Low-temperature activation of Mg-doped GaN using Ni films

The activation of metalorganic chemical vapor deposition-grown Mg-doped GaN by N2 annealing with a thin Ni film has been investigated. p-type conduction in GaN has been obtained at an annealing temperature as low as 200 °C using the proposed technique. A hole concentration of 2×1017 cm−3 has been achieved by the annealing at 400 °C. Secondary ion mass spectroscopy measurements have revealed that hydrogen is effectively removed from the Mg-doped GaN layer. These results suggest that the Ni film significantly enhances hydrogen desorption from the GaN film, which results in the activation of Mg-doped GaN at quite low temperatures.