Patent ID: 7286207

Claim:
A method for exposing a semiconductor wafer with a pattern from a mask in an exposure tool, the exposure tool including a lens system and a light source configured to emit an exposure light beam that is adjustable to at least two different spectral wavelengths, the method comprising: providing the semiconductor wafer and the mask to the exposure tool; setting the light source of the exposure tool to emit a first light beam at a first wavelength; performing a first exposure of the semiconductor wafer with the pattern from the mask through the lens system and via the first light beam; setting the light source of the exposure tool to emit a second light beam at a second wavelength; adjusting the lens system of the exposure tool to compensate for an amount of image shift of a pattern within a portion of an image field with respect to the first exposure due to chromatic aberration; and performing a second exposure of the semiconductor wafer with the pattern from the mask through the adjusted lens system and via the second light beam.