A novel SiC high-k superjunction power MOSFET integrated Schottky barrier diode with improved forward and reverse performance

A new SiC superjunction power MOSFET device using high-k insulator and p-type pillar with an integrated Schottky barrier diode(Hk-SJ-SBD MOSFET)is proposed,and has been compared with the SiC high-k MOSFET(Hk MOSFET),SiC superjuction MOSFET(SJ MOSFET)and the conventional SiC MOSFET in this article.In the proposed SiC Hk-SJ-SBD MOSFET,under the combined action of the p-type region and the Hk dielectric layer in the drift region,the concentration of the N-drift region and the current spreading layer can be increased to achieve an ultra-low specific on-resistance(Ron,sp).The integrated Schottky barrier diode(SBD)also greatly improves the reverse recovery performance of the device.TCAD simulation results indicate that the Ron,sp of the proposed SiC Hk-SJ-SBD MOSFET is 0.67 mΩ·cm^(2)with a 2240 V breakdown voltage(BV),which is more than 72.4%,23%,5.6%lower than that of the conventional SiC MOSFET,Hk SiC MOSFET and SJ SiC MOSFET with the 1950,2220,and 2220V BV,respectively.The reverse recovery time and reverse recovery charge of the proposed MOSFET is 16 ns and18 nC,which are greatly reduced by more than 74%and 94%in comparison with those of all the conventional SiC MOSFET,Hk SiC MOSFET and SJ SiC MOSFET,due to the integrated SBD in the proposed MOSFET.And the trade-off relationship between the Ron,sp and the BV is also significantly improved compared with that of the conventional MOSFET,Hk MOSFET and SJ MOSFET as well as the MOSFETs in other previous literature,respectively.In addition,compared with conventional SJ SiC MOSFET,the proposed SiC MOSFET has better immunity to charge imbalance,which may bring great application prospects.

Time-domain and Frequency-domain Analyses of PETT Oscillation in Press Pack IGBTs

Plasma extraction transit time(PETT)oscillation might appear in IGBT devices,which is harmful to the electromagnetic compatibility(EMC)of a renewable energy system.To eliminate this oscillation,its frequency-domain characteristics in wire-bonded IGBT devices have been extensively studied.However,the time-domain analysis of PETT oscillation,especially in Press Pack IGBT(PPI)devices,has not attracted enough attention yet.In this paper,PETT oscillations with multi-chips in PPI devices are systematically investigated by experiments.It is first reported there are multiple resonant oscillations at the tail period when multi-chips turn off.Oscillations overlap in the time domain waveforms,which lead PETT oscillation to be more serious in multi-chips.Then,PETT oscillation is divided into three different feedback states for the first time.For the IGBT chip in the PETT oscillation,its physical based model and behavior model are proposed,which further form the equivalent circuit as the two-port network.Moreover,it is indicated that only parallel resonances can lead to PETT oscillation,which is consistent with experiment results.