Aluminium corrosion in power semiconductor devices

Funding Information: The work presented in this publication has been carried out by an international research consortium at ABB Drives in Finland, at Aalto University (at Micronova and Nano Microscopy Center) in Finland, at University of Bremen in Germany, and at IWO Ede NL in the Netherlands. We extend special thanks to Jiaco Instruments for the support given by their demonstration of their MIP decapsulation technique which was used for the samples used in this article. We also extend our thanks to Fraunhofer IMWS in Germany for special permission to trial LiT equipment on one of the samples described in this work. The work has been partially funded by the Power2Power project , which is a co-funded European innovation project in the semiconductor industry. The project receives grants from the European H2020 research and innovation programme , the ECSEL Joint Undertaking and national funding authorities from the eight involved countries under grant agreement No 826417 . The participating countries are Austria, Finland, Germany (including the free states of Saxony and Thuringia), Hungary, the Netherlands, Slovakia, Spain and Switzerland. Funding Information: The work presented in this publication has been carried out by an international research consortium at ABB Drives in Finland, at Aalto University (at Micronova and Nano Microscopy Center) in Finland, at University of Bremen in Germany, and at IWO Ede NL in the Netherlands. We extend special thanks to Jiaco Instruments for the support given by their demonstration of their MIP decapsulation technique which was used for the samples used in this article. We also extend our thanks to Fraunhofer IMWS in Germany for special permission to trial LiT equipment on one of the samples described in this work. The work has been partially funded by the Power2Power project, which is a co-funded European innovation project in the semiconductor industry. The project receives grants from the European H2020 research and innovation programme, the ECSEL Joint Undertaking and national funding authorities from the eight involved countries under grant agreement No 826417. The participating countries are Austria, Finland, Germany (including the free states of Saxony and Thuringia), Hungary, the Netherlands, Slovakia, Spain and Switzerland. Publisher Copyright: © 2022 The Author(s) | openaire: EC/H2020/826417/EU//Power2Power In this study, insulated gate bipolar transistor (IGBT) power modules were exposed to high voltage, high humidity, high temperature and reverse bias (HV-H3TRB) conditions until end-of-life (EoL). The limited lifetime of power semiconductor devices when used in demanding applications involving high relative humidity during operation is commonly reported to be associated with the design of the edge termination in power transistor or diode chips. A physics-of-failure (PoF) oriented methodology was adopted in failure analysis, including using lock-in thermography (LiT) for failure localisation and using an advanced microwave-induced plasma (MIP) decapsulation technique for the selective etching of the edge termination polyimide passivation film. A focused ion beam (FIB) was utilised to create a cross-section of the samples for both scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) analysis. The evidence gathered using the physics-of-failure methodology were compared with the results from advanced statistical analysis of the failure distributions in Weibull plots, including comparison of α and β parameters. This analysis revealed correlation with the Weibull distributions and the results from the physics-of-failure. Aluminium corrosion products were systematically observed on guard rings (GR) and field plates (FP) showing that the migration of these corrosion products forming an electrical path between the guard rings that seems to be a major failure mechanism in high humidity environments when reverse bias voltage is applied.