Wafer Level Reliability Utilization and Trends

This discussion group sought to bring greater understanding of the types and amount of wafer level reliability testing that are used throughout the semiconductor industry. With a greater understanding of what each company is actually practicing in their individual WLR efforts and how these programs have benefited reliability improvements in products, we can change or expand our existing programs uo provide added value. VVe are also looking to highlight the difference between WLR testing that is used as a ongoing monitor and testing that is a true reliability indicator for product. The ultimate goal is to be able to make fact and data based decisions from wafer level testing to prevent us from having to rely on lengthy package level testing results. 'The discussion group was structured to fist identify some of the reasons that we are currently forced to disposition deviate product without the appropriate data. When engineering level data is not available, the decision making process can default to non data based decision making due to issues like economics, time, conjecture, or misuse of data. The second step was to identify the WLR activities and capabilities of the companies represented and the failure mechanism each test monitors or targets. This is a good industry poll of the actual activities in use or final development today and served to show the level of WLR implementation throughout the industry. Slide 2 shows these results. The next step is to identify the actual reliability issues we see today within our industry or companies. These are supposed to be actual failure mechanisms seen today and not mechanisms that monitors are in place to detect. With a comprehensive list of these failure mechanisms, we can identify the existing WLR testing available for the mechanism or identify mechanisms for which we have no current method of testing with current WLR methodologies. Slides 3 & 4 shows the resulting list of failure mechanisms and the WLR tests identified to address these mechanisms. The discussion showed that the companies using particular WLR tests were not necess