METHOD OF FORMING A CAPACITOR

摘要

A method for forming a capacitor is provided to form easily a dielectric layer and an upper electrode on a lower electrode by widening a lower width of the lower electrode in an upper width of the lower electrode. A lower mold layer is formed on a substrate(100). An upper mold layer is formed on the lower mold layer. An etch ratio of a material for forming the upper mold layer is lower than an etch ratio of a material for forming the lower mold layer. A first mold layer pattern including a first opening having a narrow width by etching partially the lower mold layer and the upper mold layer in an anisotropic etch manner. A second mold layer pattern including a second opening having a wide width by etching the lower mold layer exposed to a sidewall of the first opening by using an etch solution. A lower electrode(142) is formed along a surface of the second mold layer pattern exposed to an inner wall of the second opening. A third mold layer pattern is formed to surround a lower part of the lower electrode by removing a part of the upper mold layer. A dielectric layer(144) and an upper electrode are formed along the third mold layer pattern and the surface of the lower electrode.