Fig. 1. Cross section of device structure of normal PNN TFET based on FD-GeOI.

Fig. 2. Cross-section of two tunneling paths (TTP) TFET based on PD-GeOI substrate.

Fig. 3. Computed energy-band diagrams of TTP TFET for both off-state (solid line, |V_DS| = 1 V, V_GS = 0 V) and on-state (dashed line, |V_DS| = 1 V, V_GS = 1 V) along (a) line tunneling path 1 and (b) line tunneling path 2.

Fig. 4. Transfer characteristics of FD-GOI TFET and proposed TTP TFET.

Fig. 5. Composition of current of the proposed TTP TFET.

Fig. 6. Transfer characteristics of TTP TFET for different lengths of buried layer L_BP.

Fig. 7. Distributions of surface electron density along x axis of TTP TFET for different values of L_BP at V_GS = 1 V and V_DS = 1 V.

Fig. 8. Point tunneling width when L_BP = 50 nm and 100 nm at V_GS = 0 V and V_DS = 1 V.

Fig. 9. Band bending from channel to LDR along x axis at the upper right-hand corner of the buried layer for (a) off-state at V_DS = 1 V, V_GS = 0 V and (b) on-state at V_DS = 1 V, V_GS = 1 V.

Fig. 10. Transfer characteristics of TTP TFET for different doping concentrations of slightly doped region (N_LDR).

Fig. 11. Plots of optimized performance of TTP TFET for L_BP = 50 nm, 250 nm, 450 nm, and 650 nm at L_gap = 50 nm.

Fig. 12. Output characteristics of TTP TFET.