The present disclosure provides a method for manufacturing a semiconductor device. The method includes coating a photoresist on a substrate. The photoresist is exposed to radiation. The radiation exposed photoresist is baked. The radiation exposed and baked photoresist is developed to create an image pattern. The image pattern is treated with a treating material. An ion implantation process is performed to the substrate and the treated image pattern. The image pattern is stripped from the substrate. A carbon atom ratio of the treating material is less than a carbon atom ratio of the photoresist.