Pad stack with a poly SI etch stop for TEOS mask removal with RIE

US5776808A · kind A · utility

Assignees

• Siemens Aktiengesellschaft · DE
• International Business Machines Corporation · US

Inventors

• Karl Paul Muller · Wappingers Falls, US
• Bernhard Poschenrieder · Saint-Cloud, FR
• Klaus Roithner · Aßling, DE

Key dates

• Filing date: Dec 26, 1996
• Grant date: Jul 7, 1998
• Expiry date: Dec 26, 2016

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01L21/31116
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

A method for allowing the removal of a TEOS etch mask layer utilizing an anisotropic technique such as reactive ion etching. The use of the anisotropic technique results in substantially less undercutting of the pad oxide layer than wet chemical etching techniques. One embodiment of the invention involves forming a polysilicon etch stop layer under the pad TEOS layer.