Abstract: A crucible for growing a single-crystal in which a raw material melt for growing the single-crystal is solidified while being accommodated includes a side wall part configured to surround the raw material melt and a bottom part configured to support the raw material melt while being continuous with the side wall part, in which the side wall part has circumferential length redundancy inside the side wall part in a cross-sectional view. The side wall part has a portion where the circumference length is redundant inside any portion in the cross-sectional view, and when the crucible for growing a single-crystal is cooled in a cooling process after the single-crystal growth, the portion where the circumference length is redundant inside in the cross-sectional view is expanded to an outside of the crucible for growing a single-crystal.

Abstract: To prevent dielectric breakdown of a Schottky barrier diode using gallium oxide. A Schottky barrier diode has a drift layer provided on a semiconductor substrate, an anode electrode, and a cathode electrode. A width W1 of an outer peripheral trench formed in the drift layer is larger than a width W2 of a center trench. An outer peripheral wall S1 of the outer peripheral trench is curved so as to approach vertical toward the outside, while an inner peripheral wall S2 thereof is closer to vertical than the outer peripheral wall S1. This relaxes an electric field which occurs at the outer peripheral bottom portion of the outer peripheral trench upon application of a backward voltage.

Abstract: To prevent dielectric breakdown of a Schottky barrier diode using gallium oxide. A Schottky barrier diode has a drift layer provided on a semiconductor substrate, an anode electrode, and a cathode electrode. A part of the anode electrode is embedded in an outer peripheral trench and a center trench through an insulating film. The insulating film is formed such that the thickness thereof in the depth direction of the outer peripheral trench becomes larger toward the outside, whereby an outer peripheral wall S1 of the anode electrode embedded in the outer peripheral trench is curved so as to approach vertical toward the outside. This results in relaxation of an electric field which occurs at the outer peripheral bottom portion of the outer peripheral trench upon application of a backward voltage.

Abstract: In a crystal manufacturing method, first, a feedstock including a tapered tip portion is disposed above a crystal growth region. Then, a side surface of the tip portion is selectively heated and melted by radiant heat traveling diagonally upward while a shape of the tip portion is maintained, and the side surface of the tip portion is physically connected to an upper surface of the crystal growth region by a material melted from the side surface. In a crystal manufacturing apparatus, the radiant heat for melting the feedstock is radiated from an electric resistance heater.

Abstract: A Schottky barrier diode includes an anode electrode which is brought into Schottky contact with a drift layer, a cathode electrode which is brought into ohmic contact with a semiconductor substrate, an insulating film covering the inner wall of a trench formed in the drift layer, a metal film covering the inner wall of the trench through the insulating film and electrically connected to the anode electrode, and a field insulating layer. The field insulating layer includes a first part positioned between an upper surface of the drift layer and the anode electrode and a second part covering the inner wall of the trench through the metal film and insulating film. With this configuration, even when misalignment occurs between the trench and the field insulating layer, dielectric breakdown can be prevented.

Abstract: A substrate 10 comprises: a first layer L1 containing crystalline aluminum nitride; a second layer L2 containing crystalline ?-alumina; and an intermediate layer Lm sandwiched between the first layer L1 and the second layer L2 and containing aluminum, nitrogen, and oxygen, and the content of nitrogen in the intermediate layer Lm decreases in a direction Z from the first layer L1 toward the second layer L2, and the content of oxygen in the intermediate layer Lm increases in the direction Z from the first layer L1 toward the second layer L2.

Abstract: An object of the present invention is to provide a Schottky barrier diode which is less likely to cause dielectric breakdown due to concentration of an electric field. A Schottky barrier diode includes a semiconductor substrate 20 made of gallium oxide, a drift layer 30 made of gallium oxide and provided on the semiconductor substrate 20, an anode electrode 40 brought into Schottky contact with the drift layer 30, and a cathode electrode 50 brought into ohmic contact with the semiconductor substrate 20. The drift layer 30 has an outer peripheral trench 10 formed at a position surrounding the anode electrode 40 in a plan view. An electric field is dispersed by the presence of the outer peripheral trench 10 formed in the drift layer 30. This alleviates concentration of the electric field on the corner of the anode electrode 40, making it unlikely to cause dielectric breakdown.

Abstract: A Schottky barrier diode includes a semiconductor substrate made of gallium oxide, a drift layer made of gallium oxide and formed on the semiconductor substrate, an anode electrode brought into Schottky contact with the drift layer, a cathode electrode brought into ohmic contact with the semiconductor substrate, an insulating film covering the inner wall of a trench formed in the drift layer, and a protective film covering the anode electrode, wherein a part of the protective film is embedded in the trench. The part of the protective film is thus embedded in the trench, so that adhesion performance between the anode electrode and protective film is enhanced. This makes it possible to prevent peeling at the boundary between the anode electrode and the protective film.

Abstract: A die for EFG-based single crystal growth includes a lower surface to be immersed into a raw material melt with an impurity added, a rectangular upper surface facing a seed crystal and having a long side and a short side, and a plurality of slit sections extending from the lower surface to the upper surface and causing the raw material melt to ascend from the lower surface to the upper surface. Respective longitudinal directions of openings of the plurality of slit sections on the upper surface are parallel to one another and non-parallel to the long side of the upper surface.

Abstract: In a crystal manufacturing method, first, a feedstock including a tapered tip portion is disposed above a crystal growth region. Then, a side surface of the tip portion is selectively heated and melted by radiant heat traveling diagonally upward while a shape of the tip portion is maintained, and the side surface of the tip portion is physically connected to an upper surface of the crystal growth region by a material melted from the side surface. In a crystal manufacturing apparatus, the radiant heat for melting the feedstock is radiated from an electric resistance heater.

Abstract: Provided is a crucible including: a melt reservoir that collects a melt that becomes a raw material of a crystal; and a nozzle portion that controls a shape of the crystal. The nozzle portion includes nozzle holes that allow the melt to flow out from the melt reservoir to an end surface of the nozzle portion. Surface roughness of an inner peripheral surface of the nozzle holes is 10 ?m or less.

Abstract: A crucible for growing a single-crystal in which a raw material melt for growing the single-crystal is solidified while being accommodated includes a side wall part configured to surround the raw material melt and a bottom part configured to support the raw material melt while being continuous with the side wall part, in which the side wall part has circumferential length redundancy inside the side wall part in a cross-sectional view. The side wall part has a portion where the circumference length is redundant inside any portion in the cross-sectional view, and when the crucible for growing a single-crystal is cooled in a cooling process after the single-crystal growth, the portion where the circumference length is redundant inside in the cross-sectional view is expanded to an outside of the crucible for growing a single-crystal.

Abstract: A die for EFG-based single crystal growth includes a lower surface to be immersed into a raw material melt with an impurity added, a rectangular upper surface facing a seed crystal and having a long side and a short side, and a plurality of slit sections extending from the lower surface to the upper surface and causing the raw material melt to ascend from the lower surface to the upper surface. Respective longitudinal directions of openings of the plurality of slit sections on the upper surface are parallel to one another and non-parallel to the long side of the upper surface.

Abstract: An object of the present invention is to provide a Schottky barrier diode which is less likely to cause dielectric breakdown due to concentration of an electric field. A Schottky barrier diode includes a semiconductor substrate 20 made of gallium oxide, a drift layer 30 made of gallium oxide and provided on the semiconductor substrate 20, an anode electrode 40 brought into Schottky contact with the drift layer 30, and a cathode electrode 50 brought into ohmic contact with the semiconductor substrate 20. The drift layer 30 has an outer peripheral trench 10 formed at a position surrounding the anode electrode 40 in a plan view. An electric field is dispersed by the presence of the outer peripheral trench 10 formed in the drift layer 30. This alleviates concentration of the electric field on the corner of the anode electrode 40, making it unlikely to cause dielectric breakdown.

Abstract: A substrate 10 comprises: a first layer L1 containing crystalline aluminum nitride; a second layer L2 containing crystalline ?-alumina; and an intermediate layer Lm sandwiched between the first layer L1 and the second layer L2 and containing aluminum, nitrogen, and oxygen, and the content of nitrogen in the intermediate layer Lm decreases in a direction Z from the first layer L1 toward the second layer L2, and the content of oxygen in the intermediate layer Lm increases in the direction Z from the first layer L1 toward the second layer L2.

Abstract: A nitride single crystal having high crystallinity is provided. A nitride single crystal 10 has a wurtzite crystal structure, and a content of boron is 0.5 ppm by mass or more and 251 ppm by mass or less.

Abstract: An alumina substrate on which an AlN layer is formed and that causes less warping, and a substrate material strong enough to withstand normal handling when an AlN crystal is grown upon it, and prevents cracking and fracturing of a grown crystal when stress is applied during growing or cooling. The substrate has a gap and a rare earth element-containing region inside the AlN layer or at the interface between the AlN layer and the alumina substrate. Warping of the AlN layer can be reduced by lattice-mismatch stress being concentrated at the region and releasing of stress by the gap. The region having a concentrating of stress, and the gap having a low mechanical strength, can induce crackings and fracturings. As a result, contamination of crackings and fracturings into the crystal grown on the substrate can be prevented. The region can ensure a level of mechanical strength sufficient for handling.

Abstract: An alumina substrate having a carbon-containing phase with an AlN layer formed on a surface of the alumina substrate.

Abstract: An alumina substrate wherein an AlN layer is formed on a surface of the alumina substrate and a rare earth elements-containing layer and/or rare earth elements-containing regions is/are formed in the interior of the AlN layer or in the interface between the AlN layer and the alumina substrate.

Abstract: An alumina substrate on which an AlN layer is formed and that causes less warping, and a substrate material strong enough to withstand normal handling when an AlN crystal is grown upon it, and prevents cracking and fracturing of a grown crystal when stress is applied during growing or cooling. The substrate has a gap and a rare earth element-containing region inside the AlN layer or at the interface between the AlN layer and the alumina substrate. Warping of the AlN layer can be reduced by lattice-mismatch stress being concentrated at the region and releasing of stress by the gap. The region having a concentrating of stress, and the gap having a low mechanical strength, can induce crackings and fracturings. As a result, contamination of crackings and fracturings into the crystal grown on the substrate can be prevented. The region can ensure a level of mechanical strength sufficient for handling.