A semiconductor device may include a cell capacitor including first lower electrodes, a first upper support layer pattern, a first dielectric layer, and a first upper electrode. The decoupling capacitor may include second lower electrodes, a second upper support layer pattern, a second dielectric layer, and a second upper electrode. The first and second lower electrodes may be arranged in a honeycomb pattern at each vertex of a hexagon and a center of the hexagon. The first upper support layer pattern may be connected to upper sidewalls of the first lower electrodes. The first upper support layer pattern may correspond to a first plate defining first openings. The second upper support layer pattern may be connected to upper sidewalls of the second electrodes. The second upper support layer pattern may correspond to a second plate defining second openings having a shape different from a shape of the first opening.