Development of Advanced Methods for Continuous Czochralski Growth. Silicon Sheet Growth Development for the Large Area Silicon Sheet Task of the Low-Cost Silicon Solar Array Project. Second Quarterly Progress Report, January 1, 1978--March 17, 1978

摘要

The program has progressed to the final assembly of the recharging system on the Czochralski furnace. All components are in place and functional, and the modified furnace is being tested prior to the start of process development. The feasibility of a 100 kg continuous growth process has been demonstrated by a recharge simulation comprising six melt/pull cycles with a single 20 kg charge; the total body length was 249 cm (98 inch) with a calculated mass of 106 kg. Growth conditions were maintained for 67 hours with neither machine malfunction, excessive SiO accumulation, nor crucible failure. Examination of the crucibles revealed that devitrification and deformation are primarily responsible for the decrease in the wall thickness, which reaches approximately 50% of the minimum starting thickness at the locus of maximum attack--the corner radius. The crucibles also showed no adherence to the residual charge, which may be due to the surface structure produced by the long-term exposure of the silica to molten silicon. (ERA citation 03:049778)