A silicon carbide single crystal has a positive correlation between a temperature and an electric resistivity in a range from room temperature to 400° C., has an electric resistivity of at least 1×10.sup.7 Ω.Math.cm in the range from room temperature to 400° C., exhibits electric conduction by holes while no significant electric conduction properties by electrons are observed regarding electric conduction at room temperature, and has a concentration of a transition element of 1×10.sup.17/cm.sup.3 or less.

A silicon carbide single crystal has a positive correlation between a temperature and an electric resistivity in a range from room temperature to 400° C., has an electric resistivity of at least 1×10.sup.7 Ω.Math.cm in the range from room temperature to 400° C., exhibits electric conduction by holes while no significant electric conduction properties by electrons are observed regarding electric conduction at room temperature, and has a concentration of a transition element of 1×10.sup.17/cm.sup.3 or less.

A solid-state relay having favorable electrical characteristics is provided. The solid-state relay includes a first circuit and a second circuit. The first circuit includes a first light-emitting element. The second circuit includes a first light-receiving element, a memory, and a first switch. The memory includes a second switch. The second switch includes a second semiconductor layer. The first switch and the first light-emitting element are formed using a first semiconductor layer. The first semiconductor layer and the second semiconductor layer contain gallium, and the second semiconductor layer further contains oxygen. On or off of the first light-emitting element is controlled by a first signal supplied to the first circuit. First data, which is generated when the first light-receiving element converts light emitted by the first light-emitting element into voltage, is supplied to the memory. Conduction or non-conduction of the first switch is controlled by the first data stored in the memory.

An electrical device in which an interface layer is disposed in between and in contact with a conductor and a semiconductor.

An electrical device in which an interface layer is disposed in between and in contact with a conductor and a semiconductor.

A semiconductor device includes a source electrode and a drain electrode located over a surface of a semiconductor layer including an electron transit layer and an electron supply layer. A gate electrode is located between the source electrode and the drain electrode. A first diamond layer is located between the source electrode and the drain electrode over the surface with an insulating film therebetween. A second diamond layer is located directly on the surface between the gate electrode and the drain electrode. Of heat generated by the semiconductor layer of the semiconductor device in operation, heat on the side of the electrode on which a relatively strong electric field is applied is efficiently transferred to the second diamond layer. The semiconductor device achieves an excellent heat dissipation property from the semiconductor layer and effectively suppresses overheating and a failure and degradation of the characteristics due to the overheating.

There is provided a structure manufacturing method, including: preparing an etching target with at least one surface comprising group III nitride; then in a state where the etching target is immersed in an etching solution containing peroxodisulfate ions; irradiating the surface of the etching target with light through the etching solution, and generating sulfate ion radicals from the peroxodisulfate ions and generating holes in the group III nitride, thereby etching the group III nitride, wherein in the etching of the group III nitride, the etching solution remains acidic during a period for etching the group III nitride by making the etching solution acidic at a start of etching the group III nitride, and the etching is performed, with a resist mask formed on the surface.

A first raw material solution containing at least aluminum is atomized to generate first atomized droplets and a second raw material solution containing at least gallium and a dopant is atomized to generate second atomized droplets, and subsequently, the first atomized droplets are carried into a film forming chamber using a first carrier gas and the second atomized droplets are carried into the film forming chamber using a second carrier gas, and then the first atomized droplets and the second atomized droplets are mixed in the film forming chamber, and the mixed atomized droplets are thermally reacted in the vicinity of a surface of the base to form an oxide semiconductor film on the base, the oxide semiconductor film including, as a major component, a metal oxide containing at least aluminum and gallium, wherein the oxide semiconductor film has a mobility of no less than 5 cm.sup.2/Vs.

A first raw material solution containing at least aluminum is atomized to generate first atomized droplets and a second raw material solution containing at least gallium and a dopant is atomized to generate second atomized droplets, and subsequently, the first atomized droplets are carried into a film forming chamber using a first carrier gas and the second atomized droplets are carried into the film forming chamber using a second carrier gas, and then the first atomized droplets and the second atomized droplets are mixed in the film forming chamber, and the mixed atomized droplets are thermally reacted in the vicinity of a surface of the base to form an oxide semiconductor film on the base, the oxide semiconductor film including, as a major component, a metal oxide containing at least aluminum and gallium, wherein the oxide semiconductor film has a mobility of no less than 5 cm.sup.2/Vs.

A first raw material solution containing at least aluminum is atomized to generate first atomized droplets and a second raw material solution containing at least gallium and a dopant is atomized to generate second atomized droplets, and subsequently, the first atomized droplets are carried into a film forming chamber using a first carrier gas and the second atomized droplets are carried into the film forming chamber using a second carrier gas, and then the first atomized droplets and the second atomized droplets are mixed in the film forming chamber, and the mixed atomized droplets are thermally reacted in the vicinity of a surface of the base to form an oxide film on the base, the oxide film including, as a major component, a metal oxide containing at least aluminum and gallium, the oxide film having a corundum structure, wherein a principal surface of the oxide film is an m-plane.