SOI wafer and method for producing it

US8323403B2 · kind B2 · utility

Assignee

• Siltronic AG · DE

Inventors

• Dieter Graef · Biebertal, DE
• Markus Blietz · Tittmoning, DE
• Reinhold Wahlich · Burghausen, DE
• Alfred Miller · Emmerting, DE
• Dirk Zemke · Marktl, DE

Key dates

• Filing date: Jan 18, 2008
• Grant date: Dec 4, 2012
• Expiry date: Oct 6, 2031

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01L21/3226
• WIPO field: Surface technology, coating
• WIPO sector: Chemistry

Abstract

An SOI wafer is constructed from a carrier wafer and a monocrystalline silicon layer having a thickness of less than 500 nm, an excess of interstitial silicon atoms prevailing in the entire volume of the silicon layer. The SOI wafers may be prepared by Czochralski silicon single crystal growth, the condition v/G<(v/G)crit=1.3×10−3 cm2/(K·min) being fulfilled at the crystallization front over the entire crystal cross section, with the result that an excess of interstitial silicon atoms prevails in the silicon single crystal produced; separation of at least one donor wafer from this silicon single crystal, bonding of the donor wafer to a carrier wafer, and reduction of the thickness of the donor wafer, with the result that a silicon layer having a thickness of less than 500 nm bonded to the carrier wafer remains.