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_th and a model of the relation between off-current I_off and on-current I_on of MOSFETs. A source resistance R_s has large influence on I_on, so that a model for R_s was newly developed. Proposed models for V_th and I_off-I_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_off-I_on behaviors between high and low halo dose MOSFETs