Methods for forming a semiconductor device including fine patterns are provided. The method may include forming a mask layer including first holes spaced apart from each other in a first direction and a second direction. The method may also include forming local mask patterns on the mask layer and forming a sacrificial layer on the mask layer filling the first holes and surrounding the local mask patterns. The local mask patterns may be offset from the first holes in the first direction and the second direction. The method may further include removing the local mask patterns to form openings in the sacrificial layer exposing the mask layer and etching the mask layer through the opening to form second holes in the mask layer.