Patent ID: 9159838
Filing Date: 2015-10-13
Classification: H01L

Abstract:
1. A semiconductor device comprising: a gate electrode; a gate insulating film; a first oxide semiconductor film overlapping with the gate electrode with the gate insulating film positioned between the first oxide semiconductor film and the gate electrode; a second oxide semiconductor film over the first oxide semiconductor film; a third oxide semiconductor film over the second oxide semiconductor film; and a source electrode and a drain electrode being in contact with the third oxide semiconductor film and the gate insulating film, wherein an end portion of the second oxide semiconductor film is spaced from an end portion of the source electrode or the drain electrode in a region overlapping with the second oxide semiconductor film in a channel width direction, wherein a width of the second oxide semiconductor film in the channel width direction is larger than a width of the source electrode or the drain electrode in the channel width direction, and wherein an energy level of a bottom of a conductive band of the second oxide semiconductor film is lower than an energy level of a bottom of a conductive band of the first oxide semiconductor film and an energy level of a bottom of a conductive band of the third oxide semiconductor film.