Plasma etching carbonaceous layers with sulfur-based etchants

US8133819B2 · kind B2 · utility

Assignee

• Applied Materials, Inc. · US

Inventors

• Judy Wang · Cupertino, US
• Shawming Ma · Sunnyvale, US
• Chang-Lin Hsieh · San Jose, US
• Bryan Liao · Saratoga, US
• Jie Zhou · Hefei, CN
• Hun Sang Kim · San Ramon, US

Key dates

• Filing date: Feb 21, 2008
• Grant date: Mar 13, 2012
• Expiry date: Jan 13, 2031

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01L21/31138
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

Etching of carbonaceous layers with an etchant gas mixture including molecular oxygen (O2) and a gas including a carbon sulfur terminal ligand. A high RF frequency source is employed in certain embodiments to achieve a high etch rate with high selectivity to inorganic dielectric layers. In certain embodiments, the etchant gas mixture includes only the two components, COS and O2, but in other embodiments additional gases, such as at least one of molecular nitrogen (N2), carbon monoxide (CO) or carbon dioxide (CO2) may be further employed to etch to carbonaceous layers.