A novel 2-D analytical model for the electrical characteristics of a gate-all-around heterojunction tunnel field-effect transistor including depletion regions

摘要

A new two-dimensional analytical model is proposed for the electrical attributes of a gate-all-around heterojunction tunnel field-effect transistor, including the potential distribution, lateral and vertical electric fields, drain current, subthreshold swing, and threshold voltage. The potential distribution in the device is obtained by using the two-dimensional (2-D) Poisson equation, including the depletion regions across the source-channel, channel, and drain-channel regions. The drain current of the proposed device is derived by combining parameters such as the band-to-band generation rate, lateral electric field, and channel thickness as well as the shortest tunneling path in Kane's model. The threshold voltage is obtained from the second derivative of the drain current. The effects of the depletion regions are also included in the model to obtain accurate results. The results are validated against ATLAS technology computer-aided design (TCAD) simulations with the SILVACO tool, revealing excellent agreement.