Selective layers of TiSi2 deposited without substrate consumption in a cold wall LPCVD reactor

Abstract Selectively deposited layers of TiSi2 have been obtained without silicon substrate consumption using the TiCl4/SiH4 system diluted in H2. For a given set of parameters, at 800°C, we show that TiSi2 formation uses Si from the substrate or from the gas phase. The important parameters are the reacting gas ratio, carrier gas nature and process time. We present some possible mechanisms which include surface reactions as well as mass-transfer as the limiting phenomena. We propose a model, involving gas mass transport of TiCl4 as the rate limiting step and assuming independence of the SiH4 chemistry, which agrees well with the experimental results.