Trench capacitors with buried isolation layer formed by an oxidation process and methods for manufacturing the same

摘要

A method for forming a trench capacitor includes: removing a portion of the substrate to form a trench within the substrate; forming at a buried isolation layer within the substrate; forming in the substrate a first electrode of the trench capacitor at least in areas surrounding a lower portion of the trench; forming a dielectric layer of the trench capacitor; and forming a second electrode of the trench capacitor in the trench. The buried isolation layer intersects with the trench and has one or more gaps for providing body contact between a first substrate area above the buried isolation layer and a second substrate area below the buried isolation layer.