Patent ID: 7459710

Claim:
A method of calibrating a lithographic apparatus, comprising: (a) patterning a beam using an array of individually controllable elements; (b) directing the patterned beam towards a substrate using a projection system; (c) locating a detector having detector elements in a path of the patterned beam, each of the detector elements being larger than a spot corresponding to a single element of the array of individually controllable elements; (d) selectively activating the detector elements; (e) measuring an amount of radiation received on respective ones of the detector elements from the patterned beam; and (f) calibrating elements of the array of individually controllable elements based on the measuring step (e), wherein, step (d) comprises activating elements in the array of individually controllable elements during a measurement interval in step (e) so that only one of the elements of the array of individually controllable elements corresponding to a respective one of the detector elements is activated, steps (d) and (e) are repeated with a different one of the elements in the array of individually controllable elements corresponding to a respective one of the detector elements being activated, and the detector is moved relative to the patterned beam between repeats of steps (d) and (e).