Improved analytical model of surface potential with modified boundary conditions for double gate tunnel FETs

In this paper, an improved analytical model of the channel surface potential in the tunnel field effect transistors is established with modified boundary conditions considering the source and drain depletion widths, avoiding the deviation of the channel potential and the overestimate on the electric field. Based on the proposed surface potential model, the threshold voltage model is also developed with the transconductance change method. The influences of the channel and oxide structures on surface potential and threshold voltage are investigated. The good agreement is obtained by the comparison of the modeling results with the numerical simulation results, verifying the validation of the proposed model, and it also implied that this model will be helpful for the further investigation of TFETs.