Low Cost Czochralski Crystal Growing Technology: Near Term Implementation of the Flat Plate Photovoltaic Cost Reduction of the Low Cost Solar Array Project. Fifth Quarterly Progress Report, April 1-June 30, 1980

摘要

During this reporting period, the primary activity has been to develop microprocessor control of the crystal growth process and to develop and demonstrate the accelerated crystal growth program. Accelerated recharging of the quartz crucible by the RF melting of polycrystalline silicon feed rods was deemphasized by JPL primarily due to the unavailability of suitable quality feed rods at an effective economical price. The development of the cold crucible program as an alternative method of crucible recharging was continued, but at a lower priority. Work continued on the accelerated crystal growth program. Crystal growth runs were made utilizing the water cooled work coil previously used in the RF polycrystalline silicon rod melting program. Accelerated growth rates were demonstrated but an oxide build-up on the cold surface of the work coil, resulting in heavy flaking and consequent falling of oxide into the melt, resulted in abandoning this approach and redesigning, evaluating, and demonstrating an alternative heat sink arrangement. All necessary parts were received for the cold crucible premelter and system was assembled and interfaced to the multiturn high voltage RF power supply. (ERA citation 05:036303)