INTERFACIAL REACTIONS OF W THIN-FILM ON SINGLE-CRYSTAL (001)BETA-SIC

Interfacial reactions between a W thin film and a single-crystal (001) beta-SiC substrate on rapid thermal annealing a from 600 degrees C to 1100 degrees C for 60 a were investigated by backscattering,o spectro metry, X-ray diffraction, secondary ion mass spectrometry and cross-se ctional transmission electron microscopy. Backscattering spectrometry shows that W reacts with SiC at 950 degrees C. The product phases iden tified by X-ray diffraction are W5Si3 and W2C. At 1100 degrees C no mo re unreacted W is detected. Current-voltage measurements show that ohm ic contacts are already obtained on as-deposited W. Contact resistivit y measured using the circular transmission line model is about 10(-3) Ohm cm(2). Thermodynamic studies of the solid phase stability in the t ernary W-Si-C system help us to understand the chemical stability of W thin film.