Analysis of Current Fluctuation Due to Trap and Percolation Path in Nano-Scale Bulk FinFET

An electron in the channel can be trapped into the trap inside gate oxide and detrapped into the channel, resulting in the fluctuation in drain current. To investigate the drain current fluctuation (ΔI(D)) caused by trapping/detrapping of an electron in 22 nm bulk FinFET, 3-D device simulation was performed extensively. The ΔI(D) is changed by changing the position of the trap in the gate oxide along the surface of fin body. In the bulk FinFET, the trap located near the center of side surface of the fin body gives the larger ΔI(D) compared to those of the traps located at the top center, top corner, and side bottom. At a fixed trap position, the shallower trap depth (x(T)) from the interface between the gate oxide and the fin body gives the lager ΔI(D). With decreasing fin width (W(fin)) and fin height (H(fin)), the ΔI(D) increases. Especially, decreasing H(fin) increases ΔI(D) significantly. As the trap is close to a percolation path, the ΔI(D) also increases.