Metal oxide diffusion barriers

A system for forming an interconnect structure, or a portion thereof, on a substrate, the system comprising:

• a. a first processing chamber;
• and
• b. a controller having at least one processor and a memory, wherein the at least one processor and the memory are communicatively connected with one another, and the memory stores computer-executable instructions for controlling the at least one processor to cause:
• (i) receiving the substrate in the first processing chamber, wherein the substrate comprises a dielectric material with recessed features formed in the dielectric material, wherein the interconnect structure is to be formed in the recessed features, and wherein the dielectric material is exposed within the recessed features;
• (ii) exposing the substrate to a plasma in the first processing chamber to thereby modify a top surface of the dielectric material;
• (iii) after (ii), forming a metal oxide barrier layer on the modified top surface of the dielectric material, wherein the metal oxide barrier layer is formed, at least in part, through atomic layer deposition (ALD) and/or chemical vapor deposition (CVD);
• and
• (iv) after (iii), exposing the substrate to a reducing gas or a reducing plasma generated from the reducing gas, thereby reducing a top surface of the metal oxide barrier layer and forming an in-situ metal liner on the metal oxide barrier layer.