Lithographic projection apparatus and device manufacturing method

摘要

A lithographic apparatus of the scanning type in which reticle masking blades 7 are opened at the beginning of a scan. Means are provided to compensate for an increase in the intensity density of the illumination beam as the reticle masking blades are opened. These means may comprise lamp control means 10 for controlling a compensating decrease in the lamp intensity. The reticle masking blades 70 may be manufactured of, e.g., quartz and provided with a reflective rear coating, e.g. of aluminium, so that portions of the illumination beam intercepted by the reticle masking blades are totally internally reflected. <IMAGE>