Improving yields through effective diagnostics: A MCM-D/C example

Partitioning of defects in process, tools, contamination and handling has been used effectively at the IBM Thin Films Packaging manufacturing facility for many years to track and improve yields. To design for manufacturability (DFM) means to take into consideration all the elements that affect yields, such as tooling, clean room environment process selection, ground rules, repairability and test. On multilevel structures, final test alone does not allow for effective diagnostics, since most yield losses occur from sub-level defects. Early feedback to establish root cause can be obtained via in-line test inspection and measurement. Also, it is at these sub-levels where surface repairs for opens and shorts can be done easily. This paper discusses how to improve yields through effective diagnostics. Specific examples illustrate how scattered plots, failure analysis, job traceability and correlations have been used on the IBM MCM-D/C manufacturing line for real time defect diagnosis.