Abstract: An exposure apparatus for use in a photolithographic process, in which an illumination beam is attenuated, split by a beam splitter, and received by an integrator sensor which produces an illuminance detection signal. The illuminance detection signal and a desired illuminance signal from an exposure control system are supplied to a power supply system which powers a mercury-vapor lamp with a predetermined resolution such that the two signals may be equal to each other. The exposure control system determines any error in the illuminance on the wafer from the illuminance detection signal, and supplies a stage control system with correction values for the velocities at which a reticle stage and a wafer stage is to be moved for scanning. The light source may be powered with a constant input power, and an adjustment rod for adjusting the quantity of light of the illumination beam may be disposed in a light travelling region through which the light of the illumination beam from the light source travels.

Abstract: An exposure apparatus for transferring a pattern on a mask onto a photosensitized substrate by exposure, having an illumination optical system, a mask stage for moving the mask and a substrate stage for moving the substrate. An attenuator is disposed between the light source and the photosensitized substrate for attenuating the illumination beam with a variable attenuator rate. A controller controls the output power of the light source and attenuator of the illumination beam such that the exposure energy approaches a predetermined desired value. A stage controller controls the velocities at which the mask stage and the substrate stage are moved for scanning according to the difference between the exposure energy measured by the sensing system and the predetermined desired value.