PROCESS FOR REMOVING METALLIC IMPURITIES FROM SILICON CARBIDE COATED COMPONENTS OF A SILICON SINGLE CRYSTAL PULLING APPARATUS

摘要

A process for reconditioning a structural component of a crystal pulling apparatus for reuse therein. The structural component comprises a graphite substrate and a first protect layer of silicon carbide or glassy carbon the substrate, and optionally, a second protective layer comprising silicon covering the first protective layer. During the process, the structural component, while in a treatment chamber, is exposed to an iron-complexing gas comprising a halogen at a temperature and for a duration sufficient to reduce an iron concentration in the structural component.