Patent ID: 6689695
Filing Date: 2004-02-10
Classification: H01L

Abstract:
A method of forming a multi-purpose composite mask for dual damascene patterning comprising the steps of:providing a substrate having a stack of dielectric layers comprising a barrier layer, a first dielectric layer, an etch-stop layer, a second dielectric layer and a cap layer formed thereon in said order wherein said first dielectric layer comprises a low-k material including black diamond; forming a via opening in said stack of dielectric layers; forming a polymeric dielectric layer over said substrate, including over said via opening; forming a silicon based dielectric layer over said polymeric dielectric layer; patterning said silicon based and polymeric dielectric layers to define a trench opening, and partially removing said polymeric dielectric layer from said via opening; using said polymeric dielectric as a via protector, etching further said trench opening until said etch-stop layer is reached; and cleaning any remaining polymeric dielectric in said via to complete the forming of said dual damascene structure.