Method of increasing minority carrier lifetime in silicon web or the like

US4401505A · kind A · utility

Assignee

• The United States of America as represented by the Administrator of the National Aeronautics and Space Administration · US

Inventors

• James Liu · Hsinchu, TW
• Guenter H. Schwuttke · Poughkeepsie, US
• Krishna M. Koliwad · Tustin, US

Key dates

• Filing date: Mar 31, 1982
• Grant date: Aug 30, 1983
• Expiry date: Mar 31, 2002

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S438/909
• WIPO field: Surface technology, coating
• WIPO sector: Chemistry

Abstract

A silicon dendrite is grown as a ribbon forming two silicon crystal layers which are separated by an interface layer which contains a large number of defects. Significant increase of minority carrier lifetime with homogeneous distribution at the outer surfaces of the two silicon crystal layers are achieved by processing the web in an atmosphere of a selected gas, e.g. oxygen, nitrogen or an inert gas, for about 30 minutes to several hours at a temperature preferably on the order of 900.degree. C.-1200.degree. C.