The Dual Effects of Gate Dielectric Constant in Tunnel FETs

In this paper, tunnel FETs (TFET) with different gate dielectrics are studied. The effects of gate dielectric constant in the TFET are investigated with qualitative analysis and numerical simulations. The regulation of gate-channel coupling and the modulation of electric field at the tunnel junction both contribute to the carrier tunneling in TFETs. The dominant one is determined by the topology of the channel material. A uniform high-κ gate dielectric has a detrimental effect in 2-D TFETs, in contrary to the beneficial effect in body TFETs. Thus, the dual effects should be accounted in TFETs gate dielectric optimization considering the topology of the channel material.