SUMMARY We propose a new inverse modeling method to extract 2D channel dopant profile in an MOSFET. The profile is extracted from threshold voltage (Vth) of MOSFETs with a series ofgate lengths. The uniqueness ofthe extracted chan- nel and drain profile is confirmed through test simulations. The extracted profile ofactual 0.1 µm nMOSFETs explains reverse short channel effects (RSCE) ofthreshold voltage dependent on gate length including substrate bias dependence.