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An interview with Tom Long, vice president of corporate marketing, on KLA-Tencor’s recently introduced process module control solution for copper interconnects
Q
There’s a lot of talk in the industry about the difficulty in achieving acceptable yields with copper. What are you hearing about this from your customers?
A
There are a number of new process challenges associated with copper that relate to scale design rules, new insulator materials, the new dual damascene architecture and new deposition processes like electroplating, as well as new types of CMP processes for copper. Customers have a lot of learning to do and the yields in copper are typically less than 50 percent of what they are in aluminum today. This provides great opportunities for us to work with customers to improve their yields.
Q What do you think are
the biggest yield challenges in the transition to copper?
A The most significant yield issues
revolve around dual damascene, high aspect ratio structures and the successful filling of those structures with copper to prevent void formation. In order to eliminate those voids one has to opti-
mize the lithography, etch and film deposition processes — all of which are interrelated. In addition, the detection of defects in the dual damascene structure is different from the normal subtractive aluminum structure. With aluminum the interconnect structure is all above the surface; with copper, it is buried below. This makes defect detection much more challenging. The introduction of the eS20 in-line e-beam inspection system provides an unmatched capability to solve these problems.
Q
When do you see the semiconductor industry realizing copper yields at levels equal to aluminum processes?
A
Most customers are achieving between 5 and 50 percent of the equivalent aluminum yield with their copper processes. We believe over the period of the next year that some of the leaders will begin to approach the level of yields they have come to expect with aluminum, but only through the use of unique defect and metrology solutions such as those provided by KLA-Tencor. Autumn 1999
Q
KLA-Tencor recently announced its CuPMC solution. What does it consist of?
A Our CuPMC utilizes all of our
defect inspection and metrology tools and our analysis software, as well as our extensive yield management consulting and applications expertise. These components are all focused on the yield and control problems experienced in the film, litho, etch and CMP process modules that are involved in building copper interconnects. KLA-Tencor is the only company offering such comprehensive solutions applied to the copper yield problem.
Q
How many customers do you have using or planning to use your CuPMC?
A
All of the top Cu development fabs in the world today utilize a very high proportion of our overall Cu process module control solution including defect detection, metrology control, analysis software, and applications expertise.
Yield Management Solutions
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