Thermal stability of Ti/Pt/Cu Schottky contact on InAlAs layer

Abstract

Electrical characteristics and thermal stability of the Ti/Pt/Cu Schottky contact on InAlAs were investigated. The Ti/Pt/Cu Schottky contact had comparable electrical properties compared to the conventional Ti/Pt/Au contact after annealing. As judged from the material analysis, the Ti/Pt/Cu on InAlAs after 350 degrees C annealing showed no diffusion sign into the InAlAs. After 400 degrees C annealing, the interfacial mixing of Cu and the underlying layers occurred and resulted in the formation of Cu4Ti. The results show that Ti/Pt/Cu Schottky contact using platinum as the diffusion barrier is very stable up to 350 degrees C annealing and can be used for InAlAs/InGaAs high-electron mobility transistors and monolithic microwave integrated circuits. (c) 2006 American Institute of Physics.