Modeling the Effect of Gate Fringing and Dopant Redistribution on the Inverse Narrow Width Effect of Narrow Channel Shallow Trench Isolated MOSFETs

This paper presents an analytical physics-based model for width dependence of threshold voltage of nano-scale MOSFETs. Shallow trench isolated MOSFETs have been considered in the 90 nm and 65 nm technology nodes. The combined effect of gate fringing field and dopant redistribution has been considered for developing the model. The trench oxide parasitic capacitance is evaluated by conformal mapping technique and is then used to determine the width-dependent threshold voltage shift. The developed model has been validated by comparing the results predicted from the derived model with experimental data, simulation data and also with a similar model available in literature. It has been demonstrated that our model predicts more correctly the inverse narrow width effect on threshold voltage of nano-scale devices compared to the existing model.