GSE and GWE techniques to improve on (ION) current and ambipolar conduction of tunnel FET(TFET) device: A comprehensive review

Due to its versatility, metal oxide semiconductor field effect transistor (MOSFET) based devices are seeing tremendous growth in demand. To meet the demands of high speed and low power consumption, these MOS devices are continually scaling down to produce next-generation hardware. But the shot channel effects and the limitation in the minimum subthreshold swing (SS > 60 mV/Dec), stop the further scaling of the MOSFET device. The Tunnel FET (TFET) is considered as a suitable potential replacement for the MOSFET due to its unique band-to-band tunneling (BTBT) charge carrier transport and superior subthreshold characteristics (SS < 60 mV/Dec). The TFET device effectively eliminates the SCE and allows the fine scaling of the device required by the industry. However, the TFET suffers from low ON(I_ON) current and ambipolar conduction, which makes the performance hectic for the TFET device. So, researchers proposed various methods to overcome these challenges, and gate structural engineering (GSE) and gate work function engineering (GWE) are the most recommended and yield good results for TFET. In this review paper, we have performed a comparative investigation on different devices reported on these two techniques by taking various parameters of the TFET. A detailed analysis is carried out to reveal how these techniques enhance the on (Ion) current and suppress the ambipolar current of the device. Especially the impact of the change in gate structure and gate metal work function on the tunneling width of the device focused by considering the device's electrostatic. A comparative study of different TFET architectures with different electrical parameters is reported.