SIMULATING METHOD FOR PROJECTION IMAGE OF MASK PATTERN

摘要

PURPOSE:To improve the accuracy of predicting the two-dimensional light intensity distribution on a wafer by introducing a stage for calculating ray traces which calculates the routes of the rays progressing in the illuminating optical system of a reduction stepper. CONSTITUTION:The light emitted from an integrator 14 acts as a panel light source and the panel light source limited in region by a diaphragm 15 images the pattern on a reticule 17 by a condenser lens 16 onto an incident pupil surface 19 of a reduction projection lens 18 for imaging on the wafer 20. An arc 12 is handled as the assemblage of the spot light sources 24 having different light intensities and the routes up to point where the rays 25 emitted from the respective spot light sources 24 arrive at the outlet surface of the integrator 14 are determined by the calculation of the ray traces. The projected image of the reticule pattern can be calculated by taking the actual constitution of the illuminating optical system of the reduction stepper into consideration in this way and, therefore, the simulation of high accuracy is possible.