Patent ID: 6700153
Filing Date: 2004-03-02
Classification: H01L,Y10T

Abstract:
A capacitor comprising:an interlayer insulating layer having a surface; a conductive plug extending at a depth from the surface of the interlayer insulating layer; an etch stop layer extending over the insulating layer and exposing the conductive plug; a cylindrical lower electrode defined by a cylindrical wall and a bottom wall which extends over a surface of the conductive plug and over a portion of the etch stop layer adjacent the conductive plug, wherein the cylindrical wall extends upwardly from the bottom wall away from the surface of the interlayer insulating layer; a dielectric layer formed over the cylindrical lower electrode; and an upper electrode formed over the dielectric layer; wherein the cylindrical wall of the cylindrical lower electrode is defined by an upper cylindrical wall portion, a lower cylindrical wall portion, and an intermediate cylindrical wall portion located between the upper and lower cylindrical wall portions; wherein a diameter of the upper cylindrical wall portion and a diameter of the lower cylindrical wall portion increase with an increase in a distance from the surface of the bottom wall, wherein a diameter of the intermediate cylindrical wall portions decreases with an increase in a distance away from the surface of the bottom wall, and wherein A&gE;C, C>B, and C>D where A is a diameter of the upper cylindrical wall portion at a location farthest from the bottom wall, B is a diameter of the upper cylindrical wall portion at a location nearest to the bottom wall, C is a diameter of the lower cylindrical wall portion at a location farthest from the bottom wall, and D is a diameter of the lower cylindrical wall portion at the bottom wall.