Horizontal gradient-freeze growth of InP crystals under controlled pressure

The use of a horizontal gradient-freeze (HGF) method employing a sealed pressure-balanced system for synthesis and in situ crystal growth without encapsulation is described. The thermal stability of semi-insulating InP:Ti,Hg is discussed, and synthesis by conventional methods and by liquid-encapsulated Czochralski (LEC) growth is considered. Synthesis and HGF growth under controlled P pressure are then examined. Since the melt is not encapsulated, the P pressure can be adjusted to obtain the optimum melt composition for minimizing defect density, impurity contamination, and twinning. In addition, in situ growth prevents impurity contamination that can results when a growth charge synthesized in one system is transferred to a second system for crystal growth.<>