Characteristics of Mg-Doped GaN and AlGaN Grown by H2-Ambient and N2-Ambient Metalorganic Chemical Vapor Deposition

The characteristics of Mg-doped GaN and AlGaN grown by H 2 -ambient and N 2 -ambient metalorganic chemical vapor deposition are compared and discussed. While as-grown Mg-doped GaN and AlGaN grown under H 2 -ambient show high resistivity, p -type GaN and AlGaN with high acceptor concentration were obtained by N 2 -ambient growth without any post-treatment. The hydrogenation process of the Mg acceptor and the dissociation process of hydrogen atoms from Mg–H complexes might occur simultaneously in the case of N 2 -ambient growth. The films grown under N 2 -ambient were clearly shown to have superior characteristics in uniformity and reproducibility to those grown under H 2 -ambient, since the characteristics of the films grown under N 2 -ambient are steady over the wide range of growth temperature. Our results indicate that the N 2 -ambient growth is suitable for the mass production of GaN-based light-emitting devices in the respects that the device fabrication process can be simplified and that the uniformity and the reproducibility of the layer properties are greatly improved.