Abstract: A semiconductor device of an embodiment includes a semiconductor layer formed of a III-V group nitride semiconductor, a first silicon nitride film formed on the semiconductor layer, a gate electrode formed on the first silicon nitride film, a source electrode and a drain electrode formed on the semiconductor layer such that the gate electrode is interposed between the source electrode and the drain electrode, and a second silicon nitride film formed between the source electrode and the gate electrode and between the drain electrode and the gate electrode and having an oxygen atom density lower than that of the first silicon nitride film.

Abstract: A semiconductor device of an embodiment includes a semiconductor layer formed of a III-V group nitride semiconductor, a first silicon nitride film formed on the semiconductor layer, a gate electrode formed on the first silicon nitride film, a source electrode and a drain electrode formed on the semiconductor layer such that the gate electrode is interposed between the source electrode and the drain electrode, and a second silicon nitride film formed between the source electrode and the gate electrode and between the drain electrode and the gate electrode and having an oxygen atom density lower than that of the first silicon nitride film.

Abstract: A semiconductor device according to an embodiment includes a first GaN based semiconductor layer of a first conductive type, a second GaN based semiconductor layer of the first conductive type provided above the first GaN based semiconductor layer, a third GaN based semiconductor layer of a second conductive type provided above a part of the second GaN based semiconductor layer, a epitaxially grown fourth GaN based semiconductor layer of the first conductive type provided above the third GaN based semiconductor layer, a gate insulating film provided on the second, third, and fourth GaN based semiconductor layer, a gate electrode provided on the gate insulating film, a first electrode provided on the fourth GaN based semiconductor layer, a second electrode provided at the side of the first GaN based semiconductor layer opposite to the second GaN based semiconductor layer, and a third electrode provided on the second GaN based semiconductor layer.

Abstract: A semiconductor device of an embodiment includes a semiconductor layer formed of a III-V group nitride semiconductor, a first silicon nitride film formed on the semiconductor layer, a gate electrode formed on the first silicon nitride film, a source electrode and a drain electrode formed on the semiconductor layer such that the gate electrode is interposed between the source electrode and the drain electrode, and a second silicon nitride film formed between the source electrode and the gate electrode and between the drain electrode and the gate electrode and having an oxygen atom density lower than that of the first silicon nitride film.

Abstract: This disclosure provides a semiconductor device which includes a GaN-based semiconductor layer having a surface with an angle of not less than 0 degree and not more than 5 degrees with respect to an m-plane or an a-plane, a first electrode provided above the surface and having a first end, and a second electrode provided above the surface to space apart from the first electrode, having a second end facing the first end, and a direction of a segment connecting an arbitrary point of the first end and an arbitrary point of the second end is different from a c-axis direction of the GaN-based semiconductor layer.

Abstract: A semiconductor device according to an embodiment includes a nitride semiconductor layer, a gate electrode provided above the nitride semiconductor layer, a source electrode provided above the nitride semiconductor layer, a drain electrode provided above the nitride semiconductor layer at a side opposite to the source electrode with respect to the gate electrode, a first silicon nitride film provided above the nitride semiconductor layer between the drain electrode and the gate electrode, and a second silicon nitride film provided between the nitride semiconductor layer and the gate electrode, an atomic ratio of silicon to nitrogen in the second silicon nitride film being lower than an atomic ratio of silicon to nitrogen in the first silicon nitride film.

Abstract: A semiconductor device of an embodiment includes a semiconductor layer formed of a III-V group nitride semiconductor, a first silicon nitride film formed on the semiconductor layer, a gate electrode formed on the first silicon nitride film, a source electrode and a drain electrode formed on the semiconductor layer such that the gate electrode is interposed between the source electrode and the drain electrode, and a second silicon nitride film formed between the source electrode and the gate electrode and between the drain electrode and the gate electrode and having an oxygen atom density lower than that of the first silicon nitride film.

Abstract: A semiconductor device of one embodiment, including the semiconductor layer including a III-V group nitride semiconductor; a groove portion formed in the semiconductor layer; the gate insulating film formed at least on a bottom surface of the groove portion, the gate insulating film being a stacked film of a first insulating film and a second insulating film of which dielectric constant is higher than that of the first insulating film; the gate electrode formed on the gate insulating film; and a source electrode and a drain electrode formed on the semiconductor layer across the gate electrode, in which the second insulating film is selectively formed only under the gate electrode.