Effect of band to band tunnelling (BTBT) on multi-gate Tunnel field effect transistors (TFETs)-A Review

TFETs (tunnel field effect transistor) are providing solution to affairs associated with conventional MOSFET devices such as short-channel effects (SCEs) and limitation of minimum (60 mV/decade) subthreshold slope (SS). TFET is a p-i-n diode which conducts in reverse bias and behaves like a transistor due to tunnelling mechanism of the charge carriers across the barrier called band-to-band tunnelling (BTBT). TFETs face some critical problems like lower ON-state currents and ambipolar behaviour of conduction currents. The purpose of this review is to study a highly efficient TFET which provides significant improvements in ION/IOFF ratio with improved ON state current and ambipolar current suppression to enhance the performance of the device. TFET with multigate structure will be studied by using different dielectric and substrate materials. TFET may be considered as promising candidate over MOSFETs in low-power and high-speed switching circuits.