A Compact Model for Double-Gate Heterojunction Tunnel FETs

A compact model for generic heterojunction tunnel FETs (H-TFET) is developed to simulate H-TFET formed by different source/body material systems. The model is based on the device electrostatic potentials obtained from the solution of Poisson's equation. After deriving the potential profile, the tunneling distance from the source to the channel is calculated by matching the boundary conditions between the two materials. The drain current, terminal charges, and capacitance are derived based on the electrostatics dictated by the tunneling distance. To improve the accuracy for lightly doped source H-TFET in p-type devices, the effect of source depletion is also included. The model has been implemented in a circuit simulator without convergence program. It has also been extensively verified by TCAD simulations and published data to show its validity.