Method for dry etching of a semiconductor substrate

US5705025A · kind A · utility

Assignee

• Siemens Aktiengesellschaft · DE

Inventors

• Ralf Dietrich · Munich, DE
• Gerhard Franz · Marl, DE

Key dates

• Filing date: Oct 4, 1995
• Grant date: Jan 6, 1998
• Expiry date: Oct 4, 2015

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S438/978
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

A method for dry etching of a semiconductor substrate includes producing convex structures on a surface of a semiconductor wafer by using a suitable masking and a suitable etchant. A thick photoresist layer is applied to a semiconductor wafer and structured. The structured photoresist layer is liquified by the influence of temperature to produce a spherical structure and is then hardened as an etchable masking. The semiconductor wafer structured with the photoresist layer is etched in plasma at etching speeds being similar for the semiconductor material and the photoresist, for transferring a convex structure of the photoresist layer to the semiconductor wafer, during etching down of the photoresist layer.