Metallurgical reactions in Au/(InGe) ohmic contacts to GaAs

The Au/(InGe) contact to GaAs was investigated to discover the metallurgical structure of the contact-GaAs interface. A variety of intermetallic phases in the form of precipitate particles or thin films were identified, and their presence was correlated with the temperature at which the contacts were fired. The possibility of predicting the structures of the fired contacts from simple metallurgical phase diagrams is discussed, and some evidence on the influence of the precipitating phases on the electrical character of the contacts is reviewed. © 1983.