Method and apparatus for electroplating

US8308931B2 · kind B2 · utility

Assignee

• Novellus Systems, Inc. · US

Inventors

• Jonathan D. Reid · Sherwood, US
• Bryan L. Buckalew · Tualatin, US
• Zhian He · Beaverton, US
• Seyang Park · Beaverton, US
• Seshasayee Varadarajan · Lake Oswego, US
• Bryan Pennington · Sherwood, US
• Thomas A. Ponnuswamy · Sherwood, US
• Patrick Breling · Portland, US
• Glenn Ibarreta
• Steven T. Mayer · Lake Oswego, US

Key dates

• Filing date: Nov 7, 2008
• Grant date: Nov 13, 2012
• Expiry date: Jan 4, 2031

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01L21/76873
• WIPO field: Surface technology, coating
• WIPO sector: Chemistry

Abstract

An apparatus for electroplating a layer of metal on the surface of a wafer includes an ionically resistive ionically permeable element located in close proximity of the wafer (preferably within 5 mm of the wafer surface) which serves to modulate ionic current at the wafer surface, and a second cathode configured to divert a portion of current from the wafer surface. The ionically resistive ionically permeable element in a preferred embodiment is a disk made of a resistive material having a plurality of perforations formed therein, such that perforations do not form communicating channels within the body of the disk. The provided configuration effectively redistributes ionic current in the plating system allowing plating of uniform metal layers and mitigating the terminal effect.