A method is provided for fabricating stripe structures. The method includes providing a substrate; and forming a to-be-etched layer on the substrate. The method also includes forming a hard mask pattern having a first stripe on the to-be-etched layer; and forming a photoresist pattern having a stripe opening on the to-be-etched layer and the hard mask pattern having the first stripe. Further, the method includes forming a polymer layer on a top surface and side surfaces of the photoresist pattern to reduce a width of the stripe opening; forming hard mask patterns having a second stripe by etching the hard mask pattern having the first stripe using the photoresist pattern having the polymer layer as an etching mask; and forming the stripe structures by etching the to-be-etching layer using the hard mask pattern having the second stripe as an etching mask until the substrate is exposed.