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

Abstract

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.

Polarity-Tunable Photocurrent through Band Alignment Engineering in a High-Speed WSe2/SnSe2 Diode with Large Negative Responsivity

“…Upon illumination with 532 nm light, steady state measurements show a large negative photocurrent under type-III band alignment, whereas type-II band alignment results in typically observed positive photocurrent. Temporal photocharacteristics reveal a fast response time (in microseconds) due to the ultrafast nature of carrier transport under BTBT in contrast to the slow response times (in seconds) reported in trap or adsorbate-dependent negative photoresponse studies. ,, A maximum, ultrahigh negative R of 2 × 10 4 A/W with high speed switching comprising a response time of ∼1 μs and a fall time of ∼5 μs has been realized under the tunneling regime, making this one of the best high R –high speed vdW photodetectors, with the added capability of achieving voltage-driven tunable (negative as well as positive) photoresponse.…”

Overcoming sub-threshold swing degradation in sub 10 nm technologies

“…Typically, the mechanism of conduction in source and channel regions is determined by conduction and valence band edge [2,9]. When there is no gate voltage applied, the potential barrier as described in the previous section hindered the conduction of current.…”

“…Moreover, due to the short channel effect (SCE), the condition is even worse when it comes to the nanoscale transistors. The SCE happens when shortening of the channels also reduces VTH, which makes MOSFET more challenging to reach the fundamental limit [4] [5]. To maintain high performance in power consumption, VDD and VTH should be scaled down proportionally to the channel length to prevent SCE [2].…”

A novel broken-gap chemical-bonded SiC/Ti2CO2 heterojunction with band to band tunneling: first-principles investigation

“…Therefore, the broken-gap heterojunction has a particular benefit in tunneling field effect transistors (TFETs) and photodetectors. 11,12 SiC has gained significant attention for its exceptional properties among group III-V elements (such as Al, Si, Ge, etc.) in device applications.…”

“…Therefore, the broken-gap heterojunction has a particular benefit in tunneling field effect transistors (TFETs) and photodetectors. 11,12…”