An Optimization Study of Thermal Stability of W/GaAs Schottky Gates

Abstract

ABSTRACTThis paper presents an experimental study of the physical and electrical characteristics of tungsten (W) thin films versus the deposition parameters of sputtering. A correlation between the W film characteristics and thermal stability of the W/GaAs Schottky diodes is also presented. Good thermal stability was obtained for W gates with low resistivity and α-W phase, deposited at low pressure and low RF power. W films deposited at high pressure presented high resistivity, β-W phase and weak thermal stability. Diodes annealed under As over-pressure ambient presented an enhanced thermal stability of about 100°C.