involved in the interfacial reaction in depth. The Co layers change rapidly to CoSi layers after annealing at 270 degreesC, and then CoSi2 layers form after annealing at 540 degreesC for 2 min. The CoSi2 layers are changed to CoSi2 islands by post-annealing at >650 degreesC. Copyright (C) 2003 John Wiley Sons, Ltd.