Investigation of Noise Characteristics in Gate-Source Overlap Tunnel Field-Effect Transistor

The analog circuit performance of tunnel field-effect-transistor (TFET) can be improved by implementing the concept of gate-source overlap. This paper investigates the impact of variation in gate-source overlap length on ON current, leakage current, capacitance and noise spectral density. Further the analysis has been carried out by excluding and including the effect of Gaussian traps. As the gate fully overlaps the source region a high ON current of 2.42*10−4 A/μm, low leakage current of 9.61*10−12 A/μm, ION/IOFF ratio of 108, sub-threshold slope (SS) of 37 mV/dec are obtained. The optimised gate-source overlap length is 60 nm as it shows good electrostatic control and the maximum value of ON-current is achieved but the noise spectral density slightly increases for fully overlapped gate-source region.