Abstract: The semiconductor device of this invention includes an active region formed from a group III nitride semiconductor grown on a substrate and an insulating oxide film formed in a peripheral portion of the active region by oxidizing the group III nitride semiconductor. On the active region, a gate electrode in Schottky contact with the active region extending onto the insulating oxide film and having an extended portion on the insulating oxide film is formed, and ohmic electrodes respectively serving as a source electrode and a drain electrode are formed with space from side edges along the gate length direction of the gate electrode.

Abstract: A semiconductor device has an active region composed of a group III-V nitride semiconductor and ohmic electrodes and a gate electrode each formed on the active region. The active region has an entire surface thereof exposed to a plasma such that a surface potential for electrons therein is lower than in the case where the entire surface is not exposed to the plasma.

Abstract: The semiconductor device of this invention includes an active region formed from a group III nitride semiconductor grown on a substrate and an insulating oxide film formed in a peripheral portion of the active region by oxidizing the group III nitride semiconductor. On the active region, a gate electrode in Schottky contact with the active region extending onto the insulating oxide film and having an extended portion on the insulating oxide film is formed, and ohmic electrodes respectively serving as a source electrode and a drain electrode are formed with space from side edges along the gate length direction of the gate electrode.

Abstract: An insulating-gate semiconductor device has a first nitride semiconductor layer formed over a substrate and an insulating oxidation layer obtained by oxidizing a second nitride semiconductor layer formed on the first nitride semiconductor layer. A gate electrode is formed on the insulating oxidation layer.

Abstract: An active region formed of a Group III nitride semiconductor is formed on a substrate. Then, an electrode is formed on the active region and a protective insulating film is formed on a part of the active region located in the peripheral portion of the electrode by oxidizing the Group III nitride semiconductor.

Abstract: A semiconductor device has an active region composed of a group III-V nitride semiconductor and ohmic electrodes and a gate electrode each formed on the active region. The active region has an entire surface thereof exposed to a plasma such that a surface potential for electrons therein is lower than in the case where the entire surface is not exposed to the plasma.

Abstract: A semiconductor device has an active region composed of a group III–V nitride semiconductor and ohmic electrodes and a gate electrode each formed on the active region. The active region has an entire surface thereof exposed to a plasma such that a surface potential for electrons therein is lower than in the case where the entire surface is not exposed to the plasma.

Abstract: A buffer layer, an undoped gallium nitride layer, and an n-type gallium nitride active layer are formed on a sapphire substrate. Ohmic contacts and a Schottky contact are then formed on the n-type gallium nitride active layer as a source contact, a drain contact and a gate contact, respectively. The Schottky contact is a copper alloy, such as palladium copper, in which the content by weight of copper is 5%.

Abstract: A semiconductor device has a first semiconductor layer composed of a group III–V nitride, an oxide film formed by oxidizing a second semiconductor layer composed of a group III–V nitride to be located on the gate electrode formation region of the first semiconductor layer, an insulating film formed on the oxide film to have a composition different from the composition of the oxide film, and a gate electrode formed on the insulating film.

Abstract: In a method for fabricating a semiconductor device, a first semiconductor layer of aluminum gallium nitride is first formed on a substrate, and a protection film containing silicon is then formed on the first semiconductor layer in such a manner that a device-isolation region is uncovered. Thereafter, the method further includes the step of heat-treating the first semiconductor layer in an oxidizing atmosphere whose temperature is adjusted to be within a range of 950° C. or more and 1050° C. or less.

Abstract: A semiconductor device includes: a substrate; a buffer layer including GaN formed on the substrate, wherein: surfaces of the buffer layer are c facets of Ga atoms; a channel layer including GaN or InGaN formed on the buffer layer,wherein: surfaces of the channel layer are c facets of Ga or In atoms; an electron donor layer including AlGaN formed on the channel layer, wherein: surfaces of the electron donor layer are c facets of Al or Ga atoms; a source electrode and a drain electrode formed on the electron donor layer; a cap layer including GaN or InGaAlN formed between the source electrode and the drain electrode, wherein: surfaces of the cap layer are c facets of Ga or In atoms and at least a portion of the cap layer is in contact with the electron donor layer; and a gate electrode formed at least a portion of which is in contact with the cap layer.

Abstract: The semiconductor device of the present invention includes: a gallium nitride (GaN) compound semiconductor layer; and a Schottky electrode formed on the GaN compound semiconductor layer, wherein the Schottky electrode contains silicon.

Abstract: A semiconductor device includes: a substrate; a buffer layer including GaN formed on the substrate, wherein: surfaces of the buffer layer are c facets of Ga atoms; a channel layer including GaN or InGaN formed on the buffer layer, wherein: surfaces of the channel layer are c facets of Ga or In atoms; an electron donor layer including AlGaN formed on the channel layer, wherein: surfaces of the electron donor layer are c facets of Al or Ga atoms; a source electrode and a drain electrode formed on the electron donor layer; a cap layer including GaN or InGaAlN formed between the source electrode and the drain electrode, wherein: surfaces of the cap layer are c facets of Ga or In atoms and at least a portion of the cap layer is in contact with the electron donor layer; and a gate electrode formed at least a portion of which is in contact with the cap layer.

Abstract: A semiconductor device has a first semiconductor layer composed of a group III-V nitride, an oxide film formed by oxidizing a second semiconductor layer composed of a group III-V nitride to be located on the gate electrode formation region of the first semiconductor layer, an insulating film formed on the oxide film to have a composition different from the composition of the oxide film, and a gate electrode formed on the insulating film.

Abstract: A semiconductor device includes: a substrate; a buffer layer including GaN formed on the substrate, wherein: surfaces of the buffer layer are c facets of Ga atoms; a channel layer including GaN or InGaN formed on the buffer layer, wherein: surfaces of the channel layer are c facets of Ga or In atoms; an electron donor layer including AlGaN formed on the channel layer, wherein: surfaces of the electron donor layer are c facets of Al or Ga atoms; a source electrode and a drain electrode formed on the electron donor layer; a cap layer including GaN or InGaAlN formed between the source electrode and the drain electrode, wherein: surfaces of the cap layer are c facets of Ga or In atoms and at least a portion of the cap layer is in contact with the electron donor layer; and a gate electrode formed at least a portion of which is in contact with the cap layer.

Abstract: The semiconductor device of the present invention includes: a gallium nitride (GaN) compound semiconductor layer; and a Schottky electrode formed on the GaN compound semiconductor layer, wherein the Schottky electrode contains silicon.

Abstract: A semiconductor device has an active region composed of a group III-V nitride semiconductor and ohmic electrodes and a gate electrode each formed on the active region. The active region has an entire surface thereof exposed to a plasma such that a surface potential for electrons therein is lower than in the case where the entire surface is not exposed to the plasma.

Abstract: The semiconductor device of the present invention includes: a gallium nitride (GaN) compound semiconductor layer; and a Schottky electrode formed on the GaN compound semiconductor layer, wherein the Schottky electrode contains silicon.

Abstract: A semiconductor device has a first semiconductor layer composed of a group III-V nitride, an oxide film formed by oxidizing a second semiconductor layer composed of a group III-V nitride to be located on the gate electrode formation region of the first semiconductor layer, an insulating film formed on the oxide film to have a composition different from the composition of the oxide film, and a gate electrode formed on the insulating film.

Abstract: In a method for fabricating a semiconductor device, a first semiconductor layer of aluminum gallium nitride is first formed on a substrate, and a protection film containing silicon is then formed on the first semiconductor layer in such a manner that a device-isolation region is uncovered. Thereafter, the method further includes the step of heat-treating the first semiconductor layer in an oxidizing atmosphere whose temperature is adjusted to be within a range of 950° C. or more and 1050 ° C. or less.