Phase Transition and Formatio of $TiSi_2$ Codeposited on Atomicaily Clean Si(111)

The phase transition and the surface and interface morphologies of formed on atomically clean Si substrates are investigated. 200 Ti and 400 Si films on Si(ll1) have been codeposited at elevated temperatures (400~) in ultrahigh vacuum. The phase transition of TiSiL is characterized with using XRD. The results distinguish the formation of the C49 and C54 crystalline titanium silicides. The surface and interface morphologies of titanium silicides have been examined with SEM and TEM. A relatively smootb surface is observed for the C49 phase while a rough surface and interface are observed for C54 phase. The islanding of the C54 phase becomes severe at high temperature (). Islands of TiSiL have been observed at temperatures above but no islands are observed at temperatures below . For films deposited at and 500%. weak XRD peaks corresponding to TiSi were observed and TEM micrographs exhibited small crystalline regions of titanium silicide at the interface.