Detectability of Automotive Power MOSFET On-Resistance Failure at High Current Induced by Wafer Fab Process Excursion

This paper presents the meaningful consequence of a minor Wafer Fab process variability, generating on-resistance drift on low voltage vertical power N-MOSFETs dedicated to microhybrid automotive application. The originality of this paper concerns the necessity to use complementary failure analysis investigations needed to determine the origin of the failure without any possibilities to perform any fault localization. The results enabled implementation of corrections and improvement of test screening to protect customers.