Method for manufacturing semiconductor device

摘要

An object is to provide a method for manufacturing a semiconductor device including an oxide semiconductor and having improved electric characteristics. The semiconductor device includes an oxide semiconductor film, a gate electrode overlapping the oxide semiconductor film, and a source electrode and a drain electrode electrically connected to the oxide semiconductor film. The method includes the steps of forming a first insulating film including gallium oxide over and in contact with the oxide semiconductor film; forming a second insulating film over and in contact with the first insulating film; forming a resist mask over the second insulating film; forming a contact hole by performing dry etching on the first insulating film and the second insulating film; removing the resist mask by ashing using oxygen plasma; and forming a wiring electrically connected to at least one of the gate electrode, the source electrode, and the drain electrode through the contact hole.

主权项

1. A method for manufacturing a transistor comprising an oxide semiconductor layer, at least one of a source electrode and a drain electrode electrically connected to the oxide semiconductor layer, a gallium oxide layer, a gate electrode, and a protective insulating film, the method comprising the steps of:
forming the one of the source electrode and the drain electrode over the oxide semiconductor layer; forming the gallium oxide layer over the one of the source electrode and the drain electrode, the gallium oxide layer being on and in contact with the oxide semiconductor layer; forming the gate electrode over the gallium oxide layer; forming the protective insulating film over the gallium oxide layer and the gate electrode; forming a resist mask over the protective insulating film; and forming a contact hole by dry etching the protective insulating film and the gallium oxide layer using the resist mask, wherein a width of the contact hole in the gallium oxide layer is smaller than a width of the contact hole in the protective insulating film, and wherein the contact hole includes a stepped shape.