Silicon wafer etching process and composition

US7323421B2 · kind B2 · utility

Assignee

• MEMC Electronic Materials, Inc. · US

Inventors

• Mark Stinson · East Alton, US
• Henry F. Erk · Chesterfield, US
• Guoqiang Zhang · Ballwin, US
• Mick Bjelopavlic · Chandler, US
• Alexis Grabbe · Albuquerque, US
• Jozef G. Vermeire · Holden, US
• Judith A. Schmidt · Overland, US
• Thomas E. Doane · Troy, US
• James Raymond Capstick · Florissant, US

Key dates

• Filing date: Jun 14, 2005
• Grant date: Jan 29, 2008
• Expiry date: Jun 24, 2025

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C11D2111/22
• WIPO field: Basic materials chemistry
• WIPO sector: Chemistry

Abstract

A process for etching silicon wafers using a caustic etchant in the form of an aqueous solution comprising water, a hydroxide ion source, and a chelating agent. The process produces silicon wafers substantially free from diffused metal ions.