INCREASED THERMAL-STABILITY OF AU/GAAS METAL-INSULATOR-SEMICONDUCTOR SCHOTTKY DIODES WITH SILICON-NITRIDE INTERFACIAL LAYER DEPOSITED BY REMOTE PLASMA-ENHANCED CHEMICAL-VAPOR DEPOSITION

The effect of the ultrathin interfacial layer of silicon nitride deposited by remote plasma-enhanced chemical vapor deposition technique on the Schottky barrier characteristics of Au/n-GaAs contacts is investigated. The changes of both capacitance-voltage and current-voltage characteristics, in dependence on the interfacial layer thicknesses are discussed and explained on the basis of the surface passivation. The influence of thermal annealing on the structure and electrical properties is also presented. In contrast to the very poor stability of the electrical characteristics of reference Au/GaAs contacts, structures with silicon nitride interfacial layers show much improved thermal stability with the minimum ideality factor for the silicon nitride interfacial layer being 9 angstrom thick and annealed at 450-degrees-C. The effect of silicon nitride interlayer as a diffusion barrier is confirmed by Auger electron spectroscopy analysis of both reference and silicon nitride containing structures.