Process for producing silicon semiconductor wafers with low defect density

US5935320A · kind A · utility

Assignee

• Wacker Siltronic Gesellschaft Fur Halbleitermaterialien AG · DE

Inventors

• Dieter Graef · Biebertal, DE
• Wilfried Ammon · Burghausen, DE
• Reinhold Wahlich · Burghausen, DE
• Peter Krottenthaler · Burghausen, DE
• Ulrich Lambert · Emmerting, DE

Key dates

• Filing date: Aug 26, 1997
• Grant date: Aug 10, 1999
• Expiry date: Aug 26, 2017

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S117/916
• WIPO field: Surface technology, coating
• WIPO sector: Chemistry

Abstract

A process for producing silicon wafers with low defect density is one wherein a) a silicon single crystal having an oxygen doping concentration of at least 4*10.sup.17 /cm.sup.3 is produced by molten material being solidified to form a single crystal and is then cooled, and the holding time of the single crystal during cooling in the temperature range of from 850.degree. C. to 1100.degree. C. is less than 80 minutes; b) the single crystal is processed to form silicon wafers; and c) the silicon wafers are annealed at a temperature of at least 1000.degree. C. for at least one hour. Also, it is possible to prepare a silicon single crystal based upon having an oxygen doping concentration of at least 4*10.sup.17 /cm.sup.3 and a nitrogen doping concentration of at least 1*10.sup.14 /cm.sup.3 for (a) above.