A method for manufacturing a capacitor of a semiconductor device includes: forming an interlayer insulating film including a contact plug over a semiconductor substrate; forming a first stack film including a capacitor oxide film and a nitride film over the interlayer insulating film; etching the first stack film to form a first stack pattern and a contact hole that exposes the contact plug; forming a lower electrode in the contact hole; forming a capping oxide film continuously over the first stack pattern to form a bridge connecting the neighboring first stack patterns; forming an etching barrier film including cavities over the capping oxide film; performing a blanket etching process onto the etching barrier film including cavities until the capacitor oxide film is exposed to form a nitride film pattern; and removing the exposed capacitor oxide film.