Analytical modelling design and simulation of reconfigurable tunnel field effect transistors

Abstract

As the device dimensions are scaled down, low power consumption and high-speed newlineoperation are becoming a major concern in conventional metal oxide semiconductor newline newlinefield effect transistor (MOSFET) based very large-scale integration (VLSI) tech- newlinenology. Increasing power density during miniaturisation is a severe bottleneck in newline newlineMOSFETs due to thermally limited subthreshold swing (SS) of 60 mV/decade. These newlinescaling limitations imply the need for alternative devices at nanometre dimensions. newlineA tunnel field effect transistor (TFET) is considered as one of the promising devices newlineto replace the MOSFET due to its weak temperature dependence on SS, ultra-low newlineoff-state current and low power operation. TFET enables a high-speed transition newlinefrom off-state to on-state because of its small SS. The band to band tunneling (BTBT) newlinein TFET offers sub-60 mV/decade SS, which is not attainable with conventional newlineMOSFET. newline newlineAn analytical model for a device provides a better understanding of the phys- newlineical phenomena behind the device operation. One of the advantages of analytical newline newlinemodelling is its computational simplicity. A final analytical expression of a device newlineis developed by combining well-known physics based models, theories behind the newlineoperation, assumptions and approximations. In this work, an analytical model for newlinepotential and current of a doped channel TFET by considering accumulation and newlineinversion charge carriers is proposed. The model is derived for a homo-junction, newlinesingle gated n-type TFET (nTFET) by solving two-dimensional (2D) Poission s newlineequation. The proposed model is compared with technology computer-aided design newline(TCAD) simulations. Variation of potential in the channel region of an nTFET for newlinedifferent device dimensions and doping profiles are studied using the proposed model. newline