Hybrid power module with Diamond and SiC power devices: modeling, performances and challenges
Résumé
Ultra wide bandgap (UWBG) materials such as monocrystalline Diamond are foreseen as the nextgeneration power semiconductor devices [1], whereas wide bandgap (WBG) materials such as SiC and GaN are already pushing towards more efficient and more integrated power converters [2,3]. Diamond has outstanding physical properties such as the highest thermal conductivity (20 W•cm-1 •K-1 at room temperature), a large critical electric field (10 MV•cm-1), a wide doping range and a high carrier mobility in both P and N type doping types. Diamond devices are also maturing, with many improvements and breakthroughs in the recent years: Deep Depletion and inversion MOSFETs [4,5], 2DHG FETs with high current and high breakdown voltage capabilities [6], JFETs, high voltage and high temperature MESFETs, Schottky, PiN and Schottky PiN diodes [1]. Nonetheless, diamond devices based on bulk diamond conduction (e.g. MOSFETs, JFETs, MESFETs, Schottky diodes) suffer from the incomplete ionization of Boron dopants at typical operating junction temperatures (e.g. 300K-400K), which increases consequently the ON state resistance of such unipolar devices. Moreover, the active area of diamond can be limited by defect density and substrate size, which limits the high-current capability of diamond power devices in a short term.