Study of High Temperature Reaction between Ti and SiO₂ at Interface in Ti/SiO₂/TiSi₂/Si System by XPS

Abstract

High temperature reaction between Ti and SiO₂ at interface in Ti/SiO₂/TiSi₂/Si system is studied using X-ray photoelectron spectroscopy (XPS) in conjuction with argon-ion sputtering. Below 750°C, the Ti_xSi_y (x/y=1.0-1.2) is formed, and the thickness of SiO₂ layer is thin. Above 750°C, the TiSi₂ is formed, and relative atomic concentration of Si in SiO₂ (Si-ox) is sharply decreased. To compare the experimental results of Ti/SiO₂/TiSi₂/Si system with that of Ti/ SiO₂/Si system, one found that the formation of additional TiSi₂ film will mainly be controlled by the substrate silicon atoms which diffuse to the surface layer through the grain boundary in the layer of TiSi₂ and SiO₂.