Methods of controlling the etching of silicon nitride relative to silicon dioxide

US8580133B2 · kind B2 · utility

Assignee

• GlobalFoundries Inc. · KY

Inventors

• Berthold Reimer · Dresden, DE
• Claudia Wolf · Saarmund, DE

Key dates

• Filing date: Nov 14, 2011
• Grant date: Nov 12, 2013
• Expiry date: Jan 18, 2032

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01L21/67086
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

Disclosed herein are methods of controlling the etching of a layer of silicon nitride relative to a layer of silicon dioxide. In one illustrative example, the method includes providing an etch bath that is comprised of an existing etchant adapted to selectively etch silicon nitride relative to silicon dioxide, performing an etching process in the etch bath using the existing etchant to selectively remove a silicon nitride material positioned above a silicon dioxide material on a plurality of semiconducting substrates, determining an amount of the existing etchant to be removed based upon a per substrate silicon loading of the etch bath by virtue of etching the plurality of substrates in the etch bath and determining an amount of new etchant to be added to the etch bath based upon a per substrate silicon loading of the etch bath by virtue of etching the plurality of substrates in the etch bath.