A 10-kV Large-Area 4H-SiC Power DMOSFET With Stable Subthreshold Behavior Independent of Temperature

This paper presents the development and demonstration of large-area 10-kV 4H-SiC DMOSFETs that maintain a classically stable low-leakage normally off subthreshold characteristic when operated at les200degC. This is achieved by an additional growth (epitaxial regrowth) of a thin epitaxial layer on top of already implanted p-well regions in conjunction with a N20-based gate oxidation process. Additionally, the design space of the DMOSFET structure was explored using analytical and numerical modeling together with experimental verification. The resulting 0.15-cm
²
active 0.43-cm
²
die DMOSFET with 10-kV breakdown provides I
_DS
= 8 A at a gate field of 3 MV/cm, along with a subthreshold current at V
_GS
= 0 V that decreases from 1 muA (6.7 muA/cm
²
) at 25degC to 0.4 muA (2.7 muA/cm
²
) at 200degC.