MO Exposure Optics (MOEO), is a novel mask aligner illumination system for all SUSS MicroTec Mask Aligners. Self-calibrating light source (no lamp alignment after lamp exchange), improved light uniformity, telecentric illumination and the possibility of freely shaping the angular spectrum are main advantages. Full control of the illumination allows to reduce diffraction effects, enhance resolution, improve CD uniformity and yield. It is now possible to fully simulate the lithography process by using LAB software from GenISys. Well known lithography techniques like customized illumination, optical proximity correction (OPC) and source-mask optimization (SMO) are now available for mask aligner lithography. Mask aligner lithography has entered a new era.