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

This work performs Si ion implantation the electrical conductive type of the p-GaN film from p-type to n-type. Multiple implantation method is also used 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. The implant dose is 5×10¹⁵ cm^-2 for each implant energy. After implantation, the samples are annealed in a N₂ ambient for different annealing temperatures and annealing times. The activation efficiency reaches as high as 20% when annealing the sample at 1000 °C. The carrier activation energy is about 720 meV. The low activation energy indicates that the hopping 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.