Abstract: A Ga2O3-based semiconductor device includes a Ga2O3-based crystal layer including a donor, and an N-doped region formed in at least a part of the Ga2O3-based crystal layer.

Abstract: A semiconductor substrate includes a single crystal Ga2O3-based substrate and a polycrystalline substrate that are bonded to each other. A thickness of the single crystal Ga2O3-based substrate is smaller than a thickness of the polycrystalline substrate, and a fracture toughness value of the polycrystalline substrate is higher than a fracture toughness value of the single crystal Ga2O3-based substrate.

Abstract: A trench MOS Schottky diode includes a first semiconductor layer including a Ga2O3-based single crystal, a second semiconductor layer that is a layer laminated on the first semiconductor layer and that includes a Ga2O3-based single crystal and a trench opened on a surface thereof opposite to the first semiconductor layer, an anode electrode formed on the surface of the second semiconductor layer, a cathode electrode formed on a surface of the first semiconductor layer, an insulating film covering an inner surface of the trench, and a trench MOS gate that is buried in the trench so as to be covered with the insulating film and is in contact with the anode electrode. The second semiconductor layer includes a lower layer on a side of the first semiconductor layer and an upper layer on a side of the anode electrode having a higher donor concentration than the lower layer.

Abstract: A semiconductor element includes a high-resistivity substrate that includes a ?-Ga2O3-based single crystal including an acceptor impurity, a buffer layer on the high-resistivity substrate, the buffer layer including a ?-Ga2O3-based single crystal, and a channel layer on the buffer layer, the channel layer including a ?-Ga2O3-based single crystal including a donor impurity. A crystalline laminate structure includes a high-resistivity substrate that includes a ?-Ga2O3-based single crystal including an acceptor impurity, a buffer layer on the high-resistivity substrate, the buffer layer including a ?-Ga2O3-based single crystal, and a donor impurity-containing layer on the buffer layer, the donor impurity-containing layer including a ?-Ga2O3-based single crystal including a donor impurity.

Abstract: A trench MOS-type Schottky diode includes a first semiconductor layer including a Ga2O3-based single crystal, a second semiconductor layer that is a layer laminated on the first semiconductor layer and that includes a Ga2O3-based single crystal and a trench opened on a surface thereof opposite to the first semiconductor layer, an anode electrode formed on the surface of the second semiconductor layer opposite to the first semiconductor layer, a cathode electrode formed on a surface of the first semiconductor layer opposite to the second semiconductor layer, an insulating film covering the inner surface of the trench of the second semiconductor layer, and a trench MOS gate that is embedded in the trench of the second semiconductor layer so as to be covered with the insulating film and is in contact with the anode electrode.

Abstract: A semiconductor substrate includes a single crystal Ga2O3-based substrate and a polycrystalline substrate that are bonded to each other. A thickness of the single crystal Ga2O3-based substrate is smaller than a thickness of the polycrystalline substrate, and a fracture toughness value of the polycrystalline substrate is higher than a fracture toughness value of the single crystal Ga2O3-based substrate.

Abstract: A Ga2O3-based semiconductor device includes a Ga2O3-based crystal layer including a donor, and an N-doped region formed in at least a part of the Ga2O3-based crystal layer.

Abstract: A trench MOS Schottky diode includes a first semiconductor layer including a Ga2O3-based single crystal, a second semiconductor layer that is a layer laminated on the first semiconductor layer and that includes a Ga2O3-based single crystal and a trench opened on a surface thereof opposite to the first semiconductor layer, an anode electrode formed on the surface of the second semiconductor layer, a cathode electrode formed on a surface of the first semiconductor layer, an insulating film covering an inner surface of the trench, and a trench MOS gate that is buried in the trench so as to be covered with the insulating film and is in contact with the anode electrode. The second semiconductor layer includes a lower layer on a side of the first semiconductor layer and an upper layer on a side of the anode electrode having a higher donor concentration than the lower layer.

Abstract: A trench MOS-type Schottky diode includes a first semiconductor layer including a Ga2O3-based single crystal, a second semiconductor layer that is a layer laminated on the first semiconductor layer and that includes a Ga2O3-based single crystal and a trench opened on a surface thereof opposite to the first semiconductor layer, an anode electrode formed on the surface of the second semiconductor layer opposite to the first semiconductor layer, a cathode electrode formed on a surface of the first semiconductor layer opposite to the second semiconductor layer, an insulating film covering the inner surface of the trench of the second semiconductor layer, and a trench MOS gate that is embedded in the trench of the second semiconductor layer so as to be covered with the insulating film and is in contact with the anode electrode.

Abstract: A Ga2O3-based semiconductor element includes an undoped ?-Ga2O3 single crystal film disposed on a surface of a ?-Ga2O3 substrate, a source electrode and a drain electrode disposed on a same side of the undoped ?-Ga2O3 single crystal film, a gate electrode disposed on the undoped ?-Ga2O3 single crystal film between the source electrode and the drain electrode, and a region formed in the undoped ?-Ga2O3 single crystal film under the source electrode and the drain electrode and including a controlled dopant concentration.

Abstract: A semiconductor element includes a base substrate that includes a Ga2O3-based crystal having a thickness of not less than 0.05 ?m and not more than 50 ?m, and an epitaxial layer that includes a Ga2O3-based crystal and is epitaxially grown on the base substrate. A semiconductor element includes an epitaxial layer that includes a Ga2O3-based crystal including an n-type dopant, an ion implanted layer that is formed on a surface of the epitaxial layer and includes a higher concentration of n-type dopant than the epitaxial layer, an anode electrode connected to the epitaxial layer, and a cathode electrode connected to the ion implanted layer.

Abstract: A high withstand voltage Schottky barrier diode includes a first layer that includes a first Ga2O3-based single crystal including a first Group IV element and Cl at a concentration of not more than 5×1016 cm?3 and that has an effective donor concentration of not less than 1×1013 and not more than 6.0×1017 cm?3, a second layer that includes a second Ga2O3-based single crystal including a second Group IV element and that has a higher effective donor concentration than the first layer and is laminated on the first layer, an anode electrode formed on the first layer, and a cathode electrode formed on the second layer.

Abstract: A semiconductor element includes a Molecular Beam Epitaxy (MBE)-grown channel layer including a ?-Ga2O3 single crystal layer. The MBE-grown channel layer is formed on a ?-Ga2O3 single crystal substrate.

Abstract: A high withstand voltage Schottky barrier diode includes a first layer that includes a first Ga2O3-based single crystal including a first Group IV element and Cl at a concentration of not more than 5×1016 cm?3 and that has an effective donor concentration of not less than 1×1013 and not more than 6.0×1017 cm?3, a second layer that includes a second Ga2O3-based single crystal including a second Group IV element and that has a higher effective donor concentration than the first layer and is laminated on the first layer, an anode electrode formed on the first layer, and a cathode electrode formed on the second layer.

Abstract: A semiconductor element includes a high-resistivity substrate that includes a ?-Ga2O3-based single crystal including an acceptor impurity, an undoped ?-Ga2O3-based single crystal layer formed on the high-resistivity substrate, and an n-type channel layer that includes a side surface surrounded by the undoped ?-Ga2O3-based single crystal layer. The undoped ?-Ga2O3-based single crystal layer includes an element isolation region.

Abstract: A semiconductor element includes a high-resistivity substrate that includes a ?-Ga2O3-based single crystal including an acceptor impurity, a buffer layer on the high-resistivity substrate, the buffer layer including a ?-Ga2O3-based single crystal, and a channel layer on the buffer layer, the channel layer including a ?-Ga2O3-based single crystal including a donor impurity. A crystalline laminate structure includes a high-resistivity substrate that includes a ?-Ga2O3-based single crystal including an acceptor impurity, a buffer layer on the high-resistivity substrate, the buffer layer including a ?-Ga2O3-based single crystal, and a donor impurity-containing layer on the buffer layer, the donor impurity-containing layer including a ?-Ga2O3-based single crystal including a donor impurity.

Abstract: A semiconductor element includes a base substrate that includes a Ga2O3-based crystal having a thickness of not less than 0.05 ?m and not more than 50 ?m, and an epitaxial layer that includes a Ga2O3-based crystal and is epitaxially grown on the base substrate. A semiconductor element includes an epitaxial layer that includes a Ga2O3-based crystal including an n-type dopant, an ion implanted layer that is formed on a surface of the epitaxial layer and includes a higher concentration of n-type dopant than the epitaxial layer, an anode electrode connected to the epitaxial layer, and a cathode electrode connected to the ion implanted layer.

Abstract: Provided is a method for controlling a donor concentration in a Ga2O3-based single crystal body. In addition, an ohmic contact having a low resistance is formed between a Ga2O3-based single crystal body and an electrode. A donor concentration in a Ga2O3-based single crystal body is controlled by a method which includes a step wherein Si, which serves as a donor impurity, is introduced into the Ga2O3-based single crystal body by an ion implantation method at an implantation concentration of 1×1020 cm?3 or less, so that a donor impurity implanted region is formed in the Ga2O3-based single crystal body, the donor impurity implanted region having a higher donor impurity concentration than the regions into which Si is not implanted, and a step wherein Si in the donor impurity implanted region is activated by annealing, so that a high donor concentration region is formed.

Abstract: A Ga2O3-based semiconductor element includes a ?-Ga2O3 substrate including a first conductivity type, a first ?-Ga2O3 single crystal film formed on the ?-Ga2O3 substrate, a second ?-Ga2O3 single crystal film including a second conductivity type formed on the first ?-Ga2O3 single crystal film, a source electrode formed on the second ?-Ga2O3 single crystal film, a drain electrode formed on a surface of the ?-Ga2O3 substrate opposite to the first ?-Ga2O3 single crystal film, and a gate electrode formed via a gate insulating film in a trench formed in the second ?-Ga2O3 single crystal film.

Abstract: A Ga2O3-based semiconductor element includes an undoped ?-Ga2O3 single crystal film disposed on a surface of a ?-Ga2O3 substrate, a source electrode and a drain electrode disposed on a same side of the undoped ?-Ga2O3 single crystal film, a gate electrode disposed on the undoped ?-Ga2O3 single crystal film between the source electrode and the drain electrode, and a region formed in the undoped ?-Ga2O3 single crystal film under the source electrode and the drain electrode and including a controlled dopant concentration.