Ti/Al and Cr/Al Ohmic Contacts to n-Type GaN Formed by Furnace Annealing

High-quality, low-resistance ohmic contacts are critical for the development of GaN devices for high-temperature applications. Ti /Al metallization has been previously shown to form ohmic contacts to n-type GaN after 900 C rapid thermal annealing (RTA). In this work we report on the investigation of the Ti/Al system for ohmic contacts to n-GaN by using the conventional quartz furnace annealing method. Low-resistivity ohmic contacts were achieved with this method at considerably lower temperatures (as low as 550 C) than those required by RTA. We report on a new contact system consisting of Cr/Al metallization that also quartz furnace annealing. (Author)