Effects of rapid thermal annealing on the electrical properties of cobalt contact to p-GaN

Abstract

The effects of rapid thermal annealing (RTA) on Co/p-GaN contacts in an O-2/N-2 atmosphere without intermediate metal were investigated. It was observed that the contact resistance (rho (c)) decreased with increasing RTA temperature and that the resistance was reduced by a factor of about 30 after RTA at 600 degreesC in the O-2/N-2 atmosphere. The specific minimum contact resistance was in the 10(-2) Omega .cm(2) range. Comparison of the R-0 and rho (c) values revealed that the rapid thermal annealing in the O-2/N-2 was more effective for reducing the contact resistance than conventional furnace annealing, The reason for the reduction of resistance was expected to be the increase of hole concentration due to the highly reactivated removal of hydrogen atoms in the p-GaN by RTA in the O-2/N-2 atmosphere.