We present a rigorous, three-dimensional model for the simulation of resist
exposure and development. The development simulation is based on a cellula
r surface movement algorithm and benchmarked for several prototypical test
cases. Exposure simulation is performed by an extension of the two-dimensio
nal differential method to three dimensions. This method relies on a Fourie
r expansion of the electromagnetic (EM) field in the lateral coordinates. W
e demonstrate simulation examples for exposure and development over a plana
r substrate, a dielectric and a reflective step.