The influence of silicon substrate crystallinity and doping on TiSi₂ thin film morphology

Abstract

TiSi2 was formed on amorphous, polycrystalline or single crystal silicon. Undoped samples are compared with specimens where the silicon had been doped with phosphorus or arsenic prior to titanium deposition. A non-destructive optical technique, total intergrated scattering (TIS) was used together with more conventional methods to evaluate the surface conditions after various treatments. These analyses were correlated with Rutherford backscattering spectrometry (RBS) to obtain more comprehensive information on the bulk morphologies. The dopant species play an important role for the morphology and stability of these structures. It is shown that TiSi2 on undoped polysilicon is unstable at temperatures above 800°C and that an amorphous substrate offers potential advantages such as a smoother and more stable silicide. © 1993.