Interaction of reactively sputtered titanium carbide thin films with Si, SiO2Ti, TiSi2, and Al

Abstract

The interactions of reactively sputtered titanium carbide (Ti_xC) films with Si, SiO₂, Ti, TiSi₂, and Al have been studied using Auger electron spectroscopy, x‐ray diffraction, and four‐point probe resistance. The Ti_xC films react with Si leading to silicide phases that are not observed when pure Ti reacts with Si. The interaction of Ti_xC with Si is delayed to higher temperatures with increasing carbon content. For x≤1, no interaction is observed even after 900 °C‐30 min anneal. For x≥1, the silicide formation leads to phase separation with TiSi₂ near the silicon substrate plus an outer titanium carbide layer, which, like all other Ti_xC films investigated, is found to be an effective diffusion barrier to Al penetration up to 500 °C. For x≤1, no interaction with SiO₂ is observed up to 900 °C. However, Ti‐rich films interact with SiO₂ to form titanium oxide. The stoichiometric film adheres to Ti and TiSi₂ much better than to Si and SiO₂. It does not react with Ti or TiSi₂ up to 750 °C. At 900 °C TiC is unstable on TiSi₂.