High melt temperature and thermal decomposition prevent the use of standard bulk semiconductor crystal growth processes for the production of GaN. We have employed a hydrostatic pressure system to grow GaN crystals. An ultrahigh pressure, high temperature process was developed using a solid-phase nitrogen source to form GaN crystals in a Ga metal 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 ϳ1 mm in size were formed, as determined by scanning electron microscopy, x-ray diffraction, and micro-Raman analysis.

The results of an experimental study ofthe performance of very high density 8, 128, and 256 bit CCD shift register structures are presented. The primary topics discussed include transfer efficiency, frequency response, impact of "fat zero" operation, and observed temperature dependency. Figure 1 Schematic representation of a portion of a threephase CCD and associated phase timing.

The use of standard bulk semiconductor crystal growth processes for the production of GaN is prohibited by both the high melt temperature of GaN and thermal decomposition of the compound into Ga metal and N2 gas. We have employed a novel hydrostatic pressure system to grow GaN crystals. A high temperature, ultra-high pressure process was developed using a solid-phase nitrogen source to form GaN crystals in a Ga metal 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 ∼1 mm in size were formed, as determined by SEM, X-ray diffraction and micro-Raman analysis.