A semiconductor device includes a semiconductor substrate including a pad region and a peripheral region, a first buffer layer formed to include a capacitor over the semiconductor substrate in the pad region, a second buffer layer formed to include a first contact pad over the first buffer layer, and a third buffer layer formed to include a second contact pad over the first contact pad. The semiconductor device, by additionally forming a buffer layer at a lower part in the pad region, reduces a stress caused by wire bonding. Thus, an applied stress to a lower structure in the pad region is also reduced. As a result, the buffer layer prevents formation of an electrical bridge between the pad region and the peripheral region.