PROCESS AND APPARATUS FOR PREPARATION OF SILICON CRYSTALS WITH REDUCED METAL CONTENT

摘要

A method and apparatus for producing silicon single crystals with reduced contamination is disclosed. In one embodiment the structural components constructed of graphite and located in the hot zone of the crystal pulling apparatus have two protective layers. The first protective layer is applied directly to the graphite component. The second protective layer is a silicon layer and is applied on top of the first protective layer and covers the first layer. In a second embodiment, the structural components constructed of graphite and located in the hot zone of the crystal pulling apparatus have a single protective layer. The single protective layer is applied directly to the graphite and consists of a mixture of silicon carbide and silicon.