Properties of Zn implanted GaN

We report the optical and structural properties of ion implanted GaN. Post-implant annealing up to 1100°C was performed under flowing N2 in both a tube furnace and a rapid thermal annealing (RTA) system, with and without SiNx encapsulation layers. The implantation damage is quantified by transmission electron microscopy (TEM). Secondary ion mass spectroscopy (SIMS) detects significant rearrangement of implanted Zn only at the highest temperatures and doses investigated. Strain reduction, observed in GaN annealed at or above 975°C by high-resolution x-ray diffractometry (HRXRD), indicates successful damage removal. The optical activation of annealed GaN is measured by photoluminescence (PL). The room temperature (RT) Zn acceptor transition at approx.430 nm is consistently observed in annealed GaN, but at low efficiency. We conclude that residual implantation damage and/or N loss during annealing limits the optical quality of implanted GaN.