4.5.3 ACCUFET

Both SiC UMOSFET and DMOSFETs suffer from surface problems such as step-bunching and non-uniform doping density [182]. Several groups have shown that incorporating an n-type counter-doped layer along the oxide/semiconductor interface restores the channel mobility in both types of transistors. One version of this structure, known as an accumulation-channel FET or ACCUFET, was demonstrated in the vertical DMOSFET geometry by Shenoy et al. [183] and in the UMOSFET geometry by Hara et al. [184].

SiC lateral DMOSFETs are attractive for monolithic integration with low voltage logic components in form of power IC; however, their design is more challenging due to the surface problems mentioned above. This section presents an ACCUFET structure for lateral DMOSFET which improves these problems. A simulation based analysis on the performance and reliability of this structure compared to the conventional device has been performed.
T. Ayalew: SiC Semiconductor Devices Technology, Modeling, and Simulation