Electrical properties of multiple high-dose Si implantation in p-GaN

This work performs Si ion implantation the electrical conductive type of th e p-GaN film from p-type to n-type. Multiple implantation method is also us ed to form a uniform Si implanted region in the p-type GaN epitaxial layer. Implant energies for the multiple implantation are 40, 100, and 200 KeV. T he implant dose is 5 x 10(15) cm(-2) for each implant energy. After implant ation, the samples are annealed in a N-2 ambient for different annealing te mperatures and annealing times. The activation efficiency reaches as high a s 20% when annealing the sample at 1000 degrees C. The carrier activation e nergy is about 720 meV. The low activation energy indicates that the hoppin g process mechanism is the dominant mechanism for the activation of the Si implantation in p-GaN. Moreover, the rectifying I-V characteristic of the p -n GaN diode is also examined.