PHOTO STABILIZING APPARATUS FOR DETECTION OF A SEMICONDUCTOR SUBSTRATE

摘要

A photo stabilizing apparatus for detection of a semiconductor substrate is provided to compensate for loss of main beams with adjusting beams whose intensity is controlled by a light intensity control member. A photo stabilizing apparatus for detection of a semiconductor substrate comprises a beam splitter(110), a plurality of mirrors(122~126), and a light intensity control member(130). The beam splitter splits beams provided to the substrate into a main beam progressing in a first path and an adjusting beam progressing in a second path. The mirror reflects the main beam and adjusting beam many times and guides the beams to the substrate. The light intensity control member is installed between the mirrors on the second path, adjusts intensity of the adjusting beam to compensate for loss of the main beams.