Deposition methods for barrier and tungsten materials

A method for depositing materials on a substrate, comprising:

• depositing a cobalt-containing material on a dielectric surface of a substrate;
• exposing the cobalt-containing material to a soak gas comprising a reducing gas during a soak process;
• forming a tungsten material over the cobalt-containing material;
• and
• heating the substrate to form a cobalt silicide layer from a lower portion of the cobalt-containing material and a metallic cobalt layer from an upper portion of the cobalt-containing material.

A method for depositing materials on a substrate, comprising:

• forming a cobalt-containing material on a dielectric surface of a substrate, wherein the cobalt-containing material comprises a metallic cobalt layer and a cobalt silicide layer;
• exposing the cobalt-containing material to a soak gas comprising a silane during a soak process;
• depositing a tungsten nucleation layer over the cobalt-containing material;
• and
• depositing a tungsten bulk layer over the tungsten nucleation layer.