Method of making interconnect structure

A method semiconductor device, comprising:

• providing a Si-containing layer;
• forming a metallic contact layer over said Si-containing layer, said contact layer including a metallic element;
• forming a forming a barrier layer over said Si-containing layer, said barrier layer comprising a compound including said metallic element;
• forming a metallic nucleation_seed layer over said barrier layer, said nucleation seed layer including said metallic element;
• and
• forming a metallic interconnect layer over said nucleation seed layer,
• wherein said contact layer, barrier layer and said nucleation_seed layer are formed in the same chamber without exposing said semiconductor device to the ambient atmosphere.