Analytical Modelling and Simulation of Drain Doping Engineered Splitted Drain Structured TFET and its Improved Performance in Subduing Ambipolar Effect

The study presents an analytical model for the potential distribution of a drain doping engineered 2D tunnelling field effect transistor (TFET) with splitted drain structure. Hence, tunnelling drain current is derived using this potential distribution. Further, the study analyses the influence of drain doping engineering on all characteristics and parameters of a TFET model. Splitted drain structure exhibits major reduction in ambipolar conduction due to increase of the tunnelling width at the channel-drain junction. Simulation of four different structures of the device consisting of splitted drain region with relative location and doping concentration is executed. The structures are named according to the relative position of the drain: splitted-drain single-gate TFET (SD-SG TFET: total drain is splitted), top-splitted-drain single-gate TFET (TSD-SG TFET: splitted-drain in upper location), Mesial-splitted-drain single-gate TFET (MSD-SG TFET: splitted-drain in middle location), and basal-splitted-drain single-gate TFET (BSD-SG TFET: splitted-drain in bottom location). All the fundamental device characteristics and parameters are analysed for all the four structures, and their merits and drawback are recorded for optimal valuation and detection of better structure. All the proposed structures show improved performance with suppressed gate leakage and ambipolarity than conventional planar TFET. All the simulations are done in Silvaco, Atlas.