Depth‐Resolved Photoluminescence for Channeling Implantation of Mg or Mg/N Ions into GaN after Ultra‐High‐Pressure Annealing

p‐type doping profiles designed for a junction termination extension (JTE) in vertical GaN power devices fabricated by channeling ion implantation (I/I) of Mg or Mg/N ions into GaN and subsequent ultra‐high‐pressure annealing at 1300 °C are analyzed by depth‐resolved photoluminescence (PL) spectroscopy. PL spectra are acquired after low‐damage dry etching to different depths. The activated Mg acceptor concentration is quantified at each depth from the calibration curve using the PL intensity ratio between acceptor‐bound excitons (A 0 X A ) and free excitons (FX A ). Residual nonradiative recombination centers (NRCs) are also discussed on the basis of the PL intensity profiles. Most of the implanted Mg ions are substituted into Ga sites in both cases of Mg‐I/I and Mg/N‐I/I. By contrast, the concentration of residual NRCs near the mean implantation depth is substantially reduced in the Mg/N‐I/I case. The rapid substitution of Mg ions into Ga sites and the enhanced I/I defect recovery by sequential N‐I/I observed in the channeling I/I case are similar to those observed in the random I/I case reported previously. It is concluded that channeling Mg/N‐I/I is a suitable process for fabricating JTEs with deep p‐type profiles containing low I/I defect concentrations.