Patent ID: 7189614
Filing Date: 2007-03-13
Classification: H01L

Abstract:
1. A method for fabricating a trench capacitor with an insulation collar in a substrate, which is electrically connected to the substrate on one side via a buried contact, comprising: providing a trench in the substrate using a hard mask with a corresponding mask opening; providing an at least partial trench filling; providing a liner comprising Al subjecting the liner to a heat treatment for increasing the crystallinity of the liner; carrying out an oblique implantation of impurity ions onto the liner for the purpose of altering the etching properties of an implanted partial region of the liner; selectively removing the implanted partial region of the liner by means of a first etching for the purpose of forming a liner mask from a complimentary partial region of the liner, which partially masks a top side of the trench filling; removing a part of the trench filling by means of a second etching using the liner mask; and replacing the removed part of the trench filling.