Substrate processing method and substrate processing apparatus for controlling introduction into insulating film

A substrate processing apparatus comprising:

• a processing container;
• a gas supply configured to supply gas into the processing container;
• a plasma generator configured to generate plasma from the gas;
• and
• a controller configured to control the gas supply and the plasma generator to execute
• housing, in the processing container, a substrate having an insulating film on a surface of the substrate;
• supplying deuterium gas into the processing container in which the substrate is housed, the deuterium gas being the gas;
• generating the plasma from the deuterium gas;
• exposing the insulating film to the plasma in a state where the substrate housed in the processing container is maintained at a first temperature, to introduce deuterium into the insulating film;
• extinguishing plasma that is generated by introducing the deuterium into the insulating film;
• and
• after extinguishing the plasma, heat-treating the insulating film without exposing the insulating film to the plasma in a state where the substrate housed in the processing container is controlled to be at a second temperature that is different from the first temperature, to adjust concentration of the deuterium introduced into the insulating film.