A static image distortion characteristic is averaged in the width of a projection area in a scanning direction and becomes a dynamic image distortion characteristic, when a mask pattern is scan-exposed onto a photosensitized substrate by a projection exposure apparatus. At least a random component included...http://www.google.com.au/patents/US6522386?utm_source=gb-gplus-sharePatent US6522386 - Exposure apparatus having projection optical system with aberration correction element
