The method includes forming a first dielectric layer on a substrate, forming a via in the first dielectric layer, sequentially forming a first metal pattern, a first metal oxide pattern, a second metal pattern, and an antireflective pattern on the first dielectric layer, and performing an annealing process to react the first metal oxide pattern and the second metal pattern with each other to form a second metal oxide pattern. The forming the second metal oxide pattern includes forming the second metal oxide pattern by a reaction between a metal element of the second metal pattern and an oxygen element of the first metal oxide pattern.