A photoresist composition and methods of using the same are disclosed. The photoresist includes a polymer backbone, an acid labile group (ALG) chemically bonded to the polymer backbone, a photo-acid generator (PAG), a solvent, and a silicon-containing unit that is chemically bonded to one of: the ALG and a crosslinker. A method of using the photoresist composition includes forming a layer of the photoresist over a substrate, performing an exposing process to the photoresist layer; and developing the photoresist layer, thereby forming a patterned photoresist layer. The patterned photoresist layer includes the silicon-containing unit.