US Patent 7217398 Deposition reactor with precursor recycle

A reactor vessel is provided with a solvent in a supercritical PVT state for use in depositing films on a deposition substrate. A metal organic precursor is dissolved in the supercritical solvent, as is a reaction agent. A chemical reaction deposits a film, such as a metal film on a semiconducting wafer, and reaction byproducts including a ligand ensue from the chemical reaction. Effluent from the reactor vessel is submitted to a precursor-forming agent that reacts with the ligand to rejuvenate the precursor. Alternatively, the precursor-forming agent can be used for point-of-use formation of the precursor with or without recycle of reaction byproducts.