Patent ID: 8860021

Claim:
A semiconductor element comprising: an oxide semiconductor layer comprising: a first low-resistance region; a second low-resistance region; and a channel formation region between the first low-resistance region and the second low-resistance region, wherein the channel formation region comprises a first side surface and a second side surface opposite to the first side surface; a first insulating film over the oxide semiconductor layer; a gate electrode facing a top surface, the first side surface, and the second side surface of the channel formation region with the first insulating film interposed therebetween; a second insulating film over the gate electrode; a first electrode over the second insulating film; and a second electrode over the second insulating film, wherein the first low-resistance region and the second low-resistance region each have a resistance lower than the channel formation region, and wherein the first electrode is in contact with the first low-resistance region through a first opening in the first insulating film and the second insulating film, and wherein the second electrode is in contact with the second low-resistance region through a second opening in the first insulating film and the second insulating film.