Sub-threshold behavior of long channel undoped cylindrical surrounding-gate MOSFETs

This paper reported the sub-threshold behavior of long channel undoped surrounding-gate (SRG) MOSFETs with respect to body radius. Based on a rigorous channel potential model presented in this work, the ideal room temperature subthreshold slope of 60 mV/dec can only be achieved when the silicon body radius is smaller than a critical value. With larger silicon body radius, SRG MOSFETs display a dual subthreshold slope of 60 mV/dec and 120 mV/dec. Based on the complex subthreshold characteristics, a new definition of threshold voltage together with an extraction method is adopted to investigate threshold voltage characteristics of undoped SRG MOSFETs in this paper.