Low-damage, in-situ chemical etching of GaN by tertiarybutyl-chloride (TBCl)

In this study, we compared different process-treated surfaces by building Schottky diodes, and performing photoluminescence (PL) and Rutherfold backscattering (RBSc) measurements. TBCl etched sample has a leakage behavior approaches that of the as-grown sample under both forward and reverse biases, while dry-etched surface is very leaky. On the other hand, additional TBCl etching following dry etching could improve the leakage behavior. Same trends were also observed in both PL and RBSc measurements by comparing the near-band-edge emission and displaced atoms density on the surface, respectively. Both electrical and material characterizations confirm that TBCl etching is not only a low-damage etching method, but is also capable of removing damage induced by the dry etching process.