Method of removing damaged crystal regions from silicon wafers

US5911889A · kind A · utility

Assignee

• Wacker Siltronic Gesellschaft Fur Halbleitermaterialien AG · DE

Inventors

• Laszlo Fabry · Burghausen, DE
• Bernd Passer · Burghausen, DE
• Edeltraud Steiger · Falkenberg, DE

Key dates

• Filing date: Apr 8, 1996
• Grant date: Jun 15, 1999
• Expiry date: Apr 8, 2016

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01L21/02019
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

A method is provided to remove crystal regions from silicon wafers which are damaged as a consequence of mechanical machining of the silicon wafers. The silicon wafers are pretreated with an aqueous solution containing hydrogen fluoride. Then the wafers are etched in an aqueous solution exposed to ultrasound and containing alkali metal hydroxide at temperatures from 55.degree. C. to 95.degree. C.