Subthreshold Drain current hysteresis of planar SiC MOSFETs
Résumé
4H-SiC MOSFETs are available in the market as discrete devices or power modules. These devices
present many advantages for power conversion compared to Si IGBTs but still suffer from some
(reliability) drawbacks [1-3]. The Vth instability of SiC MOSFETs is topic that mainly focuses on
permanent drift of the Vth. Recoverable enhancement of the drain current in the subthreshold domain
has been pointed out formerly for SiC MOSFETs [4] and is becoming a trending topic since it may
affect the device stability. This phenomenon is not completely unknown since it affects Si devices as ell
[5], but the Wide Band Gap of SiC enhances this effect and can produce a shift of the Vth up to several
volts. As a matter of fact, hysteresis can make the devices switch faster, which could be an advantage
to normal operation, but it can also make the devices switch on at lower gate bias, thus making them
prone to undesired switching and leading to short circuit failure. Another problem can arise in the case
of short-circuit, since the drain current will attain higher values and thus putting the device to higher
thermal stress.
Domaines
Energie électriqueOrigine | Fichiers produits par l'(les) auteur(s) |
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