Thermal Conductivity and Interface Thermal Conductance of Titanium Silicide Films on Si

Abstract

Titanium silicide films were prepared by magnetron sputtering of Ti on B-doped Si (100) and annealing at different temperatures up to 700 °C in argon atmosphere. Films were also prepared by laser physical vapor deposition (LPVD) of Ti at 500 °C and 600 °C on B-doped Si (100) followed by in situ annealing. The films were characterized by X-ray diffraction for phase identification, scanning electron microscopy for interface microstructure and oxygen level, atomic force microscopy for interface roughness, transient thermoreflectance for thermal conductivity and interface thermal conductance of the interface with Si. Annealing at 700 °C for 1 h was responsible for the complete formation of C54 phase. LPVD at 500 °C and 600 °C was responsible for C54 formation with smaller grain size, but unreacted Ti and other silicide phases were also present. The interface in all the films was continuous with the absence of voids. The thermal conductivity of the films increased for higher processing temperature. The interface thermal conductance for films prepared below 700 °C was lower. Film annealed at 700 °C significantly showed higher interface thermal conductance and lower effective thermal resistance. Comparison of thermal properties of the TiSi2 films with that of WSi2 films prepared previously showed that the effective thermal resistance of the C54 phase is lower.