Patent ID: 7233386

Claim:
A method of optimizing an imaging performance of a projection exposure system, the projection exposure system comprising an illumination optical system including a light source for illuminating a patterning structure and a projection optical system for imaging a region of the illuminated patterning structure onto a corresponding field in a substrate-plane, the method comprising: setting the field to a first exposure field, the first exposure field having first field dimensions and a first position within a maximum field exposable by the projection exposure system; determining a first setting of optical parameters of the projection exposure system in dependence of the first field dimensions; setting optical parameters of the projection exposure system to the first setting such that an imaging performance quantity within the first exposure field at the first setting satisfies a first performance condition; changing the field to a second exposure field, the second exposure field having at least one of second field dimensions different from the first field dimensions and a second position within the maximum field exposable by the projection exposure system, which second position is different from the first position; and changing the optical parameters of the projection exposure system to a second setting such that an imaging performance quantity within the second exposure field at the second setting satisfies a second performance condition.