Patent ID: 9680026
Date: 2017-06-13
CPC Classifications: G02F,H01L

Claim:
1. A semiconductor device comprising: a first gate electrode over a substrate; a first insulating film over the first gate electrode; a semiconductor film over the first insulating film, the semiconductor film including a first impurity region, a second impurity region, and a channel formation region between the first impurity region and the second impurity region; a second gate electrode overlapping the first gate electrode; a source electrode electrically connected to the first impurity region; and a drain electrode electrically connected to the second impurity region, wherein the semiconductor film contains silicon, wherein a ratio of a thickness to a channel width in the channel formation region of the semiconductor film is greater than 1 and less than or equal to 10, and wherein, in a cross section in a channel width direction, the second gate electrode extends beyond a first side surface of the semiconductor film, a top surface of the semiconductor film, and a second side surface of the semiconductor film.