SIMULATION OF PROJECTION OPTIC LITHOGRAPHY IMAGES WITH FINITE IMPULSE-RESPONSE FILTERS

Finite impulse response (FIR) filters are used to simulate projection optic lithography images. For large arbitrary arrays of imaging data, the FIR filter simulation approach has advantages that lead to dramatic improvements in computation times. The transmission cross-coefficient (TCC) transfer function is more easily computed, the forward and reverse complex Fourier transforms need not be computed, and, foremost, the application of the TCC can be greatly simplified. Comparisons between FIR and Fourier transform simulation methods for one-dimensional objects in many cases show excellent agreement to within 1% of the total illumination intensity. The computation of projection optic images for 1000X1000 pixel arrays objects in real time ( <30 ms) appears possible using massively parallel, single-instruction multiple data computers. This capability provides a powerful design, layout, and design rule checking tool for phase-shift masks.