Ludovic Boyer Email & Phone Number

Lyon, Fr

Région De Lyon, France

Région De Montpellier, France

Power semiconductor devices are increasingly used as key parts of embedded power conversion sys­ tems in critical applications such as aerospace industry and ground transport. In such critical applications, these devices are submitted to harsh environments stresses which may significantly alter their reliability. A power semi­conductor device breakdown may induce catastrophic results in terms of human safety, as well as economical dimensions. There is, indeed, a continuous demand on an increas­ ing knowledge concerning the development of new characterization techniques for ageing monitoring of theses devices.The greatest part of this PhD work is focused on the monitoring of gate oxide properties evol­ utions of samples structures using the Capacitance­Voltage method (C­V method) and the Thermal Step Method (TSM), as well as applying them to power semi­conductor devices.Coupling TSM and C-V method was performed to approximately locate charge evolutions in the gate oxide of sample devices when submitted to electrical stresses comparable to the ones submitted to power semi-con­ ductor devices.Variations of gate-collector capacitance were pointed out when Injection Enhenced IGBTs were submitted to stresses comparable to the one encountered in ground transport applications. These variations may be related to an evolution of the gate oxide of the IGBTs correlated to their operating state.