Patent ID: 6380073
Filing Date: 2002-04-30
Classification: H01L

Abstract:
A method for forming a metal interconnection structure without corner faceted, comprising:providing a semiconductor substrate having a first stop layer formed thereon, a first inter-metal layer being formed on the surface of the first stop layer; etching said first inter-metal layer to form an opening in said inter-metal layer using a first photoresist as an etching mask; forming a second stop layer on the surface of said first inter-metal layer; forming a dielectric layer to fill up said opening and on the surface of said second stop layer; etching back said dielectric layer until said second stop layer is exposed; forming a second inter-metal layer on the surface of said second stop layer and said dielectric layer; etching said second inter-metal layer using a second photoresist as an etching mask; forming a third stop layer on the surface of said second inter-metal layer, said second stop layer and said dielectric layer; etching back said third layer until said dielectric layer being exposed; removing said dielectric layer in said opening; etching said third stop layer, said second stop layer and said first stop layer until said second inter-metal layer, said first inter-metal layer and said semiconductor substrate being exposed; depositing a barrier layer into a via trench which is formed into said first inter-metal layer and said second inter-metal layer; filling the trenches with a metal layer; and planarizing said metal layer to expose surface of said second dielectric layer in order to form a metal via structure.