Analysis of InAs-Si heterojunction double-gate tunnel FETs with vertical tunneling paths

InAs-Si double-gate TFETs exploiting the two-dimensional (2D) density-of-state (DOS) switch are studied. A full-band and atomistic quantum transport simulator based on the sp³d⁵s* tight-binding model is used to solve the quantum transport problem taking into account both lateral and vertical band-to-band tunneling paths. TFETs with only vertical tunneling components are also investigated. Our findings suggest that InAs-Si 2D-2D TFETs might offer a device solution with both steep sub-thermal sub-threshold swing (SS) and high ON-current. In the best case of an extremely thin InAs-Si 2D-2D TFET the minimal swing reaches SS = 12mV/dec and the ON-current 241 A/m.