Method and system for forming a silicon ingot using a low-grade silicon feedstock

US7955433B2 · kind B2 · utility

Assignee

• Calisolar, Inc. · US

Inventors

• Fritz Kirscht · Berlin, DE
• Vera Abrosimova · Berlin, DE
• Matthias Heuer · Berlin, DE
• Dieter Linke · Berlin, DE
• Jean Patrice Rakotoniana · Berlin, DE
• Kamel Ounadjela · Belmont, US

Key dates

• Filing date: Jul 26, 2007
• Grant date: Jun 7, 2011
• Expiry date: Oct 21, 2029

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10T117/1024

Abstract

Techniques for the formation of a silicon ingot using a low-grade silicon feedstock include forming within a crucible device a molten silicon from a low-grade silicon feedstock and performing a directional solidification of the molten silicon to form a silicon ingot within the crucible device. The directional solidification forms a generally solidified quantity of silicon and a generally molten quantity of silicon. The method and system include removing from the crucible device at least a portion of the generally molten quantity of silicon while retaining within the crucible device the generally solidified quantity of silicon. Controlling the directional solidification of the generally solidified quantity of silicon, while removing the more contaminated molten silicon, results in a silicon ingot possessing a generally higher grade of silicon than the low-grade silicon feedstock.