Contact etch stop layer with sacrificial polysilicon layer

US9991363B1 · kind B1 · utility

Assignee

• GlobalFoundries Inc. · KY

Inventors

• Haigou Huang · Rexford, US
• Jinsheng Gao · Clifton Park, US
• Haifeng Sheng · Rexford, US
• Jinping Liu · Ballston Lake, US
• Huy Cao · Rexford, US
• Hui Zang · Guilderland, US

Key dates

• Filing date: Jul 24, 2017
• Grant date: Jun 5, 2018
• Expiry date: Jul 24, 2037

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10D84/0135
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

A contact etch stop layer includes a nitride layer formed over a sacrificial gate structure and a polysilicon layer formed over the nitride layer. During subsequent processing, the polysilicon layer is adapted to oxidize and form an oxide layer. The oxidation of the polysilicon layer effectively shields the underlying nitride contact etch stop layer from oxidation, which protects the mechanical integrity of the nitride layer.