Optimization of Negative-Capacitance Vertical-Tunnel FET (NCVT-FET)

We investigate the GaAs_0.51Sb_0.49/In_0.53Ga_0.47As negative-capacitance vertical-tunnel FET (NCVT-FET) to maximize its vertical tunneling over the corner tunneling. Negative capacitance enhances vertical tunneling more significantly than corner tunneling due to the amplified vertical electric field. By TCAD optimization of the device, small ${I}_{{\mathrm {OFF}}}$ (10 pA/ $\mu \text{m}$ ) and large ${I}_{\text{ON}}$ ( $405~\mu \text{A}/\mu \text{m}$ ) at ${V}_{\text {DD}} = {0.5}$ V with 14 mV/dec sub- ${V}_{\text {t}}$ swing over 4 dec of current were obtained. Even at ${V}_{\text {DD}} ={0.1}$ V, the optimized NCVT-FET has 10 pA/ $\mu \text{m}~{I}_{\text{OFF}}$ , $5.86~\mu \text{A}/\mu \text{m}~{I}_{\text{ON}}$ ( $144\times $ higher than the nominal TFET), and ${I}_{\text{ON}}/{I}_{\text{OFF}}$ ratio of ${6} \times {10}^{{5}}$ .