Method for manufacturing capacitor of semiconductor device

PURPOSE: A method for manufacturing a capacitor of a semiconductor device is provided to prevent a bit line material, i.e., tungsten from being transformed by an interval of process time, by shortening the time necessary for the thermal process within five minutes by using N2O gas. CONSTITUTION: A nitride layer is formed on a storage electrode of a capacitor by a rapid thermal nitridation process. A Ta2O5 layer is deposited on the nitride layer, and is thermally processed by the rapid thermal process using N2O gas to form an SiON layer on an interface between the storage electrode of the capacitor and the Ta2O5 layer. A plate electrode of the capacitor is formed on the Ta2O5 layer.