Selective formation of porous silicon

US5421958A · kind A · utility

Assignee

• The United States of America as represented by the Administrator of the United States National Aeronautics and Space Administration · US

Inventors

• Robert W. Fathauer · Burbank, US
• Eric Jones · Los Angeles, US

Key dates

• Filing date: Jun 7, 1993
• Grant date: Jun 6, 1995
• Expiry date: Jun 7, 2013

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01L21/306
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

A pattern of porous silicon is produced in the surface of a silicon substrate by forming a pattern of crystal defects in said surface, preferably by applying an ion milling beam through openings in a photoresist layer to the surface, and then exposing said surface to a stain etchant, such as HF:HNO.sub.3 :H.sub.2 O. The defected crystal will preferentially etch to form a pattern of porous silicon. When the amorphous content of the porous silicon exceeds 70% the porous silicon pattern emits visible light at room temperature.