The improvement of I-V characteristics curve fitting by the modification of SPICE model-level 3

The semi-empirical SPICE model-level 3 is obviously improved by treating the effective electrical channel length L_eff and source-drain external resistance R_SD as bias-dependent in the lightly-doped-drain MOSFET devices. The universal surface mobility model: μ_s=μ₀/(1+θ(V_GS-V_TH )) is proved again, i.e., the parameters θ and μ₀ are the same for different channel length devices. On the other hand, the saturation velocity υ_s is treated as an empirical parameter. Through these improvements: bias-dependent L_eff, R_SD, and remodeled υ_s, the model becomes more suitable to fit the I-V characteristics of devices with large range of device channel length using a single set of device parameters