Ozone treatment for selective silicon nitride etch over silicon

US11043393B2 · kind B2 · utility

Assignees

• Mattson Technology, Inc. · US
• Beijing E-Town Semiconductor Technology Co., Ltd. · CN

Inventors

• Shanyu Wang · Fremont, US
• Ting Xie · Burtonsville, US
• Chun Yan · San Jose, US
• Xinliang Lu · Fremont, US
• Hua Chung · San Jose, US
• Michael X. Yang · Palo Alto, US

Key dates

• Filing date: Jan 16, 2020
• Grant date: Jun 22, 2021
• Expiry date: Jan 16, 2040

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01L21/32105
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

Apparatus, systems, and methods for processing a workpiece are provided. In one example implementation, the workpiece can include a silicon nitride layer and a silicon layer. The method can include admitting an ozone gas into a processing chamber. The method can include exposing the workpiece to the ozone gas. The method can include generating one or more species from a process gas using a plasma induced in a plasma chamber. The method can include filtering the one or more species to create a filtered mixture. The method can further include exposing the workpiece to the filtered mixture in the processing chamber such that the filtered mixture at least partially etches the silicon nitride layer more than the silicon layer. Due to ozone gas reacting with surface of silicon layer prior to etching process with fluorine-containing gas, selective silicon nitride etch over silicon can be largely promoted.