Process and apparatus for etching semiconductor surfaces

US4971654A · kind A · utility

Assignee

• Wacker-Chemitronic Gesellschaft fur Elektronik Grundstoffe mbH · DE

Inventors

• Anton Schnegg · Burghausen, DE
• Gerhard Brehm · Emmerting, DE
• Helene Prigge · Unterschleißheim, DE
• Robert Rurlander · Burgkirchen an der Alz, DE
• Fritz Ketterl · Munich, DE

Key dates

• Filing date: Aug 8, 1988
• Grant date: Nov 20, 1990
• Expiry date: Aug 8, 2008

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01L21/30604
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

A process and apparatus for etching semiconductor surfaces, in particular, ilicon, with a mixture containing nitrogen-oxygen based compounds as oxidizing compounds, hydrofluoric acid as the component which dissolves the oxidation product, and sulfuric acid, optionally with phosphoric acid added, as a carrier medium. This mixture makes it possible to design the process as a cyclic process in which oxygen supplied to the system ultimately effects an oxidation of the material to be etched, and the product of its oxidation is removed from the circuit. The process is noteworthy for its low usage of reagents and because it is not harmful to the environment.