Detailed in-situ monitoring of film growth: application to TiSi 2 chemical vapor deposition

Abstract

An experimental approach for monitoring chemical vapor deposition is described that combines in-situ, real-time monitoring of deposition rate and gas composition together with transfer capabilities into ultrahigh vacuum for Auger analysis. This approach has been applied in the specific case of TiSi 2 low-pressure deposition on Si using TiCl 4 and SiH 4. In the early stages of growth, Si for the growing film is supplied directly from the substrate. In later stages, Si arrives through SiH 4 adsorption. The primary gas phase reaction products are H 2, HCl, SiH 3Cl and the radical species SiCl 2. Removing surface contamination from the substrate is not sufficient to promote film nucleation; surface defects are apparently required as well. Steady-state multiplicity in the reaction rate is observed near 700°C for large SiH 4:TiCl 4 ratios.