Strontium doping of molten silicon for use in crystal growing process

• Main Authors: Phillips, Richard Joseph, Keltner, Steven Jack, Holder, John Davis
• Format: Patent
• Language: English
• Published: 26.02.2002

The present invention relates to a process for doping molten silicon for use in a crystal growing process. More particularly, the present invention relates to a process for doping molten silicon with strontium for use within a silica crucible to cause the formation of a thin devitrified layer of silica to form on the inside crucible walls during melting of the polysilicon and throughout the ingot growing process without significant strontium incorporation in the growing ingot. A process for preparing strontium doped molten silicon for use in a single silicon crystal growing process is disclosed. Polysilicon is doped strontium and melted in a silica crucible. During melting and throughout the crystal growing process the strontium acts as a devitrification promoter and creates a layer of devitrified silica on the inside crucible surface in contact with the melt resulting in a lower level of contaminants in the melt and grown crystal.