Measurement of temperature-dependent defect diffusion in proton-irradiated GaN(Mg, H)

摘要

Deuterated p-type GaN(Mg,~2H) films were irradiated at room temperature with 1 MeV protons to create native point defects with a concentration approximately equal to the Mg doping (5 X 10~(19) cm~(-3)). The samples were then annealed isothermally at a succession of temperatures while monitoring the infrared absorption due to the H local mode of the MgH defect. As the samples were annealed, the MgH absorption signal decreased and a new mode at slightly higher frequency appeared, which has been associated with the approach of a mobile nitrogen interstitial. We used the time dependence of the MgH absorption to obtain a diffusion barrier of the nitrogen interstitial in p-type GaN of 1.99 eV. This is in good agreement with theoretical calculations of nitrogen interstitial motion in GaN.