Patent ID: 6645849
Filing Date: 2003-11-11
Classification: H01L

Abstract:
A method for manufacturing a semiconductor device, comprising:forming a first interlevel dielectric (ILD) film with an opening over a semiconductor substrate; forming a diffusion barrier layer along the first ILD film having the opening; forming a lower plug in the opening of the first ILD film coated with the diffusion barrier layer, the lower plug having a second single diameter and having substantially vertical sidewalls and a substantially flat top surface that is substantially level with a top surface of the first ILD film; forming a second ILD film over the first ILD film, the second ILD film having a groove through which at least the recession of the lower plug is exposed; depositing over the second ILD film having the groove a metal to form an adhesive layer on the groove of the second ILD film and the recession of the lower plug; and forming a conductive layer over the adhesive layer to fill the groove of the second ILD film and the recession of the lower plug, such that the conductive layer includes an upper portion and a protrusion extending vertically underneath the upper portion into the interior of the lower plug, the protrusion having substantially vertical sidewalls substantially parallel to the sidewalls of the lower plug.