Harold Robert Perry

US Patent:

6773571, Aug 10, 2004

Filed:

May 22, 2002

Appl. No.:

10/154082

Inventors:

Steven T. Mayer - Lake Oswego OR
Evan E. Patton - Portland OR
Brian Paul Blackman - Woodburn OR
Jonathan D. Reid - Sherwood OR
Thomas Anand Ponnuswamy - Tualatin OR
Harold D. Perry - Eugene OR

Assignee:

Novellus Systems, Inc. - San Jose CA

International Classification:

C25D 500

US Classification:

205 96, 204232, 204242, 204272, 2042751, 204280, 2042861, 205123, 205148, 205157, 205291, 205292

Abstract:

The present invention pertains to methods and apparatus for electroplating a substantially uniform layer of a metal onto a work piece having a seed layer thereon. The total current of a plating cell is distributed among a plurality of anodes in the plating cell in order to tailor the current distribution in the plating electrolyte to compensate for resistance and voltage variation across a work piece due to the seed layer. Focusing elements are used to create âvirtual anodesâ in proximity to the plating surface of the work piece to further control the current distribution in the electrolyte during plating.