Patent ID: 7776685

Claim:
A method of forming a capacitor comprising: forming an insulating layer on a semiconductor substrate; forming an opening in the insulating layer; forming a conductive layer on an upper surface of the insulating layer and a lower surface and sidewalls of the opening; forming a buffer layer on the conductive layer, the buffer layer filling the opening and including a major portion of a copolymer having from 61 to 75 weight percent benzyl methacrylate; from 8 to 15 weight percent alkyl acrylic acid; and with a remainder being hydroxy alkyl methacrylate; removing an upper portion of the buffer layer using a developer solution to expose an upper portion of the conductive layer, a lower portion of the buffer layer substantially filling the opening; removing the upper portion of the conductive layer to separate lower electrode structures; removing the lower portion of the buffer layer; forming a dielectric layer on the lower electrode structures; and forming an upper electrode on the dielectric layer.