Development of Advanced Czochralski Growth Process to Produce Low Cost 150 Kg Silicon Ingots from a Single Crucible for Technology Readiness. Fifth Quarterly Progress Report, October 1-December 31, 1981

摘要

The emphasis for these last months of the contract will include continued investigation of (1) throughput rate using a cone-shaped radiation/purge shield and (2) crucible-melt interaction with the Furnace Gas Analysis System. Availability of crucibles with minimum bubble content and/or synthetic quartz will also be investigated. Six growth runs used the Kayex-Hamco Automatic Grower Logic (AGILE) computer based system for growth from larger melts in the Mod CG2000. Also, the implementation of the melt pyrometer sensor allowed for dip-temperature monitoring and usage by the operator/AGILE system. Use of the AGILE during recharge operations was successfully evaluated. The tendency of crystals to lose cylindrical shape (spiraling) still continues to be a problem. The hygrometer was added to the Furnace Gas Analysis System and used on several growth runs. The gas chromatograph, including the integrator, was also used for more accurate carbon monoxide concentration measurements. Efforts continued for completing the automation of the total Gas Analysis System. The oxygen analyzer was added in late December, but preliminary tests indicate it will not measure properly at the reduced pressure of the crystal grower atmosphere. An economic analysis, based on revised achievable straight growth rate, is presented. The throughput is 1.92 kg/hour. When achieved, the program goal of 2.5 kg/hour will result in an additional 15.3% reduction in CZ add-on cost. (ERA citation 07:049690)