Patent ID: 8211809

Claim:
A method of producing a semiconductor device in which at least one pillar-shaped semiconductor layer is provided on a semiconductor substrate, and a dielectric film is provided on respective surfaces of the semiconductor substrate and the at least one pillar-shaped semiconductor layer, the method comprising: (a) forming a first gate conductive film to cover respective surfaces of the at least one pillar-shaped semiconductor layer and a hard mask formed on a top of the at least one pillar-shaped semiconductor layer; (b) after step (a), flattening an upper surface of the first gate conductive film, using the hard mask as a stopper; (c) after step (b), forming a second gate conductive film on the flattened surface of the first gate conductive film; (d) after step (c), anisotropically etching the second gate conductive film; (e) monitoring an intensity of plasma emission emitted from the second gate conductive film during the etching to detect an end-point at which the etching of the second gate conductive film needs to end, based on a change in the plasma emission intensity; (f) after step (e), anisotropically etching the first gate conductive film; and (g) determining an end-point at which the etching of the first gate conductive film needs to end, using an etching rate of the first gate conductive film determined with a relative ratio between the etching rate of the first gate conductive film and an etching rate of the second gate conductive film calculated from a film thickness of the second gate conductive film and a time taken from a beginning to an end of the etching of the second gate conductive film.