Standard, semiconductor-industry bulk crystal growth processes are virtually impossible for the production of GaN as this is prohibited by both the high melt temperature of GaN and thermal decomposition of the compound into Ga metal and diatomic nitrogen gas. In this study, a novel hydrostatic pressure system was employed to grow GaN crystals in a very high pressure ambient. The ultra-high pressure, high temperature process uses a solid-phase nitrogen source to form GaN crystals in a metal alloy melt. Using a thermal gradient diffusion process, in which nitrogen dissolves in the high temperature region of the metal melt and diffuses to the lower temperature, lower solubility region, high quality crystals up to similar to0.5 mm in size were formed, as determined by scanning electron microscopy, X-ray diffraction, and micro-Raman analysis. (C) 2003 Published by Elsevier Science Ltd.