Semiconductor device comprising a contact structure based on copper and tungsten

US7902581B2 · kind B2 · utility

Assignee

• GlobalFoundries Inc. · KY

Inventors

• Kai Frohberg · Meißen, DE
• Carsten Peters · Dresden, DE
• Thomas Werner · Radebeul, DE

Key dates

• Filing date: Jul 5, 2006
• Grant date: Mar 8, 2011
• Expiry date: Jan 21, 2029

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01L2924/0002
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

By providing contact plugs having a lower plug portion, formed on the basis of well-established tungsten-based technologies, and an upper plug portion, which may comprise a highly conductive material such as copper or a copper alloy, a significant increase in conductivity of the contact structure may be achieved. For this purpose, after the deposition of a first dielectric layer of the inter-layer stack, a planarization process may be performed so as to allow the formation of the lower plug portions on the basis of tungsten, while, after the deposition of the second dielectric layer, a corresponding copper-based technology may be used for forming the upper plug portions of significantly enhanced conductivity.