Detection of Titanium Silicide Formation and Phase Transformation by Picosecond Ultrasonics

Abstract

Picosecond ultrasonics is employed to study the titanium silicide formation sequence for evaporated Ti films on silicon substrates annealed at temperatures between 300 and 800 °C. The measurements show significant differences in the ultrasonic echo pattern before and after the structural phases C49 and C54 are formed, thus indicating that picosecond ultrasonics is a sensitive non-destructive probe of silicide formation. The longitudinal sound velocity has been found to be (8.3 ± 0.2) × 10 5 cm/sec for C49 TiSi 2 , and about 5% lower for the C54 phase.