Patent ID: 6556277
Filing Date: 2003-04-29
Classification: G03F

Abstract:
An apparatus for reducing proximity effects, the apparatus comprising:an exposure tool providing at least a first illumination condition and a second illumination condition; and a photomask adapted for placement between the exposure tool and a substrate, the exposure tool illuminating the substrate through the photomask using the first illumination condition and the exposure tool illuminating the substrate through the photomask using the second illumination condition, the photomask comprising a plurality of densely packed features having a first width and a plurality of relatively isolated features having a second width substantially the same as the first width, wherein the first illumination condition causes the densely packed features and the relatively isolated features to transfer to the substrate, such that the densely packed features have a first transferred width and the isolated features have a second transferred width, and wherein the second illumination condition causes the densely packed features and the relatively isolated features to transfer to the substrate, such that, when developed, a developed first width of the densely packed features is substantially the same as a developed second width of the relatively isolated features.