A method for fabricating a capacitor includes: forming a storage node contact plug over a substrate; forming an insulation layer having an opening exposing a surface of the storage node contact plug over the storage contact plug; forming a conductive layer for a storage node over the insulation layer and the exposed surface of the storage node contact plug through two steps performed at different temperatures; performing an isolation process to isolate parts of the conductive layer; and sequentially forming a dielectric layer and a plate electrode over the isolated conductive layer.