Amorphous Metallizations for High-Temperature Semiconductor Device Applications

In this paper we present the initial results of work on a new class of semiconductor metallizations which appear to hold great promise as primary metallizations and diffusion barriers for high-temperature device applications. These metallizations consist of sputter-deposited films of high-Tg amorphous-metal alloys which (primarily because of the absence of grain boundaries) exhibit exceptionally good corrosion resistance and low diffusion coefficients. Amorphous films of the alloys Ni-Nb, Ni-Mo, W-Si, and Mo-Si have been deposited on Si, GaAs, GaP, and various insulating substrated. The films adhere extremely well to the substrates and remain amorphous during thermal cycling to at least 500°C. Rutherford Backscattering (RBS) and Auger Electron Spectroscopy (AES) measurements indicate atomic diffusivities in the 10-19 cm2/S range at 450°C.