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A 3D planar pseudo-vector approach to modeling resist exposure has been implemented for optical projection lithography. The approach allows for high numeric aperture effects revealed by others in the resist latent images; comparisons made show its fine agreement with rigorous vector modeling up to NA value of 0.7. Fast Fourier transform technique has been applied to reduce mask and resist (including postbake) modeling runtime; the effects of finite accuracy approximations of the mask areas and mask periodicity have been investigated and compensated. The overall performance of the exposure model has been optimized to be 10X faster than for a similar vertical propagation model. A modified `cell' algorithm has also been used to model resist development; this resulted in more accurate resist profiles for the same latent image accuracy, providing additional runtime savings to resist profile simulations.

We present a description of a software tool and a methodology for easily creating photoresist development rate parameters in lithography simulation. The tool optimizes parameters using the Modified Simplex Method. The methodology uses the tool to provide insight into the effects of the development rate parameters and to find usable parameters quickly. The reasonings behind the methodology are discussed as well as advantages and disadvantages. Results from three different lithography simulators are shown to agree well with experimental cross-section SEM data.