Superconformal molybdenum via fill by use of deposition gradient control

A method of metal gap fill deposition on a semiconductor substrate, comprising:

• forming a liner layer on a surface of a feature by providing a first dosage and a second dosage of a first metal-containing precursor comprising molybdenum oxychloride to a processing chamber, wherein:
• the feature comprises a feature formed in a surface of the semiconductor substrate,
• the feature comprises an opening that is defined by a capping layer and side walls, wherein the side walls comprise a dielectric material, and
• the liner layer is formed over the side walls and the capping layer;
• and
• depositing a metal gap fill material over the liner layer to fill the feature formed in the surface of the semiconductor substrate by providing a second metal-containing precursor comprising molybdenum chloride and a hydrogen-containing precursor comprising H2 to the processing chamber.