Patent attributes
To form a microcrystalline semiconductor with high quality which can be directly formed at equal to or less than 500° C. over a large substrate with high productivity without decreasing a deposition rate. In addition, to provide a photoelectric conversion device which employs the microcrystalline semiconductor as a photoelectric conversion layer. A reactive gas containing helium is supplied to a treatment chamber which is surrounded by a plurality of juxtaposed waveguides and a wall, the pressure in the treatment chamber is maintained at an atmospheric pressure or a subatmospheric pressure, microwave is supplied to a space sandwiched between the juxtaposed waveguides to generate plasma, and a photoelectric conversion layer of a microcrystalline semiconductor is deposited over a substrate which is placed in the treatment chamber.