Patent ID: 8049864

Claim:
A device manufacturing method for projecting a patterned beam of radiation onto a substrate, comprising: in a measurement phase: steering different parts of a radiation beam individually into different directions to form a first conditioned beam from a first beam condition to provide a desired angular intensity distribution of the radiation beam at a patterning device, patterning the first conditioned beam with a first pattern in its cross-section to form a first patterned beam, the first pattern being provided by the patterning device, and projecting the first patterned beam onto a sensor capable of providing a sensor output signal; and in an exposure phase: steering the different parts of the radiation beam individually into different directions to form a second conditioned beam from a second beam condition to provide a desired angular intensity distribution of the radiation beam at the patterning device, the second beam condition being different from the first beam condition, patterning the second conditioned beam with a second pattern to form a second patterned beam, different from the first pattern, in its cross-section, the second pattern being provided by the patterning device, and projecting the second patterned beam onto a target portion of the substrate.