主权项 |
1. A semiconductor device comprising:
a gate electrode over a substrate, the gate electrode comprising copper; a first insulating film over the gate electrode, the first insulating film comprising silicon nitride; a second insulating film over the first insulating film, the second insulating film comprising silicon oxide; an oxide semiconductor film over the second insulating film, the oxide semiconductor film comprising indium and oxygen; a first film over the oxide semiconductor film, the first film comprising oxide; a second film over the oxide semiconductor film, the second film comprising oxide; a source electrode over the oxide semiconductor film with the first film interposed therebetween; a drain electrode over the oxide semiconductor film with the second film interposed therebetween; a third insulating film over the oxide semiconductor film, the source electrode, and the drain electrode, the third insulating film comprising silicon oxide; a fourth insulating film over the third insulating film, the fourth insulating film comprising silicon nitride; and a pixel electrode over the fourth insulating film, the pixel electrode electrically connected to one of the source electrode and the drain electrode, wherein the oxide semiconductor film comprises a first end portion, a second end portion, a depressed portion overlapping with the gate electrode and between the first end portion and the second end portion, and a portion between the depressed portion and the first end portion, wherein one of the first film and the second film is in contact with a top surface of the portion, and each of the first film and the second film is not in contact with a top surface of the depressed portion, and a top surface of the first end portion, wherein a thickness of the portion is larger than a thickness of the depressed portion and larger than a thickness of the first end portion, wherein a first gap between the first film and the second film is smaller than a second gap between the source electrode and the drain electrode, wherein the first gap is a distance between an upper end portion of the first film and an upper end portion of the second film, and the second gap is a distance between a lower end portion of the source electrode and a lower end portion of the drain electrode, and wherein the third insulating film is in contact with the depressed portion. |