Selective etching processes of silicon nitride and indium oxide thin films for FeRAM device applications

US7338907B2 · kind B2 · utility

Assignee

• Sharp Laboratories of America, Inc. · US

Inventors

• Tingkai Li · Vancouver, US
• Sheng Teng Hsu · Camas, US
• Bruce D. Ulrich · Beaverton, US
• Mark Burgholzer · Amboy, US
• Ray Hill · Vancouver, US

Key dates

• Filing date: Oct 4, 2004
• Grant date: Mar 4, 2008
• Expiry date: Apr 9, 2025

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10D30/701
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

A dry etch process is described for selectively etching silicon nitride from conductive oxide material for use in a semiconductor fabrication process. Adding an oxidant in the etch gas mixture could increase the etch rate for the silicon nitride while reducing the etch rate for the conductive oxide, resulting in improving etch selectivity. The disclosed selective etch process is well suited for ferroelectric memory device fabrication using conductive oxide/ferroelectric interface having silicon nitride as the encapsulated material for the ferroelectric.