SEMICONDUCTOR DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a semiconductor device is configured to be able to suppress reduction in electric characteristics which becomes remarkable in association with miniaturization.SOLUTION: The semiconductor device is configured to comprise: a first oxide semiconductor layer formed on an insulating surface; a second oxide semiconductor layer which is formed on the first oxide semiconductor layer, and has a smaller area than that of the first oxide semiconductor layer, and entirely overlaps with the first oxide semiconductor layer; a source and a drain electrode layers which each have one surface in contact with a part of each of the first and second oxide semiconductor layers; a third oxide semiconductor layer which is formed on the first and second oxide semiconductor layers and partially overlaps with the other surfaces of the source and drain electrode layers; a gate insulating film formed on the third oxide semiconductor layer; and a gate electrode layer formed on the gate insulating film.