Modeling intrinsic and extrinsic asymmetry of 3D cylindrical gate/gate-all-around FETs for circuit simulations

In a vertical cylindrical gate transistor, we identify doping gradation along channel and structural difference in electrode regions as major reasons for highly asymmetric drain current characteristics. These effects have been captured in a physical manner in a SPICE model. Calibration results of such a model to silicon device data from a vertical cylindrical gate technology that exhibits asymmetric I-V characteristics is presented for the first time.