Effects of the sequential implantation of Mg and N ions into GaN for p-type doping
Hideki Sakurai, Tetsuo Narita, Keita Kataoka, Kazufumi Hirukawa, Kensuke Sumida, Shinji Yamada, Kacper Sierakowski, Masahiro Horita, Nobuyuki Ikarashi, Michał Boćkowski, Jun Suda, Tetsu Kachi
Abstract
The sequential implantation of Mg and N ions into GaN was investigated using conventional rapid thermal annealing and ultra-high-pressure annealing (UHPA). In cathodoluminescence, the green luminescence related to nitrogen vacancies (VNs) was mostly suppressed at the Mg/N ratio of 0.5–1.0, whereas the donor–acceptor pair (DAP) emission as a signature of Mg acceptors was maintained high. The excess N implantation reduced the DAP emission through the formation of nonradiative recombination centers. The combined process of optimal Mg/N implantation and UHPA at 1673 K improved ohmic contacts by increasing Mg concentration and suppressing VNs near the surface.