Hybrid illumination system for use in photolithography

摘要

An illumination system comprising: an illumination source (10) generating a beam of electromagnetic radiation; a multi-image optical element (14) receiving the beam of electromagnetic radiation from said illumination source, said multi-image optical element (14) having a first numerical aperture (); and an array optical element (18) receiving the beam of electromagnetic radiation from said multi-image optical element (14) and providing an emerging predetermined angular distribution of electromagnetic radiation, said array optical element (18) having a second numerical aperture ( alpha 2), the second numerical aperture being larger than the first numerical aperture; whereby electromagnetic radiation from said illumination source (10) forms an illumination field for projecting an image of a reticle (26).