Trench capacitor with capacitor electrodes
AssigneeInfineon Technologies AG
InventorMartin Schrems
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Abstract
A trench capacitor for use in a semiconductor memory cell is formed in a substrate. The trench capacitor includes a trench having an upper region and a lower region, an insulation collar formed in the upper region on a trench wall of the trench, and a buried well, through which the lower region of the trench at least partly extends. The trench capacitor further includes, as an outer capacitor electrode, a conductive layer lining the lower region of the trench and the insulation collar, a dielectric layer lining the conductive layer, and a conductive trench filling which is filled into the trench as an inner capacitor electrode. A method of fabricating a trench capacitor is also provided.
Claims9
A trench capacitor, comprising:
- a substrate formed with a trench having a trench wall, said trench having an upper region and a lower region;
- an insulation collar formed in said upper region of said trench wall;
- a buried layer, said lower region of said trench at least partially extending through said buried layer;
- a dielectric layer disposed at said trench wall in said lower region of said trench and at said insulation collar;
- a conductive trench filling provided in said trench and serving as an inner capacitor electrode;
- a conductive layer serving as an outer capacitor electrode, said conductive layer being disposed such that, in said lower region of said trench, said conductive layer is disposed between said substrate and said dielectric layer and, at said insulation collar, said conductive layer is disposed between said insulation collar and said dielectric layer;
- and
- said conductive layer including a material selected from the group consisting of a metal, a metal silicide, and a metal nitride.
Dependencies are inferred from the claim text.