A semiconductor device includes a protective layer, a redistribution pattern, a pad pattern and an insulating polymer layer. The protective layer may be formed on a substrate. The redistribution pattern may be formed on the protective layer. An upper surface of the redistribution may be substantially flat. The pad pattern may be formed directly on the redistribution pattern. An upper surface of the pad pattern may be substantially flat. The insulating polymer layer may be formed on the redistribution pattern and the pad pattern. An upper surface of the insulating polymer layer may be lower than the upper surface of the pad pattern. The semiconductor device may have a high reliability.