Method of manufacturing a capacitor with a bi-layer ta2o5 capacitor dielectric in a semiconductor device including performing a plasma treatment on the first ta2o5 layer

Abstract

There is disclosed a method of manufacturing a capacitor in a semiconductor device capable of effectively removing the organic impurity of a Ta O film by performing an in-situ plasma process using the mixture gas of nitrogen and oxygen during the process of forming the Ta O film as the dielectric film of the capacitor. Thus, it can reduce the impurity of the Ta O film to increase the supply of oxygen, and thus can improve the dielectric and leak current characteristic of the Ta O film. Further, it can prohibit oxidization of the underlying electrode, thus reducing the thickness of the equivalent oxide film of the capacitor as possible and sufficiently securing the capacitance of the capacitor. The method according to the present invention includes forming a polysilicon film on a semiconductor substrate in which a given underlying structure is formed; sequentially forming a first buffer layer and a metal layer on the polysilicon film to form a lower electrode; forming a Ta O film on the metal layer, wherein the process of depositing the Ta O film is performed by a plasma process under the mixture gas atmosphere of nitrogen and oxygen; and forming a second buffer layer and an upper electrode on the Ta O film.