4.5.2 DMOSFET

All the trench problems mentioned above are avoided by the planar DMOS geometry [180]. A cross-section of the DMOSFET structure is provided in Fig. 4.23. In silicon the p-well and the n+ source regions of DMOSFETs are formed by double diffusion of p- and n-type dopants through a single oxide implantation and high temperature implant activation (the name for this device is derived from this double-diffusion process), but this process is impractical in SiC due to the small diffusion coefficients for impurities in the material.
T. Ayalew: SiC Semiconductor Devices Technology, Modeling, and Simulation