Substrate misorientation dependence of the hexagonal phase inclusion in cubic GaN films grown by metalorganic vapor phase epitaxy

The metalorganic vapor phase epitaxial (MOVPE) growth of cubic GaN layers o n misoriented GaAs (001) substrates, the faces of which were tilted from (0 01) toward [1 (1) over bar 0] or [110] by 4 degrees, was performed in order to investigate the effect of the substrate misorientation on the inclusion of hexagonal phase in the cubic GaN layer. The sample grown on the tilted surface toward [1 (1) over bar 0] showed an enhanced generation of the hexa gonal domain on the (1 (1) over bar 1) face, whereas the hexagonal domain o n the ((1) over bar 11) face was suppressed. The sample grown on the tilted surface toward [110] showed the generation of the hexagonal domains on bot h the (1 (1) over bar 1) and ((1) over bar 11) faces with an equal magnitud e, it is suggested that the generation of hexagonal domains may be suppress ed when the exposure of the (1 (1) over bar 1) or ((1) over bar 11) faces b y the thermal damage of the substrate surface is reduced.