Device and method for stopping etching process

US9305798B2 · kind B2 · utility

Assignee

• Infineon Technologies AG · DE

Inventors

• Lothar Brencher · Radeberg, DE
• Dirk Meinhold · Dresden, DE
• Michael Hartenberger · Dresden, DE
• Georg Seidemann · Landshut, DE
• Wolfgang Dickenscheid · Dresden, DE

Key dates

• Filing date: Mar 25, 2013
• Grant date: Apr 5, 2016
• Expiry date: May 3, 2033

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01L21/76877
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

A method for etching a layer assembly, the layer assembly including an intermediate layer sandwiched between an etch layer and a stop layer, the method including a step of etching the etch layer using a first etchant and a step of etching the intermediate layer using a second etchant. The first etchant includes a first etch selectivity of at least 5:1 with respect to the etch layer and the intermediate layer. The second etchant includes a second etch selectivity of at least 5:1 with respect to the intermediate layer and the stop layer. The first etchant being is different from the second etchant.