摘要 |
An apparatus has a pulse light source for emitting light pulses with varying light quantities, an illumination optical system for radiating the light pulses from the source onto a predetermined illumination region on a mask on which a transfer pattern is formed, and a projection optical system for projecting an image of the pattern onto a predetermined exposure region on a substrate, and which synchronously scans the mask and the substrate during the projection. The apparatus includes a measuring device for detecting intensities of the light pulses radiated onto the substrate during the scanning and measuring an integrated light quantity on each of a plurality of partial regions in the exposure region on the substrate on the basis of a detection signal of the intensities, wherein the partial regions are defined by a scanning speed of the photosensitive substrate and an oscillation interval of the light pulses. The apparatus further includes an adjusting device for adjusting an intensity of the next light pulse to be radiated onto the mask on the basis of a difference between a target integrated light quantity and the measured integrated light quantity on each of the partial regions when some light pulses are radiated onto the mask.
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