Patent ID: 8927421
Filing Date: 2015-01-06
Classification: H01L

Abstract:
1. A method comprising: forming a via and trench structure having a via portion with a smaller cross sectional area than a trench portion, the via portion exposing a wiring structure formed on a surface of an underlying substrate; forming a first layer on a surface of the via and trench structure which is in direct contact with a wiring structure on a surface of the underlying substrate; forming a first metal layer on the first layer; forming a second metal layer on the first metal layer; migrating the second metal layer to a bottom of the via portion of the via and trench structure; filling the via and trench structure with additional material; planarizing the additional material and forming a capping layer on the planarized additional material; and after forming the capping layer, redistributing impurities in the first metal layer to a surface of the planarized additional material.