A new analytical threshold voltage model of cylindrical gate tunnel FET (CG-TFET)

The cylindrical gate tunnel FET (CG-TFET) is one of the potential candidates for future nano-technology, as it exhibit greater scaling capability and low subthreshold swing (SS) as compared to conventional MOSFET. In this paper, a new analytical approach is proposed to extract the gate dependent threshold voltage for CG-TFET. The potential distribution and electric field distribution in the cylindrical channel has been obtained using the 2-D Poisson's equation which in turn computes the shortest tunneling distance and tunneling current. The threshold voltage is extracted using peak transconductance change method based on the saturation of tunneling barrier width. The impact of scaling of effective oxide thickness, cylindrical pillar diameter and gate length on the threshold voltage has been investigated. The consistency of the proposed model is validated with the TCAD simulated results. The present model can be a handful for the study of switching behavior of TFET.