Method of plasma etching of silicon carbide

US6670278B2 · kind B2 · utility

Assignee

• Lam Research Corporation · US

Inventors

• Si Yi Li · Fremont, US
• Helen Zhu · Santa Clara, US
• S. M. Reza Sadjadi · Saratoga, US
• David R. Pirkle · Soquel, US
• James R. Bowers · Atlanta, US
• Michael Goss · Hearst, CA

Key dates

• Filing date: Mar 30, 2001
• Grant date: Dec 30, 2003
• Expiry date: Mar 30, 2021

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01L21/76807
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

The invention provides a process for plasma etching silicon carbide with selectivity to an overlapping and/or underlying dielectric layer of material. The etching gas includes a hydrogen-containing fluorocarbon gas such as CH3F, an oxygen-containing gas such as O2 and an optional carrier gas such as Ar. The dielectric material can comprise silicon dioxide, silicon nitride, silicon oxynitride or various low-k dielectric materials including organic low-k materials. In order to achieve a desired selectivity to such dielectric materials, the plasma etch gas chemistry is selected to achieve a desired etch rate of the silicon carbide while etching the dielectric material at a slower rate. The process can be used to selectively etch a hydrogenated silicon carbide etch stop layer or silicon carbide substrates.