An explicit expression for surface potential at high-end of moderate inversion

There is a moderate inversion region between the weak and strong inversion regions of MOSFET operation. This region is very important for designing analog circuits. This paper presents a new explicit expression for the surface potential at the high-end of the moderate inversion, which is useful for a circuit modeling. This expression allows a new definition for the threshold voltage V/sub th/ and a model of the relation between off-current I/sub off/ and on-current I/sub on/ of MOSFETs. A source resistance R/sub s/ has large influence on I/sub on/, so that a model for R/sub s/ was newly developed. Proposed models for V/sub th/ and I/sub off/-I/sub on/ characteristics were compared with experiments. It is found that the new definition Of Vth could apply to both short- and long-channel MOSFETs. The model revealed different I/sub off/-I/sub on/ behaviors between high and low halo dose MOSFETs.