A semiconductor device includes an internal circuit and a cell-type power decoupling capacitor. The cell-type power decoupling capacitor is formed on a semiconductor substrate using a stack cell capacitor process. The cell-type power decoupling capacitor stabilizes a supply voltage to provide the stabilized supply voltage to the internal circuit. Accordingly, the semiconductor device including the cell-type power decoupling capacitor may be insensitive to power noise and may occupy a small area on a chip.