SEMICONDUCTOR DEVICE

A semiconductor device according to an embodiment, includes a source electrode, a drain electrode arranged apart from the source electrode, an oxide semiconductor film, a gate dielectric film, and a gate electrode. The oxide semiconductor film is arranged below the source electrode and the drain electrode to connect the source electrode and the drain electrode. The gate dielectric film is formed below the oxide semiconductor film such that a thickness below at least one of the source electrode and the drain electrode is made thinner than a thickness below a channel region of the oxide semiconductor film between the source electrode and the drain electrode. The gate electrode is arranged below the gate dielectric film and formed in a position where one of portions of the gate electrode overlaps with the source electrode and another one of the portions of the gate electrode overlaps with the drain electrode.