SiO2/Si3N4 Electret Incorporated AlN Substrates for Partial Discharge Mitigated WBG Power Electronics

Electrets can generate electric field without an external voltage source in contrast to a typical dielectric material. Prior research on electrets demonstrates the creation and application of electrets to minimize partial discharge (PD) under repeated, steep voltage pulses. Electrets can counteract the locally concentrated high electric fields and neutralize them to prevent PD. In this study, we employed 520 nm thin SiO
2
/Si
3
N
4
coatings on ceramic substrate made of Aluminum Nitride (AlN). At temperatures as high as 180°C, we measured PD using steep square voltage pulses with slew rates as high as 131.25 V/ns. According to the findings, SiO
2
/Si
3
N
4
thin film electrets can increase partial discharge inception voltage (PDIV) and decrease PD magnitude under extreme electrical and thermal conditions.