Analytical modeling of surface potential, capacitance and drain current of heterojunction TFET

Abstract

This paper presents an analytical model for double-gate (DG) Heterojunction Tunnel Field Effect Transistor (H-TFET). The Poisson’s equation is solved to obtain the electrostatic potential solution which is used to drive the capacitance and drain current model. To include the impact of n-type impurity atoms in the channel region, Poisson’s equation considers the accumulation charges and ionized charges. Similarly, these charges are considered for capacitance modeling. Different III–V materials along with group-IV materials are being used to enhance the performance of H-TFET. The proposed model includes the impact of off-set between the bands due to the formation of heterojunction at the tunneling interface. The model also incorporates the influence of both the gate and the drain voltages, simultaneously. To ensure the performance of the developed model, the modeled results are validated with TCAD simulation results and a good match is obtained between them. In addition, the developed model does not include any implicit function making it SPICE-friendly for circuit designing.