Contact structure and formation thereof

A semiconductor device, comprising:

• a silicide;
• a metal layer;
• a first dielectric layer overlying the silicide;
• a glue layer overlying the silicide and between a first portion of the first dielectric layer and a second portion of the first dielectric layer, wherein the first dielectric layer is between the metal layer and the glue layer;
• and
• a cobalt plug over the silicide, wherein:
• the glue layer is between the silicide and the cobalt plug, and
• the cobalt plug has a different composition than the metal layer.

A semiconductor device, comprising:

• a silicide;
• a metal layer overlying the silicide;
• a dielectric layer;
• a glue layer overlying the silicide, wherein:
• the glue layer is in contact with a sidewall of the dielectric layer, and
• the glue layer is spaced apart from the metal layer;
• and
• a cobalt plug overlying the silicide, wherein:
• the glue layer is between the silicide and the cobalt plug, and
• the glue layer is between the metal layer and the cobalt plug.