THERMAL-STABILITY OF WSIN-GAAS AND AU-WSIN INTERFACES

The thermal stability of a Au/WSiN/GaAs system is studied. Current-voltage characteristics of Schottky diodes and depth profiles measured by secondary ion mass spectrometry and Auger electron spectroscopy indicate that both WSiN-GaAs and Au-WSiN interfaces are stable up to at least 800°C. The radial distribution functions for WSiN films determined by extended X-ray absorption fine structure of tungsten L3 edge suggest that nitrogen atoms are located at the interstitial-like sites of the amorphous W-Si network. It is clarified that WSiN films effectively suppress the diffusion of Ga, As, and Au atoms because an amorphous structure free from grain boundaries is maintained even after annealing at 800°C, and nitrogen atoms plug up the interstitial-like sites. © 1989.