Effects of Long-Term Low-Temperature Annealing on Lightly Mg-Implanted GaN

The excellent properties of GaN are suitable for high-efficiency high-power devices. Especially, excellent high-power GaN MOSFETs are expected to be realized. For this purpose, the ion implantation technology should be established. However, formation of p-type GaN (p-GaN) by ion implantation is still challenging. Recently, Mg-ion implantation has been reported to form p-GaN [1 –5]. Still, post-implantation annealing at a very high temperature is necessary for achieving a high activation rate. By investigating the annealing behavior of defect states electrically, a clue to lower the annealing temperature for activating Mg acceptors might be found. However, a heavy implantation results in a high resistance of GaN layer, which makes the electrical measurements difficult. We investigated the effects of low-temperature annealing on the behavior of defects in lightly Mg-implanted GaN.