Planarization of a non-conformal device layer in semiconductor fabrication

US5880007A · kind A · utility

Assignees

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

Inventors

• Kathryn H. Varian · Hopewell Junction, US
• Dirk Tobben · Fishkill, US
• Matthew Sendelbach · Fishkill, US

Key dates

• Filing date: Sep 30, 1997
• Grant date: Mar 9, 1999
• Expiry date: Sep 30, 2017

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01L21/31053
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

A substantially planar surface is produced from a non-conformal device layer formed over a complex topography, which includes narrow features with narrow gaps and wide features and wide gaps. A conformal layer is deposited over the non-conformal layer. The surface is then polished to expose the non-conformal layer over the wide features. An etch selective to the non-conformal layer is then used to substantially remove the non-conformal layer over the wide features. The conformal layer is then removed, exposing the non-conformal layer. The thickness of the non-conformal layer is now more uniform as compared to before. This enables the polish to produce a planar surface with reduced dishing in the wide spaces.