High-temperature stability of Nb/GaAs and NbN/GaAs interfaces

Abstract
The interface stabilities of Nb/GaAs and NbN/GaAs contacts at temperatures up to 700 °C for Nb/GaAs and 850 °C for NbN/GaAs have been investigated by transmission electron microscopy and x-ray diffractometry techniques. Results reveal that a Nb/GaAs reaction takes place at temperatures above 600 °C, and interdiffusion at the NbN/GaAs interface occurs at temperatures above 800 °C. The correlation between the observed interface morphologies before and after annealing and previously reported electrical properties of these contacts is also discussed.