Thermal Stability of Implanted or Plasma Exposed Deuterium in Single Crystal Ga2O3

The thermal stability and migration of both ion implanted (100 keV, 10(15) cm(-2)) or plasma diffused (100-270 degrees C for 0.5h) H-2 in single-crystal beta-Ga2O3 was examined as a function of post-implantation annealing temperature (450-650 degrees C for the implanted samples, 400-500 degrees C for the plasma diffused samples) by Secondary Ion Mass Spectrometry. In the as-implanted condition, the profiles show a peak deuterium concentration of similar to 3.1 x 10(19) cm(-3) at a depth of similar to 0.85 mu m for our dose and energy conditions. Subsequent annealing causes outdiffusion of H-2 from the Ga2O3 with the remaining deuterium migrating toward the surface and decorating the residual implant damage. After annealing at 650 degrees C, only 12% of the original dose is retained within the Ga2O3. This loss of deuterium in the implanted samples was modelled with using the FLOOPS code, and showed good agreement with experiment and an activation energy of 1.35 eV for the rate constant. The plasma treated samples showed deuterium incorporated to a depth of similar to 0.67 mu m for plasma exposure at 270 degrees C, corresponding to an estimated deuterium diffusivity of 6.4 x 10(-13) cm(2)/V.s at this temperature. (C) 2016 The Electrochemical Society. All rights reserved.