ABSTRACT
Cubic GaN can be grown under some growth conditions, although the crystal structure of the stable phase of GaN is hexagonal. Cubic Ill-nitride materials on GaAs substrates are being developed for use in light emitting devices because of the easy cleavability of this materials and the good conductivity of the substrate. We have reported optically pumped stimulated emission from a cubic GaN/AlGaN heterostructure[l] and a p-n junction diode fabricated from cubic GaN[2]. To improve the crystal quality of epitaxial films, a common method is to increase the growth thickness; however, the film thicknesses reported in these papers were less than 2 pm. This is because the hexagonal phase in cubic GaN tends to increase with increasing growth thickness. In this paper, we report successful growth of thick cubic GaN by a three-step growth process.
