Method of manufacturing semiconductor device

摘要

A resist layer (46a) including a thick film section (47a), which is relatively thick, at one side thereof, and a thin film section (47b), which is relatively thin, at the other side thereof is formed using a multiple-tone mask. A gate electrode (15a) is formed at a place where it will be provided on a semiconductor layer (12a) so as to be narrower than the resist layer (46a), by executing isotropic etching to a conductive film (44) formed in advance using the resist layer (46a) as a mask, in order to form overhang portions (48) on the resist layer (46a) at both sides of the gate electrode (15a). Then, the entire thin film section (47b) is removed, the thick film section (47a) is made thinner, and impurities are implanted into the semiconductor layer (12a) using the remaining resist layer (46a) and the gate electrode (15a) as masks.

主权项

1. A manufacturing method for a semiconductor device, comprising:
a semiconductor layer forming step of forming a semiconductor film on a base substrate and patterning the semiconductor film to form a semiconductor layer; a gate insulating film forming step of forming a gate insulating film so as to cover the semiconductor layer; a conductive film forming step of forming, on the gate insulating film, a conductive film that is used to form gate electrodes; a photosensitive resin film forming step of forming a photosensitive resin film on the conductive film; a photosensitive resin film patterning step of patterning the photosensitive resin film by exposure such that an amount of light radiated onto the photosensitive resin film is controlled by using a multiple gradation mask and then developing is performed on the photosensitive resin film, thereby forming a resist layer over a portion of the semiconductor layer, the resist layer having a thick film portion on one side, and a thin film portion that is thinner than the thick film portion on another side; a conductive film patterning step of patterning the conductive film by isotropic etching using the resist layer as a mask and thereby forming a gate electrode that is narrower than the resist layer over the semiconductor layer, providing the resist layer with overhang portions that hang over both sides of the gate electrode in an eave-shape; a thin film portion removal step of removing the thin film portion, and thereby shaping the resist layer having the overhang portions such that an overhang portion hangs over only one side of the gate electrode; and an impurity implantation step of, after the thin film removal step, implanting a conductive impurity of a conductivity type different from a conductivity type of the semiconductor layer to the semiconductor layer using the resist layer as a mask, to form impurity implanted regions in the semiconductor layer respectively on both sides of a portion corresponding in position to the gate electrode, the impurity implanted region on one side of the gate electrode being formed with a gap therefrom corresponding to the overhang portion.