Influence of Fringing-Field on DC/AC Characteristics of SiGe Based Multi-Channel Tunnel FETs

Abstract

Tunnel field-effect transistors (TFETs) are the decent performance estimators in the prospective of short-channel effects. In such structures, a small inter-gate separation (IGS) is a key factor that appraises for high packed-density with more number of channels (N) to deliver superior performance. Hence, the investigation is majorly focused on scaling IGS and its fringing-field impact on device behavior for the first time. The outcomes reveal that the high fringing-field initiates for IGS < 10 nm and influences the tunneling probability and scattering strongly at 1-nm IGS, which affect the DC and RF characteristics; hence, optimized values of IGS are investigated and determined as IGS > 10 nm. The results state that the optimized IGS can provide source to deliver high ratio of on-and off-current (Ion/Ioff). Even though, a small IGS is beneficial for reduction in the total capacitance, the RF performance improvement depends on a large IGS. The investigation is further extended and quantified for the finest IGS in multi-channel TFETs when N varies from 1 to 10. These analyses are assessed for the emerging technological nodes.