US Patent 7851326 Method for producing deep trench structures

A method for producing deep trench structures in an STI structure of a semiconductor substrate is provided, with the following successive process steps: subsequent to a full-area filling of STI recesses introduced into a semiconductor substrate with a first filler material, a first surface of a semiconductor structure is subjected to a CMP process to level the applied filler material and produce the STI structure; the leveled STI structure thus produced is structured; using the structured, leveled STI structure as a hard mask, at least one deep trench is etched in the area of this STI structure to create the deep trench structures.