Photomasks, methods of exposing a substrate to light, methods of forming a pattern, and methods of manufacturing a semiconductor device

The method of forming a pattern includes forming a first photosensitive layer pattern including a first pattern in a first region of a substrate and a second pattern in a second region of the substrate, by performing a first photolithography process using a photomask having a first mask region and a second mask region. The first pattern is transferred from the first mask region, and the second pattern is transferred from the second mask region. The method further includes forming a second photosensitive layer pattern including a third pattern in the second region of the substrate and a fourth pattern in the first region of the substrate, by performing a second photolithography process using the photomask. The third pattern is transferred from the first mask region, and the fourth pattern is transferred from the second mask region.