According to one or more embodiments, a method for manufacturing a semiconductor device comprises forming a stacked film that comprises alternating first insulating layers and second insulating layers. A first insulating film, an electric charge storage layer, a second insulating film, and a first semiconductor layer are then formed in a hole in the stacked film. The method further includes forming a first recess in the stacked film, then supplying a first gas and a deuterium gas to the first recess. The first gas comprises hydrogen and oxygen.