Interfacial degradation of epoxy-coated silicon nitride

A silicon (Si) wafer passivated with a nitride film, fabricated by low-pressure chemical vapor deposition, and coated with epoxy was used as a test specimen to characterized the interfacial degradation. The highly accelerated stress test (HAST) conditions were 121°C and unsaturated 100% relative humidity. Optical microscopy was used to monitor the growth of damage as a function of time. Results of electron microscopy and X-ray photoelectron spectrometry (XPS) indicate that two different failure modes exist at the interface