Homo and hetero junctionless tunnel field effect transistors for mixed signal applications: a review

This study presents a systematic review of junctionless tunnel field effect transistor (JLTFET)-based homo- and hetero-based devices/circuits which have gained significant popularity in recent years for their performance. The divergent ranges of JLTFET-based structures are explored, and their DC/AC characteristics are discussed in detail. Basically JLTFET device exploits the advantages of both junctionless FET (JLFET) and tunnel FET (TFET) together to vanquish the major challenges that are faced by contemporary FETs. The hetero JLTFETs studied in this review uses lower band gap materials, silicon and SiXGeX-1 and high band gap material, AlGaAsat source and channel side, respectively. Also dual material gate structure in hetero JLTFET is explored for their performance improvement. Both homo and hetero structures exhibit better performance in terms of DC parameters, subthreshold slope (SS), ON-current, OFF-current and electron tunnelling rate, whereas AC parameters include unity gain cut-off frequency (f(t)), maximum oscillation frequency (f(max)), gain bandwidth product (GBW), transconductance generation factor (TGF) and delay. The silicon-on-nothing (SON) technology-based JLTFET is studied for the performance improvement by using different dielectric materials. With respect to circuit-related study, JLTFET uses SiGeN + pocket under the gate region which act as an inverter circuit with good transient and voltage transfer characteristics (VTC). For memory circuits like SRAM, JLTFET shows better performance in terms of hold static noise margin (SNM), read SNM and write SNM.