Rounding and taper fin effect of FinFET varactors observed using three-dimensional simulation model

The capacitance-voltage electrical characteristics of fin field-effect transistor (FinFET) varactors, which have fins with different taper angles and rounding radiuses, are investigated. By fitting the results of a three-dimensional correction simulation with those of an experimentally fabricated FinFET varactor, the two key factors of process simulations (taper angle and rounding radius r) are extracted. It is found that the capacitance of the FinFET varactor changes when the fin cross-sectional profile varies. The examination presented here is useful in the fabrication of FinFETs. It clarifies the fin cross-sectional profile effect on the FinFET varactor capacitance.