Low Temperature Activation of Mg-Doped GaN in O2 Ambient

In this study, Mg-doped GaN epitaxial layers were grown by metalorganic vapor phase epitaxy (MOVPE) and annealed in O2, air and N2. It was found that we could achieve a low-resistive p-type GaN by O2-ambient annealing at a temperature as low as 400°C. The resistivity and hole concentration of the 400°C O2-ambient annealed Mg-doped GaN was 2 Ω-cm and 3×1017 cm-3, respectively. These values are equivalent to those values obtained from Mg-doped GaN annealed in N2 ambient at 700°C.