| 摘要 |
The present invention provides a method for fabricating a trench capacitor with an insulation collar ( 10 ) in a substrate ( 1 ), which is electrically connected to the substrate ( 1 ) on one side via a buried contact, having the steps of: providing a trench ( 5 ) in the substrate ( 1 ) using a hard mask ( 2, 3 ) with a corresponding mask opening; providing a capacitor dielectric ( 30 ) in the lower and central trench region, the insulation collar ( 10 ) in the central and upper trench region and an electrically conductive filling ( 20 ) as far as the top side of the insulation collar ( 10 ); providing a spacer ( 21 ') made of a conductive material above the insulation collar ( 10 ) in electrical contact with the substrate ( 1 ); completely filling the trench ( 5 ) with a filling material ( 23; 50 ) above the liner layer ( 22; 40 ); carrying out an STI trench fabrication process; removing the filling material ( 23; 50 ) and sinking the electrically conductive filling ( 20 ) to below the top side of the insulation collar ( 10 ); providing a metallic filling ( 25 ) in the trench ( 5 ) and etching back the metallic filling ( 25 ) as far as the top side of the spacer ( 21 '); and providing an insulation region (IS) on one side and a contact region (KS) on a different side with respect to the substrate ( 1 ) above the insulation collar ( 10 ) by partly removing the spacer ( 21 ').
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