Simulation tool for proximity effects in high aspect ratio UV-lithographic patterning

In this paper, we present a simulation tool for the estimation of diffraction effects during the exposure of complex three-dimensional structures. Different levels of microstructures and substrate cause diffraction effects during the exposure which lead to a distortion of the original mask pattern. The simulation tool enables a designer to calculate intensity profiles on the resist surface and to estimate the impact of diffraction effects on the resulting resist pattern. The simulation method and the used algorithm is described in detail. Finally, an example is used to show how the tool can be used for the optimization of mask structures by adding compensation structures.