[12a-M111-1~9] 15.7 Crystal characterization, impurities and crystal defects

▲ [12a-M111-9] Cathodoluminescence and 3D atom probe study of Mg implanted homoepitaxial GaN

〇JUN CHEN¹, Wei Yi¹, Jun Uzuhashi¹, Takashi Kimura¹, Shinya Takashima², Masahara Edo², Tadakatsu Ohkubo¹, Takashi Sekiguchi^1,3 (1.NIMS, 2.Fuji Electric, 3.Tsukuba Univ.)

Keywords:GaN, Dislocation, Mg

Mg ion implanted homoepitaxial GaN has been investigated by secondary ion mass spectrometry (SIMS), 3D atom probe, and cathodoluminescence (CL). Mg ion implantation was performed to form 1E19cm^-3 x 500 nm BOX profile. The implanted wafer was annealed at 1300°C for 5min with AlN protection layer, then AlN was chemically removed. CL can reveal the active Mg by donor-acceptor pair (DAP) emission. It suggests that: (1) there exist high concentration of nonradiative defects in the implanted region; (2) enhanced DAP emissions are detected from threading dislocations from substrate to epilayer. The Mg implantation layer is not luminescent due to the formation of Mg clusters as confirmed by 3D atom probe observation. To achieve successful Mg doping by ion implantation, it is necessary to avoid the formation of dead region in implanted layer and the diffusion of Mg along dislocations.