Impact of gate dielectric constant variation on tunnel field-effect transistors (TFETs)

The influence of gate dielectric constant variation on tunnel field-effect transistors (TFETs) has been investigated. High-κ materials in polycrystalline nature induce localized gate dielectric constant variation. According to the simulation results, TFETs show larger standard deviation of threshold voltage (Vth), subthreshold swing (SS) and saturation current (Id,sat) than metal-oxide-semiconductor FETs (MOSFETs). It has been revealed that local gate dielectric constant variation should be considered to evaluate the total variation of TFETs. This is because the gate insulator near the source region dominates TFET performance. Also, the ideas have been proposed in order to reduce the gate dielectric constant variation.