Process for low resistance metal cap

A method comprising the steps of:

• providing a substrate with exposed metal and dielectric surfaces;
• performing a reducing plasma process on the metal and dielectric surfaces;
• and
• transferring the substrate in an inert or reducing ambient to a chamber that is used for selective metal layer deposition,
• wherein the selective metal deposition includes deposition of at least one layer of a cobalt alloy, and the at least one layer of cobalt alloy includes:
• a first layer of an alloy comprising at least about 95 atom % cobalt;
• and
• a second layer of an alloy comprising at most about 95 atom % cobalt.

A substrate processed by a method comprising the steps of

• providing a substrate with exposed metal and dielectric surfaces;
• performing a reducing plasma process on the metal and;
• dielectric surfaces;
• and
• transferring the substrate in an inert or reducing ambient to a chamber that is used for selective metal layer deposition,
• wherein the selective metal deposition includes deposition of at least ne layer of a cobalt alloy that includes:
• a first layer of an ahoy comprising at least about 95 atom % cobalt;
• and
• a second layer of an alloy comprising at most about 95 atom % cobalt.

A method comprising the steps of:

• providing a substrate with exposed metal and dielectric surfaces;
• performing a reducing plasma process on the metal and dielectric surfaces, the reducing plasma process including exposing the substrate to a downstream plasma comprising H2 ions or a forming gas;
• transferring the substrate in a, reducing ambient to a chamber after the reducing plasma process;
• performing a selective metal deposition in the chamber alter the transferring step, the selective metal deposition including deposition of at least one layer of a cobalt alloy.