Crucibleless zone melting, for large semiconductor stock - using induction coil with additional radiation source at jagged fringe

摘要

A crucibleless zone melting process for a vertical semi-conductor crystal rod (a single silicon crystal) uses an annular inductive heating coil of smaller inside dia. than the outside dia. of the stock. Additional radiation energy (a focussed high-energy light beam, a laser beam or a high-energy electrom beam) is directed to the stock in the area of the melting zone fringe. Stock with a large dia., which is preferred for economy reasons, can now be utilised for the pulling of single crystals of large dia.