Study of Ti/W/Cu, Ti/Co/Cu, and Ti/Mo/Cu multilayer structures as Schottky metals for GaAs diodes

Abstract

Schottky structures with copper and refractory metals as diffusion barrier for GaAs Schottky diodes were evaluated. These structures have lower series resistances than the conventionally used Ti/Pt/Au structure. Based on the electrical and material characteristics, the Ti/W/Cu and Ti/Mo/Cu Schottky structures are thermally stable up to 400degreesC; the Ti/Co/Cu Schottky structure is thermally stable up to 300degreesC. Overall, the copper-metallized Schottky structures have excellent electrical characteristics and thermal stability, and can be used as the Schottky metals for GaAs devices.