Method of plasma-assisted cyclic deposition using ramp-down flow of reactant gas

摘要

A method is for forming a nitride or oxide film by plasma-assisted cyclic deposition, one cycle of which includes: feeding a first reactant, a second reactant, and a precursor to a reaction space where a substrate is placed, wherein the second reactant flows at a first flow ratio wherein a flow ratio is defined as a ratio of a flow rate of the second reactant to a total flow rate of gases flowing in the reaction space; and stopping feeding the precursor while continuously feeding the first and second reactants at a flow ratio which is gradually reduced from the first flow ratio to a second flow ratio while applying RF power to the reaction space to expose the substrate to a plasma. The second reactant is constituted by a hydrogen-containing compound or oxygen-containing compound.