SEMICONDUCTOR DEVICE AND SEMICONDUCTOR DEVICE MANUFACTURING METHOD

摘要

PROBLEM TO BE SOLVED: To provide a semiconductor device having a configuration which can inhibit deterioration in electric characteristics which becomes prominent in association with microfabrication.SOLUTION: A semiconductor device comprises: a first oxide semiconductor film on an insulating surface; a second oxide semiconductor film on the first oxide semiconductor film; a source electrode and a drain electrode, which contact lateral faces of the first oxide semiconductor film, lateral faces of the second oxide semiconductor film and a top face of the second oxide semiconductor film; a third oxide semiconductor film on the second oxide semiconductor film, the source electrode and the drain electrode; a gate insulation film on the third oxide semiconductor film; and a gate electrode which contacts the gate insulation film and faces the top face and the lateral faces of the second oxide semiconductor film. Note that, it is preferable that a third length obtained by reduction of a second length between the source electrode and the drain electrode in a channel length direction from a first length of the second oxide semiconductor film in a channel length be not less than 0.2 times and not more than 2.0 times longer than the second length.