Scanning exposure in which an object and pulsed light are moved relatively, exposing a substrate by projecting a pattern on a mask onto the substrate with pulsed light from a light source, light sources therefor, and methods of manufacturing

Abstract

In a scanning exposure apparatus and method, a pattern formed on a mask is transferred onto a substrate by scanning the mask and the substrate synchronously with respect to pulsed light emitted from a pulsed laser light source. A number of pulses of a light beam that are to be emitted to each point on the substrate during scanning exposure is determined, and the light source is controlled according to the determined number of pulses, so that the maximum scanning speeds of the mask and the substrate and/or the maximum oscillation period of the pulsed light are maintained during the scanning exposure process. In another arrangement, during the process of exposing a shot area on the substrate, integral values of the amount of exposure energy are detected at a plurality of points in that shot area. Based on this detection result, the oscillation frequency of the pulsed light that is to be emitted to the next shot area is determined so that the next shot area is exposed at an appropriate exposure level. In another arrangement, the light source and/or the exposure light emitted from the light source are adjusted so that the output level of the light source is set to the minimum required level, and so that the target value of the integral exposure dose is reliably achieved without reducing the scanning speeds of the mask and the substrate from their maximum. In still another arrangement, during the process for exposing the substrate to the laser beam, while scanning the substrate to transfer the mask pattern, the illuminance of the light source is controlled at a constant value. In yet another arrangement, when the exposure apparatus is not performing exposure (i.e., during the non-exposure period of the operation), the illuminance of the light source is maintained at a constant level, but the exposure light is blocked by a blind so as not to reach the mask or the mask stage.