Engineering the Electron-Hole Bilayer Tunneling Field-Effect Transistor

Abstract — The electron–hole (EH) bilayer tunneling field-effect transistor promises to eliminate heavy-doping band tails enabling a smaller subthreshold swing voltage. Nevertheless, the electrostatics of a thin structure must be optimized for gate efficiency. We analyze the tradeoff between gate efficiency versus ON-state conductance to find the optimal device design. Once the EH bilayer is optimized for a given ON-state conductance, Si, Ge, and InAs all have similar gate efficiency, around 40%–50%. Unlike Si and Ge, only the InAs case allows a manageable work function difference for EH bilayer transistor operation. Index Terms — Electron–hole (EH) bilayer, quantization, semiconductor device modeling, tunneling, tunneling field-effect transistor (TFET). I.