The present disclosure provides a method for semiconductor manufacturing in accordance with some embodiments. The method includes providing a substrate and a patterning layer over the substrate, wherein the substrate includes a plurality of features to receive a treatment process; forming at least one opening in the patterning layer, wherein the plurality of features is partially exposed in the at least one opening; applying a directional etching to expand the at least one opening in a first direction, thereby forming at least one expanded opening; and performing the treatment process to the plurality of features through the at least one expanded opening.