Effective Method for Analyzing IGBT Leakage Failures Related to the Exposed Junction on the Die Sidewall

An effective method is presented to locate certain failure sites on exposed junction of insulated-gate bipolar transistor (IGBT) devices. High emitter to collector leakage current, hereafter called ICESR, is an IGBT failure mode. The leakage current is typically related to the exposed P+/N+ junction on the die sidewall. Solder die attach residue bridging or silicon damage at this exposed P+/N+ junction are common causes of ICESR leakage. The die attach residue can be dislodged during decapsulation resulting in loss of failure information. A failure analysis flow will be described to precisely locate the ICESR leakage site without disturbing any possible die attach residue.