Optical Mask For Measuring An Aberration Of Beam And Method Of Measuring The Aberration Using The Same

摘要

An optical mask for use with an exposure beam includes a mask substrate adapted to be placed on a traveling path of the exposure beam. A reference pattern is formed on the mask substrate. The reference pattern is adapted to direct the exposure beam to travel in a predetermined reference direction. A comparative pattern is formed on the mask substrate. The comparative pattern is adapted to direct the exposure beam to travel in a direction inclined at a predetermined angle with respect to the reference direction.