Influence On The Inclusion Of H-Gan Domain Of The Mosaicity In C-Gan Epilayer Grown On (001) Gaas Substrate By Rf-Mbe

Inclusion of hexagonal GaN (h-GaN) phase domain associated with the mosaicity of the cubic GaN (c-GaN) phase have been investigated for c-GaN epilayer grown on (001) GaAs by rf-MBE. In the c-GaN epilayer with 10 % h-GaN phase, two diffraction peaks near (002) c-GaN were observed in the X-ray reciprocal space Mapping. One is the strong and narrow peak arising from the pure c-GaN phase and the other is the weak and broad peak arising from the secondary c-GaN phase with mosaicity. The broad peak showed its peak shift from the calculated diffraction angle, i.e., the tilt of c-GaN [001] axis is attributed to the secondary phase c-GaN domain. The diffraction peak for (10-11) h-GaN also showed its peak shift from the calculated diffraction angle. Therefore, it is considered that the h-GaN phase domain was preferentially included in the secondary phase c-GaN domain.