p -type activation of AlGaN by hydrogen desorption using catalytic Ni films

p -type activation of Mg-doped Al0.03Ga0.97N and Al0.08Ga0.92N by annealing process with Ni deposition has been investigated. Hole concentrations in both Al0.03Ga0.97N and Al0.08Ga0.92N by annealing at around 700°C with Ni were almost two times as high as those in samples annealed without Ni. Secondary ion mass spectroscopy has revealed that hydrogen concentrations in AlGaN annealed with Ni are lower than those without Ni. Thermal desorption spectroscopy showed drastic enhancement in hydrogen desorption at around 450°C from AlGaN films with Ni. We conclude that Ni deposition promotes the hydrogen desorption from AlGaN layers, resulting in effective p-type activation.