Patent ID: 6200873
Filing Date: 2001-03-13
Classification: H01L

Abstract:
A method for fabricating a trench capacitor, which comprises the following steps:providing a substrate;forming a trench with a trench wall in the substrate;providing a first layer on the trench wall;providing a second layer on the first layer on the trench wall;filling the trench with a first filling material;removing the first filling material from an upper region of the trench to define a collar region;subsequently removing the second layer from the upper region of the trench;subsequently removing the first filling material from the lower region of the trench;subsequently removing the first layer from the upper region of the trench;subsequently locally oxidizing the upper region of the trench to produce an insulation collar;removing the first and second layers from a lower region of the trench;forming a dielectric layer in the lower region of the trench and on an inner side of the insulation collar; andfilling the trench with a conductive second filling material.