Study Czochralski Liquid-Seal Crystal Growing Technique.

N-Type, P-Type and semi-insulating Chrome dope single crystals of Gallium Arsenide were grown using the Czochralski Liquid-Seal Technique. Boron Nitride was selected as the crucible material that would yield the best quality single crystals. Single Gallium Arsenide crystals of up to 300 grams were grown as a result of modifications made in the puller apparatus. Experiments were conducted to identify the cause of impurity contamination during the growth process. The results of these experiments indicated that 1 The introduction of Boron Oxide B2O3 to the Gallium Arsenide melt absorbed impurities. 2 Silicon si was being introduced to the melt by the breakdown of the quartz 2SiO2 2SiOO2. This was caused by the natural gas-oxygen torch, which heats the quartz chamber to prevent Gallium Arsenide condensation. 3 A special viewport, heated by a resistance furnace rather than a natural gas-oxygen torch was used to reduce silicon contaminants. As a result of this experiment, an undoped semi-insulating crystal of extremely high purity was grown. Author