A multiple exposure method for enhancing the image resolution in a
lithographic system is disclosed. The method comprises, for example,
decomposing a desired pattern to be printed on the substrate into at
least two constituent sub-patterns that are capable of being optically
resolved by the lithographic system, coating the substrate with a
positive tone resist layer and a relatively thin positive tone
developable material layer on top of a target layer which is to be
patterned with the desired dense feature pattern. The positive tone
developable material absorbs exposure radiation during a first patterning
exposure and, after development, during a second patterning exposure to
prevent exposure of at least a portion of the positive tone resist layer,
underneath exposed portions of the positive tone developable material
layer, to an exposure dose above a fraction of an energy-to-clear
exposure dose associated with the positive tone resist layer.