Method of manufacturing semiconductor device, substrate processing method and substrate processing apparatus

A substrate processing method comprising:

• forming an oxide film having a specific film thickness on a substrate by alternately repeating:
• forming a specific element-containing layer on the substrate by supplying a source gas containing a specific element, to the substrate housed in a processing chamber and heated to a first temperature;
• and
• changing the specific element-containing layer formed on the substrate, to an oxide layer by supplying a reactive species containing oxygen to the substrate heated to the first temperature in the processing chamber under a pressure of less than atmospheric pressure, the reactive species being generated by causing a reaction between an oxygen-containing gas and a hydrogen-containing gas in a pre-reaction chamber under a pressure of less than atmospheric pressure and heated to a second temperature higher than the first temperature.

A substrate processing apparatus, comprising:

• a processing chamber configured to house a substrate and process the substrate;
• a first heating source configured to heat the substrate to a first temperature in the processing chamber;
• a pre-reaction chamber configured to cause a reaction among a plurality of kinds of gases;
• a second heating source configured to heat an inside of the pre-reaction chamber to a second temperature;
• a source gas supply system configured to supply a source gas containing a specific element into the processing chamber;
• an oxygen-containing gas supply system configured to supply an oxygen-containing gas into the pre-reaction chamber;
• a hydrogen-containing gas supply system configured to supply a hydrogen-containing gas into the pre-reaction chamber;
• a piping part configured to connect the pre-reaction chamber and the processing chamber;
• a pressure adjustment part configured to adjust pressures in the processing chamber and the pre-reaction chamber;
• and
• a control part configured to control the first heating source, the second heating source, the source gas supply system, the oxygen-containing gas supply system, the hydrogen-containing gas supply system, and the pressure adjustment part, so that an oxide film having a specific film thickness is formed on the substrate, by alternately repeating a process of forming a specific element-containing layer on the substrate by supplying the source gas to the substrate housed in the processing chamber and heated to the first temperature;
• and a process of changing the specific element-containing layer formed on the substrate, to an oxide layer by supplying a reactive species containing oxygen to the substrate heated to the first temperature in the processing chamber under a pressure of less than atmospheric pressure, the reactive species being generated by causing a reaction between an oxygen-containing gas and a hydrogen-containing gas in the pre-reaction chamber under a pressure of less than atmospheric pressure and heated to the second temperature higher than the first temperature.