Selective etching process

US4871420A · kind A · utility

Assignee

• American Telephone and Telegraph Company, AT&T Bell Laboratories · US

Inventors

• Frank B. Alexander, Jr. · Paterson, US
• Pang Dow Foo · Singapore, SG
• Ronald J. Schutz · Hackettstown, US

Key dates

• Filing date: Feb 10, 1988
• Grant date: Oct 3, 1989
• Expiry date: Feb 10, 2008

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01L21/3065
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

By adjusting the AC field conditions, i.e., by grounding the environment of a substrate being etched with a chlorine-containing plasma, a significant increase in etch selectivity is achieved. By applying a similar AC field adjustment to the reaction chamber surfaces, excellent etch uniformity is achieved in conjunction with excellent selectivity.