Effect of lens aberrations as a function of illumination condition on full-field process windows

Abstract

The effect of lens aberrations on the process windows of a 248nm stepper is presented for multiple locations within the exposure field and for various illumination conditions. It is shown that the effect on the process window depends on the field location and the illumination condition. The common process window for multiple field locations is significantly reduced from the single location result. Process window data obtained with one illumination condition is shown to be useful in predicting results with other illumination conditions.