Process for wafer backside polymer removal with a ring of plasma under the wafer

US7552736B2 · kind B2 · utility

Assignee

• Applied Materials, Inc. · US

Inventors

• Kenneth S. Collins · San Jose, US
• Hiroji Hanawa · Sunnyvale, US
• Andrew Nguyen · San Jose, US
• Ajit Balakrishna · Sunnyvale, US
• David Palagashvili · Mountain View, US
• James P. Cruse · Santa Cruz, US
• Jennifer Y. Sun · Mountain View, US
• Valentin Todorov · Fremont, US
• Shahid Rauf · Pleasanton, US
• Kartik Ramaswamy · San Jose, US
• Gerhard Schneider · Cupertino, US
• Imad Yousif · San Jose, US
• Martin Jeffrey Salinas · Campbell, US

Key dates

• Filing date: Mar 14, 2007
• Grant date: Jun 30, 2009
• Expiry date: Mar 14, 2027

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01L21/68728
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

A process is provided for removing polymer from a backside of a workpiece. The process includes supporting the workpiece on the backside in a vacuum chamber while leaving at least a peripheral annular portion of the backside exposed. The process further includes confining gas flow at the edge of the workpiece within a gap at the edge of the workpiece on the order of about 1% of the diameter of the chamber, the gap defining a boundary between an upper process zone containing the wafer front side and a lower process zone containing the wafer backside. The process also includes providing a polymer etch precursor gas underneath the backside edge of the workpiece and applying RF power to a region underlying the backside edge of the workpiece to generate a first plasma of polymer etch species concentrated in an annular ring concentric with and underneath the backside edge of the workpiece.