Dual etch stop/diffusion barrier for damascene interconnects

US6153935A · kind A · utility

Assignee

• International Business Machines Corporation · US

Inventors

• Daniel C. Edelstein · White Plains, US
• Timothy J. Dalton · Ridgefield, US
• John G. Gaudiello · Poughkeepsie, US
• Mahadevaiyer Krishnan · Hopewell Junction, US
• Sandra G. Malhotra · San Jose, US
• Maurice McGlashan-Powell · Yorktown Heights, US
• Eugene J. O'Sullivan · Nyack, US
• Carlos J. Sambucetti · Ossining, US

Key dates

• Filing date: Sep 30, 1999
• Grant date: Nov 28, 2000
• Expiry date: Sep 30, 2019

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01L21/76835
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

A damascene interconnect containing a dual etch stop/diffusion barrier. The conductive material of the damascene interconnect is capped with a conductive metal diffusion barrier cap, typically using electroless deposition, and, optionally, with a dielectric etch-stop layer. An optional chemical mechanical polish-stop layer may also be present. The different methods of the invention allow the CMP stop, reactive-ion etch stop, and metal diffusion barrier requirements of the different layers to be decoupled. A preferred conductive material is copper.