Abstract
Using Schottky barrier measurements on n−GaAs diodes metallized with Au/W and Pt/W films, we have shown that thin films of W (∼3000 Å) offer an excellent barrier to diffusion of both Au and Pt atoms at temperatures up to 500 °C. These properties of W are utilized in a Schottky barriermetallization scheme consisting of Au/W/(PtGa/PtAs2)/n−GaAs, where (a) the thin sintered Pt layer provides a large φ B (due to PtAs2 at the GaAs interface) and a metallurgically stable conductor−semiconductor interface, (b) the W layer acts as a diffusion barrier, and (c) the outer Au layer provides thermocompression bondability.