Lithographic apparatus

摘要

A lithographic projection apparatus having a masking device (MD) for obscuring part of at least one of a patterning means (MA) used for patterning a projection beam before imaging the patterned beam onto a substrate. The masking device (MD) includes a first masking means (4) to obscure said part of said patterning means (MA) in a first direction (Y) and a second masking means (6) to obscure said part in a second different direction (X), wherein said first and second masking means are disposed in the vicinity of said focal plane in a mechanically uncoupled arrangement with respect to each other. <IMAGE>