Implementation of a Boolean function with a double-gate vertical TFET (DGVTFET) using numerical simulations

Tunnel field-effect transistors (TFETs) have been explored extensively as a possible substitute for MOSFETs, especially for digital system design applications. Unlike conventional MOSFET devices, TFETs exhibit certain unique characteristics which are suitable for energy-efficient digital system design. In this paper, we report the use of a single device with both terminals biased independently for basic two-input Boolean logic operations AND, OR, NAND, and NOR using technology computer-aided design (TCAD) simulations. It is shown that these basic Boolean operations can be realized by minimally altering the design of a double-gate vertical TFET (DGVTFET) device and by selecting the appropriate device characteristics. The results show that when the Boolean functions are implemented, the I_ON/I_OFF ratio is in the range of 10⁹ to 10¹³ at a supply voltage V_DD = 1 V. Simulation results show that the use of a gate–source overlap technique and the selection of a suitable silicon body thickness are vital to obtaining distinct logic functions using a DGVTFET.