Metal-on-metal deposition methods for filling a gap feature on a substrate surface

A method of bottom-up filling a gap feature on a surface of a substrate, comprising

• surface cleaning a substrate with a gap feature having sidewalls with dielectric surface and a bottom surface with a metal film to remove metal oxides from the metal film;
• after the surface cleaning, providing the substrate in a reaction chamber;
• heating the substrate to a substrate temperature greater than 350° C.;
• contacting the substrate with a molybdenum precursor comprising one or more of MoCl5 and MoCl4 by periodically pulsing the molybdenum precursor;
• contacting the substrate with a reducing agent, wherein contacting the substrate with the reducing agent comprises continuously providing the reducing agent during the step of contacting the substrate with the molybdenum precursor;
• and
• repeating the contacting steps until a molybdenum film is formed on the metal film on the bottom surface of the gap feature, wherein the molybdenum film is formed with a selectivity of at least 50:1 between the metal film and the dielectric surface.

A method for selectively depositing a molybdenum film on a semiconductor device structure, comprising:

• providing a device structure in a reaction chamber, wherein the device structure comprises a substrate including a dielectric surface and a metal surface;
• partially forming a molybdenum film selectively on the metal surface with a cyclical chemical vapor deposition (cyclical CVD) process, wherein a unit cycle of the cyclical chemical vapor deposition process comprises:
• providing a molybdenum precursor in the reaction chamber;
• purging the molybdenum precursor from the reaction chamber;
• and
• providing a reactant in the reaction chamber, wherein the reactant comprises a reducing agent;
• repeating the partially forming the molybdenum film step until the molybdenum film has a thickness greater than 200 Å and wherein a thickness of molybdenum grown on the dielectric surface is substantially 0 Å.