Patent ID: 6878615
Filing Date: 2005-04-12
Classification: H01L

Abstract:
1. A method to solve via poisoning for insulative porous low-k materials comprising the steps of: providing a substrate having a first and second insulative layers separated from each other by an intervening etch-stop layer, and having a passivation layer disposed on a side of said first insulative layer opposite from said etch-stop layer; forming a hole opening in said first and second insulative layers, including said intervening etch-stop layer; forming a low-k protection layer over said second insulating layer, including in said hole opening, wherein said low-k protection layer prevents outgassing from said first and second insulative layers; forming a trench opening over said hole opening to form a dual damascene structure; selectively removing part of said low-k protection layer so as to leave a portion thereof on verticle walls of said hole opening; removing a portion of said passivation layer at an end of said hole opening remote from said second insulative layer; forming a barrier layer on the vertical walls of said trench opening and on the portion of said low-k protection layer on the vertical walls of said hole opening; forming a metal layer on said barrier layer in said dual damascene structure; and performing chemical mechanical polishing (CMP), to complete the forming of said dual damascene structure.