Mineo Okuyama

Catalytic effect of Ni for activation of Mg-doped GaN in N2 and N2O

Abstract Catalytic effect of Ni for activation of metalorganic chemical vapor deposition-grown Mg-doped GaN in N2 and N2O has been investigated. P-type GaN has been obtained at an annealing temperature as low as 200°C using the Ni catalytic film in N2O as well as in N2. Moreover, the hole concentrations for the samples obtained by annealing in N2O were in good agreement with those obtained in N2 in the whole annealing temperature range. These results indicate that the Ni film effectively acts as a catalyst to enhance hydrogen desorption at the surface of GaN, which results in the reduction of hydrogen concentration in GaN at low annealing temperatures. It has also been suggested that the catalytic activity of Ni to enhance hydrogen desorption is much stronger than that of N2O. Therefore, an introduction of oxygen in the annealing atmosphere is not necessary for effective removal of hydrogen under the existence of the Ni film.

Low‐Temperature Activation of Mg‐Doped GaN with Pd Thin Films

The activation of metalorganic chemical vapor deposition (MOCVD)-grown Mg-doped GaN by N 2 annealing with thin Pd films has been investigated, p-type GaN with a hole concentration of 7 x 10 16 cm -3 has been obtained at an annealing temperature as low as 200 °C using this technique. Thermal desorption spectroscopy (TDS) measurements have revealed that hydrogen is effectively removed from the Mg-doped GaN layer by the use of the Pd film.