SiC JFETs for Power Module Applications

Abstract

Starting with the production of Infineon´s first silicon carbide (SiC) Schottky diodes in 2001, a lot of progress was achieved during recent years. Currently, a 3rd generation of MPS (merged pn Schottky) diodes is commercially available combining tremendous improvements with respect to surge current capability and reduced thermal resistance. In this work we present the implementation of SiC switches in power modules and a comparison of these units with the corresponding Si-based power modules. Also the frequency dependence of the total losses of the 1200V configurations using Si-IGBTs or SiC-JFETs as active device is shown, indicating that modules solution with a state of the art SiC JFET outperforms all other options for switching frequencies of 20 kHz and beyond. Additionally a total loss vs. frequency study will be presented. Furthermore, it is show that the switching losses of JFET based modules can be further reduced by reducing the internal distributed gate resistivity.