Production of trench capacitor, used for semiconductor memory cell, comprises providing trench in substrate using hard mask with corresponding mask openings, providing capacitor dielectric in trench, and further processing

摘要

Production of a trench capacitor comprises providing a trench (5) in the substrate (1) using a hard mask (2, 3) with corresponding mask openings, providing a capacitor dielectric (30) in the trench and insulating collar (10) in the trench, providing an electrically conducting filler (20) in the trench to protrude over the upper side of the hard mask in the form of a plug, isotropically back-etching the part of the filler protruding over the upper side of the hard mask to a pre-determined thickness, forming a mask over the protruding part of the filler, removing the filler using the mask up to below the upper side of the insulating collar exposing the dielectric in a connecting region (KS), removing the exposed connecting region and the mask, and filling the trench with a further electrically conducting filler (20') to form a trenched contact.