Film-forming method, film-forming apparatus, and oxidation method

A film-forming apparatus for forming an oxide film on a substrate, comprising:

• a chamber in which the substrate is accommodated;
• a stage provided inside the chamber and configured to place the substrate thereon;
• a first heater configured to heat the substrate placed on the stage;
• a gas supplier configured to supply a raw material gas for forming the oxide film on the substrate, a hydrogen gas, and an oxygen gas;
• an exhauster configured to exhaust an inside of a chamber;
• a second heater configured to preheat at least the hydrogen gas and the oxygen gas;
• and
• a controller configured to control the first heater, the second heater, the gas supplier, and the exhauster,
• wherein the gas supplier includes at least one filling tank provided in at least one pipe configured to supply the hydrogen gas and the oxygen gas therethrough and in which the hydrogen gas and the oxygen gas are filled, and a valve provided at a downstream side of the filling tank in a gas supply path,
• wherein the controller controls the gas supplier and the second heater to:
• repeat adsorbing the raw material gas onto the substrate by supplying the raw material gas into the chamber and oxidizing the raw material gas adsorbed onto the substrate with oxygen-containing radicals produced by supplying the hydrogen gas and the oxygen gas into the chamber while preheating the hydrogen gas and the oxygen gas by the second heater;
• and
• when supplying at least one of the hydrogen gas and the oxygen gas, supply the at least one of the hydrogen gas and the oxygen gas from the filling tank such that a supply partial pressure is relatively high at an initial supply stage and gradually decreases over time by filling the filling tank with the at least one of the hydrogen gas and the oxygen gas at a pressure higher than an internal pressure of the chamber and opening the valve.

A method of performing an oxidation process on a substrate inside a chamber, the method comprising:

• supplying a hydrogen gas and an oxygen gas into the chamber while preheating the hydrogen gas and the oxygen gas;
• and
• oxidizing a surface of the substrate with oxygen-containing radicals produced by the preheated hydrogen gas and the preheated oxygen gas,
• wherein, when supplying at least one of the hydrogen gas and the oxygen gas, a supply partial pressure of the at least one of the hydrogen gas and the oxygen gas is changed to be relatively high at an initial supply stage and gradually decrease over time.