Patent ID: 6326296
Filing Date: 2001-12-04
Classification: H01L

Abstract:
A method of forming a dual damascene structure with improved contact hole edge profile comprising the steps of:providing a semiconductor substrate having a substructure comprising devices formed in said substrate;forming a first interlevel dielectric (ILD) layer over said substrate;forming an etch-stop layer over said first ILD layer;forming a first photoresist layer over said etch-stop layer;patterning said first photoresist layer with a contact hole pattern;etching said contact hole pattern into said etch-stop layer;etching further said contact hole pattern into said first ILD layer until said substructure of said substrate is reached;removing said first photoresist layer from said substrate;forming organic material over said etch-stop layer and filling said contact hole opening in said etch-stop layer and in said first ILD layer with said organic material;performing etch-back of said organic material to expose the surface of said etch-stop layer, such that the surface of said organic material remaining in said contact hole is left flat and level with respect to the surface of said etch-stop layer;forming a second interlevel dielectric (ILD) layer over said etch-stop layer including said contact hole opening in said etch-stop layer and in said first ILD layer filled with said organic material;forming a second photoresist layer over said second ILD layer;patterning said second photoresist layer with a conductive line opening pattern;etching through said conductive line opening in said second photoresist layer into said second ILD layer until etch-stop layer is reached;removing said second photoresist layer;removing remaining said organic material from said contact hole opening in said first ILD layer;forming metal in said conductive line opening in said second ILD layer and contact hole opening through said etch-stop layer and in said first ILD layer; andremoving said metal from the surface of said substrate for subsequent process steps to complete the fabrication of a semiconductor substrate.