Interfacial reactions of W thin film on single-crystal (001) β-SiC

Interfacial reactions between a W thin film and a single-crystal (001) β-SiC substrate on rapid thermal annealing from 600 °C to 1100 °C for 60 s were investigated by backscattering spectrometry, X-ray diffraction, secondary ion mass spectrometry and cross-sectional transmission electron microscopy. Backscattering spectrometry shows that W reacts with SiC at 950 °C. The product phases identified by X-ray diffraction are W₅Si₃ and W₂C. At 1100 °C no more unreacted W is detected. Current-voltage measurements show that ohmic contacts are already obtained on as-deposited W. Contact resistivity measured using the circular transmission line model is about 10^-3 Ω cm². Thermodynamic studies of the solid phase stability in the ternary WSiC system help us to understand the chemical stability of W thin film.