Copper interconnect with metal hardmask removal

US8664115B2 · kind B2 · utility

Assignee

• GlobalFoundries Inc. · KY

Inventors

• Christin Bartsch · Neustadt in Sachsen, DE
• Susanne Leppack · Dresden, DE

Key dates

• Filing date: Jun 10, 2011
• Grant date: Mar 4, 2014
• Expiry date: Mar 31, 2032

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01L21/76843
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

A passivation layer is formed on inlaid Cu for protection against oxidation and removal during subsequent removal of an overlying metal hardmask. Embodiments include treating an exposed upper surface of inlaid Cu with hydrofluoric acid and a copper complexing agent, such as benzene triazole, to form a passivation monolayer of a copper complex, etching to remove the metal hardmask, removing the passivation layer by heating to at least 300° C., and forming a barrier layer on the exposed upper surface of the inlaid Cu.