In this paper, we review the performance, reliability, and robustness of the current 4H-SiC power DMOSFETs. Due to advances in device and materials technology, high power, large area 4H-SiC power DMOSFETs (1200 V, 67 A and 3000 V, 30 A) can be fabricated with reasonable yields. The availability of large area devices has enabled the demonstration of the first MW class, all SiC power modules. Evaluations of 1200 V 4H-SiC DMOSFETs showed that the devices offer avalanche power exceeding those of commercially available silicon power MOSFETs, and have the sufficient short circuit robustness required in most motor drive applications. A recent TDDB study showed that the gate oxides in 4H-SiC MOSFETs have good reliability, with a 100-year lifetime at 375oC if Eox is limited to 3.9 MV/cm. Future work on MOS reliability should be focused on Vth shifts, instead of catastrophic failures of gate oxides.

4H-SiC Bipolar Junction Transistors (BJTs) and hybrid Darlington Transistors with 10 kV/10 A capability have been demonstrated for the first time. The SiC BJT (chip size: 0.75 cm2 with an active area of 0.336 cm2) conducts a collector current of 10 A (~ 30 A/cm2) with a forward voltage drop of 4.0 V (forced current gain βforced: 20) corresponding to a specific on-resistance of ~ 130 mΩ•cm2 at 25°C. The DC current gain, β, at a collector voltage of 15 V is measured to be 28 at a base current of 1 A. Both open emitter breakdown voltage (BVCBO) and open base breakdown voltage (BVCEO) of ~10 kV have been achieved. The 10 kV SiC Darlington transistor pair consists of a 10 A SiC BJT as the output device and a 1 A SiC BJT as the driver. The forward voltage drop of 4.5 V is measured at 10 A of collector current. The DC forced current gain at the collector voltage of 5.0 V was measured to be 440 at room temperature.

A new MOSFET structure named the CIMOSFET (Central Implant MOSFET) has been presented and experimentally confirmed on SiC. The novelty of the CIMOSFET lies in a p-type implant introduced in the middle of the JFET area to shield the oxide interface field from the drain bias. Compared to the commercially available 1200 V SiC DMOSFET, this new concept has significantly reduced the on-resistance (Ron) and gate-drain capacitance (Cgd) simultaneously, produced a record low Ron·Qgd Figure of Merit of 455 mΩ·nC at 25°C, and 700 mΩ·nC at 150°C (~30% of the best data found). Only a 55% increase in Ron from 25°C to 150°C has been achieved due to the highly doped drift layer used on the CIMOSFET. Inductive load switching measurements have shown the CIMOSFET exhibits a fast switching performance. The CIMOSFET blocks 1600 V even though its drift doping is higher than that of the conventional DMOSFETs.

SiC IGBTs are suitable for high power, high temperature applications. For the first time, the design and fabrication of 9 kV planar p-IGBTs on 4H-SiC are reported in this paper. A differential on-resistance of ~ 88 m(cm2 at a gate bias of –20 V is achieved at 25°C, and decreases to ~24.8 m(cm2 at 200°C. The device exhibits a blocking voltage of 9 kV with a leakage current density of 0.1 mA/cm2. The hole channel mobility is 6.5 cm2/V-s at room temperature with a threshold voltage of –6.5 V resulting in enhanced conduction capability. Inductive switching tests have shown that IGBTs feature fast switching capability at both room and elevated temperatures.

The effects of Shockley stacking faults (SSFs) that originate from half loop arrays (HLAs) on the forward voltage and reverse leakage were measured in 10 kV 4H-SiC PiN diodes. The presence of HLAs and basal plane dislocations in each diode in a wafer was determined by ultraviolet photoluminescence imaging of the wafer before device fabrication. The SSFs were expanded by electrical stressing under forward bias of 30 A/cm2, and contracted by annealing at 550 °C. The electrical stress increased both the forward voltage and reverse leakage. Annealing returned the forward voltage and reverse leakage to nearly their original behavior. The details of SSF expansion and contraction from a HLA and the effects on the electrical behavior of the PiN diodes are discussed.