Novel Short-Circuit Failure Mechanisms of Trench SiC MOSFETs Suffering Total Ionizing Dose
Student Contest:
No
Affiliation Type:
Academia
Keywords:
Trench SiC MOSFETs, TID effect, short-circuit, mechanisms, hole capture.
Abstract:
This work reveals how total-ionizing-dose (TID) irradiation influences the short-circuit (SC) failure mechanism of double-trench silicon carbide (SiC) metal-oxide-semiconductor field-effect transistors (MOSFETs). The 400V, 600V, and 800V SC experiments are carried out, suffering 500krad Co-60 TID with multiple gate-bias conditions: DC+ (15V), DC− (−5V), and bipolar AC (15/−5V). The unirradiated devices show a gate-source failure, whereas irradiated ones show three-terminal failure. The failure mechanism is that irradiation-induced hole capture weakens the gate oxide and increase the peak drain-source current, which is verified by the evolution of threshold voltage (VTH), on-state resistance (RDS(ON)), input capacitance–gate voltage (CISS-VG) curves. Finally, a band diagram is used to explain hole-capture process, which provides a physical insight. The results provide a practical guideline for short-circuit reliability design of SiC MOSFETs in space environments.
