Methods for anisotropic etch of silicon-based materials with selectivity to organic materials

US11342195B1 · kind B1 · utility

Assignee

• TOKYO ELECTRON LIMITED · JP

Inventors

• Yun Han · Albany, US
• Peter Ventzek · Austin, US
• Alok Ranjan · Austin, US

Key dates

• Filing date: Feb 4, 2021
• Grant date: May 24, 2022
• Expiry date: Feb 4, 2041

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01L21/31144
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

Improved process flows and methods are provided that use a cyclic dry process to transfer a pattern from a patterned organic layer to an underlying silicon-containing layer. The cyclic dry process disclosed herein includes a deposition step, an etch step and a purge step, which may be repeated a number of cycles to progressively etch the exposed portions of the silicon-containing layer. Unlike conventional pattern transfer processes, the cyclic dry process described herein anisotropically etches the silicon-containing layer with high selectivity to the patterned organic layer. In doing so, the disclosed process improves pattern transfer performance and avoids problems typically seen in conventional pattern transfer processes such as, e.g., CD enlargement, CD distortion and/or complete loss of photoresist.