A semiconductor device is provided. A cell region is disposed in a substrate. The cell region includes a memory cell. A peripheral region is disposed in the substrate. The peripheral region is adjacent to the cell region. The peripheral region has a trench isolation, a first active region and a second active region. The trench isolation is interposed between the first active region and the second active region. A common gate pattern is disposed on the peripheral region. The common gate pattern extends in a first direction and partially overlaps the first active region, the second active region and the trench isolation. A buried conductive pattern is enclosed by the trench isolation. The buried conductive pattern extends in a second direction crossing the first direction. A top surface of the buried conductive pattern is lower than a bottom surface of the common gate pattern.