Electrical breakdown in polymers for BEOL applications: Dielectric heating and humidity effects

Polymer dielectrics may be used as low-k BEOL dielectrics, however, premature electrical breakdown due to high electric fields, high frequencies and ambient humidity conditions have restricted its widespread adoption. In this study, we show that dielectric heating is the primary AC degradation mechanism in polymer dielectrics, and develop an analytical model that is consistent with measured trends in stress tests under both AC and DC electric fields. We also study the effect of exposure to ambient relative humidity on the lifetime of polymer dielectrics.