Patent ID: 6744492
Filing Date: 2004-06-01
Classification: G03F

Abstract:
An exposure apparatus comprising:a light source of a pulsed laser; an illumination optical system illuminating an original on which a pattern is formed by exposure light emitted from said light source; a projection optical system projecting the pattern to a photosensitive object; a first photodetector disposed in a portion for receiving light from an optical path between said light source and a portion where the original is placed, said first photodetector being used for monitoring an emission light amount from said light source; and a processing system performing sensitivity correction of said first photodetector relative to information of a pulse energy of the light source, an oscillation frequency of the light source, a time of irradiating a pulsed laser light to said illumination optical system in said oscillation frequency, and a time when the pulsed laser light is not irradiated to said illumination optical system and is longer than a pulse period of said oscillation frequency.