Processes and systems for engineering a copper surface for selective metal deposition

A method of preparing a substrate surface of a substrate to selectively deposit a thin layer of a cobalt-alloy material on a copper surface of a copper interconnect of the substrate in an integrated system to improve electromigration performance of the copper interconnect, comprising:

• removing contaminants and metal oxides from the substrate surface in a wet process module connected to a first transfer module, which is a lab-ambient transfer module of the integrated system;
• after removing contaminants and metal oxides, moving the substrate from the wet process module to the lab-ambient transfer module;
• moving the substrate from the lab-ambient transfer module to a second transfer module, which is a vacuum transfer module;
• moving the substrate from the vacuum transfer module to a plasma module connected to the vacuum transfer module;
• reconditioning the copper surface of the copper interconnect using a reducing environment, after removing contaminants and metal oxides, in the plasma module connected to the vacuum transfer module of the integrated system;
• after reconditioning the copper surface, moving the substrate from the plasma module to the vacuum transfer module;
• moving the substrate from the vacuum transfer module to a third transfer module, which is a controlled-ambient transfer module;
• moving the substrate from the controlled-ambient transfer module to a wet electroless deposition process module connected to the controlled-ambient transfer module;
• selectively depositing the thin layer of cobalt-alloy material on the copper surface of the copper interconnect, after reconditioning the substrate surface, in the wet-electroless deposition process module;
• wherein one or more process modules and the transfer modules of the integrated system being filled with inert gas to reduce oxygen exposure during transfers of the substrate within the integrated system, the transfers of the substrate include transfers between the transfer modules of the integrated system, the wet electroless deposition process module being filled with the inert gas to maintain an oxygen level in the processing environment that is lower than ambient, and transfers in the inert gas filled transfer modules protects the copper surface from oxidation after the contaminants and the metal oxides are removed from the substrate surface and before the thin layer of cobalt-alloy material is selectively deposited on the copper surface;
• wherein the wet electroless deposition process module provides for a dry-in/dry-out processing of the substrate, the substrate goes in and comes out of the wet electroless deposition process module in a dry state, the wet electroless deposition process module providing for rinse and dry operations without wet robotic transfer of the substrate to a separate rinse-dry module;
• wherein reconditioning the substrate surface converts surface copper oxides to substantially copper, and after reconditioning the substrate surface, the substrate is transferred and processed in a controlled environment to minimize the formation of copper oxide over the copper surface;
• wherein after reducing the copper surface, the substrate is transferred and processed with limited exposure to oxygen to enable the thin layer of the cobalt-alloy material to be selectively deposited on the copper surface, and wherein the first transfer module, the second transfer module and the third transfer modules are distinct, and wherein after electroless deposition the substrate is transferred from the electroless chamber to the controlled ambient transfer module, and from the controlled ambient transfer module, the substrate is transferred to the vacuum transfer module, and then from the vacuum transfer module the substrate is transferred to the lab ambient transfer module.