The evening discussion group program is regarded as a favorite highlight of the workshop experience. Attendees will have a choice of four topics on both Tuesday and Wednesday evenings. The same four topics will be discussed for 90 minutes each night. This year's topics are:

1. Interconnect Reliability - with a focus on copper

Moderators: Tim Sullivan (IBM) and Carl Thompson (MIT)

To meet anticipated requirements over the next 15 years, the U.S. National Technology Roadmap for Semiconductors (NTRS) charts an aggressive path for evolution of current interconnect technology. Insertion of new interconnect materials (Cu as the primary conductor, with refractory metal liners) is already underway, and, to stay on the NTRS timeline, insertion of new dielectric materials will be required in the near future. With interconnect lengths of kilometers per circuit, minimum line widths shrinking below 100nm, the number of metallization levels moving toward 10, and the use of an interconnect metal which must be fully isolated from the dielectric, enormous reliability challenges must be met during a period of rapid development of new materials and processes. The goals of this discussion group will be to identify areas of greatest concern, and share lessons learned, and anticipated needs.

Specific discussion topics will include:

• Can the same reliability approaches that were used for Al be applied to Cu?
• Is electromigration-induced failure still an issue for Cu-based alloys? What are the new design rules?; Are new design strategies enabled?, Are existing design strategies still OK?
• How do liners for Cu affect electromigration?
• Are there reliability issues with the liners themselves? How easy is it to insure that liners are continuous everywhere on a kilometer of interconnect?, Are there wear-out failure mechanisms for liners, such as cracking due to thermal cycling?, How can liner reliability be assessed?
• Are there new processing-related defects arising from Cu-based technologies which lead to reliability issues?, How important is Cu adhesion?, How significant are the differences in Cu deposition techniques?
• What are the implications of dual damascene vias?: Will liner integrity in vias be a problem?, Will aspect ratio uniformity be maintained ?, Will stress become an issue?
• How will the mechanical and thermal properties of Low-K dielectrics affect reliability?
• Are there other properties of Cu or Low-K, different from Al and SiO2, which could bring in unanticipated reliability challenges?