Electron-beam dissociation of the MgH complex in <i>p</i>-type GaN

Abstract

The dissociation of the MgH complex in GaN under low-energy electron-beam irradiation (LEEBI) and its reassociation during postirradiation annealing were measured using infrared vibration spectroscopy. The dissociation rate exhibits a pronounced dependence on the H isotope, being about 4 times greater for protium than deuterium. Reassociation occurs at temperatures &amp;lt;200 °C, which may be problematic for device applications of LEEBI. We consider possible reaction paths based on atomic configurations from density-functional theory and bond-excitation mechanisms investigated in surface-desorption studies, thereby arriving at a model of the evolution consistent with the experimental results.