In a method for fabricating a semiconductor device, a semiconductor device is provided including an interlayer dielectric film and first and second hard mask patterns sequentially stacked thereon. A first trench is provided in the interlayer dielectric film through the second hard mask pattern and the first hard mask pattern. A filler material is provided on the interlayer dielectric film and the first and second hard mask patterns to fill the first trench. First and second hard mask trimming patterns are formed by trimming sidewalls of the first and second hard mask patterns and removing the filler material to expose the first trench. A damascene wire is formed by filling the first trench with a conductive material.