Yousef Re...These are generally process defects that are randomly distributed
on the wafer (many times though there are patterns to the defects - like
the edge has more than the center of the wafer). So defect density (DD) is the
number of "killer" defects per square cm of wafer area. <<<<<<<<
Please pardon my ignorance,your answer was quite clear, but I have a couple of follow up questions. Here you say that DD can have patterns, which intuitively seems to indicate that DD are caused by process problems,bad interconnects etc., however some have indicated that particulates are the main problem. Would these particulates necessary would be in the silicon material , or are they talking about contamination during processing, and would they be associated with patterns.
From your description it would seem DD encompasses any type of killer defect. When you and Elmer state that AMD has DD problems, that only seems to eliminate bin speed and leakage problems as the source of AMD alledged problems. Can you define better what kind of DD problems you or Elmer are talking about, and why you believe that that is the problem. . Bad interconnects for example, or fuzzy imaging, bad DD methadology, etc. If we had something specific, it would be easier to say " You know what, Yousef said AMD had problems with yields because of imaging problems which leads blah,blah." Then we would have an idea of why you feel that DD is causing a bad yield problem for AMD. |
