Process for producing a silicon single crystal which is doped with highly volatile foreign substances

US7070649B2 · kind B2 · utility

Assignee

• Siltronic AG · DE

Inventors

• Martin Weber · Borgo San Lazzaro, DE
• Peter Vilzmann · Burghausen, DE
• Erich Gmeilbauer · St. Pantaleon, AT
• Robert Vorbuchner · Burghausen, DE

Key dates

• Filing date: Oct 21, 2003
• Grant date: Jul 4, 2006
• Expiry date: Mar 21, 2024

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C30B15/00
• WIPO field: Surface technology, coating
• WIPO sector: Chemistry

Abstract

A process for producing a doped silicon single crystal, comprising after-doping the melt during the pulling process with a quantity of volatile dopant ΔN(t), calculated according to the equationΔN(t)=N0−N(t)=N0·(1−e−λ·t)or according to the approximation equationΔN(t)=N0·λa·twhere λa is an evaporation coefficient which describes process-specific evaporation behavior of the foreign substance and which is obtained after a resistance profile R(t) of a further single crystal has been measured and calculated according to the equationR(t)=R0·eλ·t,where R0 is a starting resistivity and the further single crystal is pulled under the same process conditions without being after-doped with the foreign substance.