In-Situ Formation of Silicon and Tantalum Containing Barrier

摘要

A method includes forming an opening in a dielectric layer, and forming a silicon rich layer on a surface of the dielectric layer. A portion of the silicon rich layer extends into the opening and contacts the dielectric layer. A tantalum-containing layer is formed over and the contacting the silicon rich layer. An annealing is performed to react the tantalum-containing layer with the silicon rich layer, so that a tantalum-and-silicon containing layer is formed.