Continuous Czochralski Growth. Silicon Sheet Growth Development of the Large Area Silicon Sheet Task of the Low Cost Silicon Solar Array Project. First Annual Progress Report, October 1, 1977--September 30, 1978

摘要

The primary objective of this work is to develop equipment and methods for the economic production of single crystal ingot material by the continuous Czochralski (CZ) process. Continuous CZ is defined for the purpose of this work as the growth of at least 100 kilograms of ingot from only one melt container. The approach to the project is to utilize a Hamco production CG2000 crystal grower suitably modified to grow large crystals and to permit periodic replenishment of the liquid. Key modifications were a vacuum tight isolation valve to separate the furnace chamber from the pull chamber for recharging, an automatic recharge mechanism, and an enlarged pull chamber to hold a supply of poly material. Other suitable modifications to permit the growth of crystals up to about 35 kilograms each included an optical diameter control system to allow crystals up to 12.5 cm to be grown, and a pull mechanism capable of supporting the large crystal to be grown. Furnace hot zone modifications were designed and built to accomodate 14-inch diameter crucibles having a melt capacity of about 40 kilograms. Progress is reported. (ERA citation 04:044494)