Patent ID: 7199414

Claim:
A storage capacitor, comprising: a substrate having a trench formed therein, said trench having sidewalls, a bottom, an upper portion and a lower portion; a collar disposed at said sidewalls in said upper portion of said trench; a lower capacitor electrode; a storage dielectric disposed at said sidewalls of said lower portion of said trench, at said bottom of said trench and at said collar in said upper portion of said trench; an upper capacitor electrode being a conductive layer disposed at said storage dielectric in said lower portion of said trench, said conductive layer being formed of a material selected from the group consisting of metal silicide, metal nitride, metal carbide, WN, WSiN, WC, TiN, TaN, and TaSiN; a doped layer selected from the group consisting of a SiGe layer, a SiC layer, and a GaAs layer or a doped filling selected from the group consisting of a SiGe filling, a SiC filling, and a GaAs filling disposed on a side of said conductive layer remote from said storage dielectric and said doped layer or said doped filling covering said upper capacitor electrode and being disposed at said storage dielectric at said upper portion of said trench; said storage dielectric being disposed between said collar and said doped layer or said doped filling in said upper portion of said trench; and said doped layer or said doped filling being suitably doped to reduce an interfacial stress between said storage dielectric and said conductive layer.