Metallization surface treatment for integrated circuit packages

A system comprising:

• a first integrated circuit (IC) die;
• a second IC die;
• and
• an integrated circuit (IC) device package, comprising:
• a metallization line interconnecting the first IC die to the second IC die, wherein the metallization line comprises predominantly Cu, and a first amount of N proximal to a sidewall surface of the line that is greater than a second amount of N within an interior of the metallization line, distal from the sidewall surface.

A method of fabricating an integrated circuit (IC) device package, the method comprising:

• receiving a substrate comprising a dielectric material;
• forming a metallization feature over the dielectric material;
• introducing nitrogen into the metallization feature;
• and
• depositing additional dielectric material over the metallization feature.