Methods of forming patterns are provided. The methods may include sequentially forming an etch-target layer and a photoresist layer on a substrate, exposing two first portions of the photoresist layer to light to transform the two first portions into two first photoresist patterns and exposing a second portion of the photoresist layer to light to transform the second portion into a second photoresist pattern disposed between the two first photoresist patterns. The method may also removing portions of the photoresist layer to leave the two first photoresist patterns and the second photo resist pattern on the etch-target layer such that the etch-target layer is exposed.