3D Analysis of a Shallow Trench Isolated 0.25/0.25μm NMOS Transistor

This paper presents an analysis of the small geometry 3D effects, based on experimental and simulation results of shallow trench isolated transistors. The coupling between short channel and narrow channel effects is studied as a function of bias conditions. This coupling effect reduces each 2D parasitic effect in small transistors. The threshold voltage and subthreshold current of ultra small devices have a low sensitivity to the drain and substrate bias effects, due to the combined short and narrow channel effects.