Semiconductor devices having metal interconnections, semiconductor cluster tools used in fabrication thereof and methods of fabricating the same

A semiconductor device comprising:

• a semiconductor substrate including a conductive pattern;
• an insulating layer on the conductive pattern and the semiconductor substrate, the insulating layer having an opening which penetrates the insulating layer to expose a portion of the conductive pattern;
• a metal interconnection filling the opening;
• and
• a first diffusion barrier pattern disposed between the metal interconnection and the conductive pattern,
• wherein the first diffusion barrier pattern contains oxygen atoms.

A semiconductor cluster tool, comprising:

• a first chamber configured to form a preliminary diffusion barrier layer on a substrate having an opening, to supply oxygen atoms onto the preliminary diffusion barrier layer to form a first diffusion barrier layer, and/or to form a second diffusion barrier layer on the first diffusion barrier layer;
• a second chamber configured to form a deposition resistant layer on an upper sidewall of the second diffusion barrier layer in the opening and a top surface of the second diffusion barrier layer outside the opening, thereby exposing a lower sidewall of the second diffusion barrier layer in the opening;
• and
• a third chamber configured to form a metal layer on the substrate having the deposition resistant layer to fill the opening.