Electrical properties of Cobalt contact to p-GaN

Abstract

The effects of rapid thermal annealing (RTA) on Co/p-GaN contacts in an O2/N2 atmosphere without intermediate metal were investigated. It was observed that the contact resistance decreased with increasing RTA temperature and that the resistance was reduced by a factor of about 30 after RTA at 600 ℃ in the O2/N2 atmosphere. The specific minimum contact resistance was about 10-²

Ω·cm² range. Comparison of the R0 and ρc values revealed that the rapid thermal annealing in the O2/N2 was more effective for reducing the contact resistance than the normal 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 O2/N2 atmosphere.