Significance of Overdrive Voltage in the Analysis of Short-Channel Behaviors of n-FinFET Devices

The short–channel behaviors of n–channel (electron–conducting) fin field–effect transistors (n–FinFETs) set at different threshold voltages were analyzed at different power supply voltages. Interesting observations were made by considering the on and off voltage states of the overdrive voltage instead of the gate–source voltage. Intrinsic transistor characteristics were revealed, enabling the comparison of short–channel characteristics between devices designed for different threshold voltages. Drain–induced barrier lowering (DIBL), subthreshold swing (SS), on/off current ratio,
$\text{I}_{\mathrm{ on}}/\text{I}_{\mathrm{ off}}$
, and other parameters of the devices were considered. In addition, the novel figure of merit introduced in our previous work for the evaluation of short–channel effects, which accounts for the DIBL, SS, and
$\text{I}_{\mathrm{ on}}/\text{I}_{\mathrm{ off}}$
of the devices, was also analyzed under this context. It was shown that the off–state current does not increase significantly with the increase in the supply voltage, indicating good gate control.