Analysis of electromigration test data

Wafer level electromigration test is now a common practice in the semiconductor industry. Among the various fast wafer level electromigration tests, wafer level isothermal joule heated electromigration test (WIJET) is found to be most accurate for predicting the lifetime of metal line in ULSI. In order to reduce the test time, the temperature and current density of WIJET is usually increased to a high level. However, this could violate the important basic requirements of accelerated life testing (ALT), i.e. only one failure mechanism occurring during ALT, and the failure mechanism is the same as that under normal operating condition. In this work, the effect of temperature during WIJET on the fulfillment of these two requirements will be examined.