The present disclosure provides an exposure method for a semiconductor device, in which whether a specific pattern corresponds to a sparse area or a dense area is decided to employ a specific phase-shift mask and by which critical dimension uniformity and resolution of the pattern are enhanced. One example method includes defining a hole area for a plurality of holes into a dense area and a sparse area, coating a photoresist layer on a substrate having a plurality of elements formed thereon, carrying out a first exposure on the photoresist layer using a first photomask having patterns corresponding to the dense and sparse areas, respectively, and carrying out a second exposure on the photoresist layer using a second photomask having at least two halftone layers provided to portions corresponding to the dense and sparse areas, respectively wherein the at least two halftone layers differ from each other in transmitivity, respectively.