SUBSTRATE PROCESSING METHOD AND SUBSTRATE PROCESSING APPARATUS

A substrate processing method includes housing, in a processing container, a substrate having an insulating film on a surface of the substrate; exposing the insulating film to plasma generated from a gas including deuterium gas in a state where the substrate housed in the processing container is maintained at a first temperature, to introduce deuterium into the insulating film; and 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.