Correlation of Wafer Level QA Tests with Functional Device Yield and AcceleratedLife Test Results

摘要

This report covers work that was to correlate wafer level test structure testswith life tests by utilizing test structures collocated with a RAM-like device. Wafer level tests for oxide breakdown, electromigration, and hot carrier degradation were conducted on a total of six wafer lots from three vendors. Functional testing of the RAM-like device yielded just over six hundred devices to be packaged for the life test. The data from the wafer level and life testing indicate that the oxide breakdown wafer level test is able to be correlated to both functional yield and life test results. This study was not able to conclusively correlate the wafer level electromigration or hot carrier testing to the life test results. Further study with a much larger sample size and a longer life test needs to be performed to further address this issue. jg.