RIGOROUS 3-DIMENSIONAL PHOTORESIST EXPOSURE AND DEVELOPMENT SIMULATION OVER NONPLANAR TOPOGRAPHY

A rigorous three-dimensional (3-D) simulation method for photoresist e xposure and development is presented in which light scattering due to a nonplanar topography is calculated using the Maxwell equations. The method relies on a Fourier. expansion of the electromagnetic field and extends the two-dimensional (2-D) differential method [1], [2] to the third dimension. The model accounts for partial coherent illumination and considers the nonlinear bleaching reaction of the photoresist, Fo r the development process, the cellular-based topography simulator of [3] has been extended. A detailed description of the theory behind the simulation method is presented, the computational efficiency is discu ssed, and simulation results are given.