Patent ID: 6881620
Filing Date: 2005-04-19
Classification: H01L

Abstract:
1. A method of fabricating a trench capacitor, comprising: providing a substrate, wherein the substrate has a patterned liner layer and a patterned mask layer formed thereon and a trench formed therein, an electrode formed in the substrate at a bottom of the trench and a capacitor dielectric layer formed on the surface of the trench; forming a first conductive layer at the bottom of the trench; forming a protective layer over the mask layer and on the surface of the trench; forming a collar oxide layer on the surface of the protective layer; removing the protective layer and the collar oxide layer on the surface of the first conductive layer; depositing a material into the trench to form a material layer; removing a portion of the material layer inside the trench to form a first opening, wherein a top surface of the material layer is at a level higher than the liner layer; removing the collar oxide layer and the protective layer not covered by the material layer; removing a portion of the mask layer and the protective layer on the sidewall of the first opening to form a second opening, wherein the second opening has a width greater than the first opening; removing the material layer; depositing conductive material into the trench to form a second conductive layer; removing a portion of the second conductive layer at a top of the trench so that the second conductive layer partially fills the trench; removing the collar oxide layer and the protective layer on the sidewall of the trench and not covered by the second conductive layer; and depositing conductive material into the trench to form a third conductive layer, wherein the third conductive layer completely fills the trench.