Treatment for adhesion improvement

A method comprising:

• forming an opening in an insulating layer, the opening exposing a contact underlying the insulating layer, the opening having sidewalls and a bottom;
• treating the sidewalls and the bottom of the opening with a nitrogen-based plasma process, the nitrogen-based plasma process incorporating free nitrogen atoms into the sidewalls of the opening;
• and
• depositing a metal into the opening to form a metallic interlayer in the opening, the metallic interlayer comprising a combination of the metal and the free nitrogen atoms;
• and
• continuing to deposit the metal into the opening to form a metal plug in the opening over the metallic interlayer.

A method comprising:

• etching an opening in an insulating layer to expose a contact feature underlying the insulating layer;
• depositing nitrogen into sidewalls of the opening;
• and
• depositing a metal material in the opening, the metal material combining with the nitrogen to form a first layer, the first layer comprising a compound of the metal material and nitrogen.