Vertical Tunnel Field Effect Transistors (VTFETs): A Potential Candidate for Low Power Applications

Today’s era is largely depends upon Internet-of-things (IOT) and neuromorphic computing. For these low power electronics is required. The life of human is largely improved by the use of the IOT devices. Most of the IOT systems relies upon low power for security of hardware structure. As demand for IOTs is increasing day-by-day, it requires high energy efficient design for the electronics industry in future. The tunnel field-effect transistors (TFETs) are emerged as a great research interest among the researchers. In normal Metal-Oxide-Semiconductor Field-Effect-Transistor (MOSFET), the minimum achievable limit of the Subthreshold Swing (SS) is limited to 60 milli-volt/decade. The TFETs can achieve very low SS below than the fundamental limit of 60 milli-volt /decade. TFETs can also achieve very low off state current (I
OFF
) which is applicable for low-power application in the IOT and neuromorphic computing. The current conduction in a TFET depends on quantum mechanical tunneling rather than thermionic emission which is in case of MOSFET. This article, reviews the performance of vertical TFETs (VTFETs) which are suited for low-power and low-voltage digital circuit applications. The performance of GaSb/Si VTFET with a source pocket, Negative-capacitance VTFET, Ferroelectric L-patterned gate TFET (FL-TFET), Ge-Source VTFET With Delta-Doped Layer, Ge-source VTFET with a field-enhanced high-k layer (FEHL-VTFET) are studied. The various VTFETs are compared in terms of DC parameters, such as I
ON,
I
OFF,
ratio of I
ON
to I
OFF
and avg. SS. NCVT-FET serves as a performance booster among the VTFETs in terms of low SS, but suffers from low I
ON
to I
OFF
ratio. GaSb/Si VTFET with a source pocket has high current ratio among all the discussed VTFETs.