Subthreshold Drain current hysteresis of planar SiC MOSFETs

Besar Asllani (1, 2, 3) , A Castellazzi (2) , Dominique Planson (1, 3) , Hervé Morel (1, 3)

1 EE - Ampère, Département Energie Electrique
2 Power Electronics Machines and Control (PEMC) Group
3 INSA Lyon - Institut National des Sciences Appliquées de Lyon

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.

Mots clés: device robustness

Domaines: Energie électrique

Besar Asllani, A Castellazzi, Dominique Planson, Hervé Morel. Subthreshold Drain current hysteresis of planar SiC MOSFETs. ECSCRM'18, Sep 2018, Birmingham, United Kingdom. pp.TU.O4a.04. ⟨hal-02428531⟩