Abstract: A first insulating film in contact with an oxide semiconductor film and a second insulating film are stacked in this order over an electrode film of a transistor including the oxide semiconductor film, an etching mask is formed over the second insulating film, an opening portion exposing the electrode film is formed by etching a portion of the first insulating film and a portion of the second insulating film, the opening portion exposing the electrode film is exposed to argon plasma, the etching mask is removed, and a conductive film is formed in the opening portion exposing the electrode film. The first insulating film is an insulating film whose oxygen is partly released by heating. The second insulating film is less easily etched than the first insulating film and has a lower gas-permeability than the first insulating film.

Abstract: The object is to improve the conversion efficiency of a photoelectric conversion device. This object can be achieved by a photoelectric conversion device including an electrode and a semiconductor layer which is provided on one main surface of the electrode and contains a I-III-VI group compound semiconductor, wherein the semiconductor layer includes a connection layer that is located at a position on the one main surface side of the electrode and has a tendency that, the closer to the one main surface, the greater a quotient obtained by dividing an amount of substance of a I-B group element by an amount of substance of a III-B group element becomes.