Patent ID: 6352921
Filing Date: 2002-03-05
Classification: H01L

Abstract:
A method of forming boron carbide as an etch-stop and barrier layer for copper dual damascene metallization comprising the steps of:providing a semiconductor substrate having a first conductive layer; forming a boron carbide (BC) passivation layer over said conductive layer; forming a first dielectric layer over said BC passivation layer; forming a BC etch-stop layer over said first dielectric layer; forming a second dielectric layer over said BC etch-stop is layer; forming a BC cap layer over said second dielectric layer; forming a first photoresist layer over said cap layer and patterning said photoresist layer with a mask comprising a via hole pattern; etching through said via pattern in said first photoresist layer to form said via hole in said BC cap layer and said second dielectric layer until said BC etch-stop layer is reached; etching through said via hole pattern to form said via hole in said BC etch-stop layer; etching further said via hole pattern into said first dielectric layer until BC passivation layer is reached; removing said first photoresist layer; forming a second photoresist layer over said BC cap layer including said via hole in said second dielectric layer; patterning said second photoresist layer with a mask comprising a line trench pattern; etching through said line trench pattern in said second photoresist layer into said BC cap layer and said second dielectric layer and into said BC etch-stop layer; etching further through said hole pattern in said BC etch-stop layer and extending said hole pattern into said BC passivation layer thus forming a dual damascene structure comprising a composite hole and line trench pattern in said substrate; removing said second photoresist layer; forming a barrier lining on the inside walls of said dual damascene structure; forming metal over said barrier lining in said dual damascene structure; and forming a combination barrier and passivation layer over said substrate including over said dual damascene structure.