Abstract: A variable speed device that drives an electric motor includes a first acquiring unit that acquires a first parameter concerning an operation state of the electric motor, a second acquiring unit that acquires a second parameter concerning the operation state of the electric motor, the second parameter being related to the first parameter, a third acquiring unit that acquires a third parameter concerning a setting state of the electric motor, and a display control unit that simultaneously displays, on one display screen, a first display item corresponding to the acquired first parameter, a second display item corresponding to the acquired second parameter, and a third display item corresponding to the acquired third parameter. The display control unit graphically displays the first display item and the second display item in association with each other.

Abstract: Group III nitride crystal produced by cutting, from III nitride bulk crystal, a plurality of Group III nitride crystal substrates with major-surface plane orientation misoriented five degrees or less with respect to a crystal-geometrically equivalent plane orientation selected from the group consisting of {20-21}, {20-2-1}, {22-41}, and {22-4-1}, transversely arranging the substrates adjacent to each other such that their major surfaces are parallel to each other and such that their [0001] directions coincide with each other, and growing a Group III nitride crystal on the major surfaces. The Group III nitride crystal substrates are further characterized by satisfying at least either an oxygen-atom concentration of 1×1016 cm?3 to 4×1019 cm?3 or a silicon-atom concentration of 6×1014 cm?3 to 5×1018 cm?3, and by having a carrier concentration of 1×1016 cm?3 to 6×1019 cm?3.

Abstract: A method for producing a Group III nitride crystal includes the steps of cutting a plurality of Group III nitride crystal substrates 10p and 10q having a major surface from a Group III nitride bulk crystal 1, the major surfaces 10pm and 10qm having a plane orientation with an off-angle of five degrees or less with respect to a crystal-geometrically equivalent plane orientation selected from the group consisting of {20?21}, {20?2?1}, {22?41}, and {22?4?1}, transversely arranging the substrates 10p and 10q adjacent to each other such that the major surfaces 10pm and 10qm of the substrates 10p and 10q are parallel to each other and each [0001] direction of the substrates 10p and 10q coincides with each other, and growing a Group III nitride crystal 20 on the major surfaces 10pm and 10qm of the substrates 10p and 10q.

Abstract: A GaN single crystal substrate has a main surface with an area of not less than 10 cm2, the main surface has a plane orientation inclined by not less than 65° and not more than 85° with respect to one of a (0001) plane and a (000-1) plane, and the substrate has at least one of a substantially uniform distribution of a carrier concentration in the main surface, a substantially uniform distribution of a dislocation density in the main surface, and a photoelasticity distortion value of not more than 5×10?5, the photoelasticity distortion value being measured by photoelasticity at an arbitrary point in the main surface when light is applied perpendicularly to the main surface at an ambient temperature of 25° C. Thus, the GaN single crystal substrate suitable for manufacture of a GaN-based semiconductor device having a small variation of characteristics can be obtained.

Abstract: A GaN single crystal substrate has a main surface with an area of not less than 10 cm2, the main surface has a plane orientation inclined by not less than 65° and not more than 85° with respect to one of a (0001) plane and a (000-1) plane, and the substrate has at least one of a substantially uniform distribution of a carrier concentration in the main surface, a substantially uniform distribution of a dislocation density in the main surface, and a photoelasticity distortion value of not more than 5×10?5, the photoelasticity distortion value being measured by photoelasticity at an arbitrary point in the main surface when light is applied perpendicularly to the main surface at an ambient temperature of 25° C. Thus, the GaN single crystal substrate suitable for manufacture of a GaN-based semiconductor device having a small variation of characteristics can be obtained.

Abstract: A method for producing a Group III nitride crystal includes the steps of cutting a plurality of Group III nitride crystal substrates 10p and 10q having a major surface from a Group III nitride bulk crystal 1, the major surfaces 10pm and 10qm having a plane orientation with an off-angle of five degrees or less with respect to a crystal-geometrically equivalent plane orientation selected from the group consisting of {20?21}, {20?2?1}, {22?41}, and {22?4?1}, transversely arranging the substrates 10p and 10q adjacent to each other such that the major surfaces 10pm and 10qm of the substrates 10p and 10q are parallel to each other and each [0001] direction of the substrates 10p and 10q coincides with each other, and growing a Group III nitride crystal 20 on the major surfaces 10pm and 10qm of the substrates 10p and 10q.

Abstract: A GaN single crystal substrate has a main surface with an area of not less than 10 cm2, the main surface has a plane orientation inclined by not less than 65° and not more than 85° with respect to one of a (0001) plane and a (000-1) plane, and the substrate has at least one of a substantially uniform distribution of a carrier concentration in the main surface, a substantially uniform distribution of a dislocation density in the main surface, and a photoelasticity distortion value of not more than 5×10?5, the photoelasticity distortion value being measured by photoelasticity at an arbitrary point in the main surface when light is applied perpendicularly to the main surface at an ambient temperature of 25° C. Thus, the GaN single crystal substrate suitable for manufacture of a GaN-based semiconductor device having a small variation of characteristics can be obtained.

Abstract: A method for producing a group III nitride crystal in the present invention includes the steps of cutting a plurality of group III nitride crystal substrates 10p and 10q having a main plane from a group III nitride bulk crystal 1, the main planes 10pm and 10qm having a plane orientation with an off-angle of five degrees or less with respect to a crystal-geometrically equivalent plane orientation selected from the group consisting of {20-21}, {20-2-1}, {22-41}, and {22-4-1}, transversely arranging the substrates 10p and 10q adjacent to each other such that the main planes 10pm and 10qm of the substrates 10p and 10q are parallel to each other and each [0001] direction of the substrates 10p and 10q coincides with each other, and growing a group III nitride crystal 20 on the main planes 10pm and 10qm of the substrates 10p and 10q.

Abstract: A nitride semiconductor device includes a main surface and an indicator portion. The main surface is a plane inclined by at least 71° and at most 79° in a [1-100] direction from a (0001) plane or a plane inclined by at least 71° and at most 79° in a [?1100] direction from a (000-1) plane. The indicator portion indicates a (?1017) plane, a (10-1-7) plane, or a plane inclined by at least ?4° and at most 4° in the [1-100] direction from these planes and inclined by at least ?0.5° and at most 0.5° in a direction orthogonal to the [1-100] direction.

Abstract: A nitride semiconductor device includes a main surface and an indicator portion. The main surface is a plane inclined by at least 71° and at most 79° in a [1-100] direction from a (0001) plane or a plane inclined by at least 71° and at most 79° in a [?1100] direction from a (000-1) plane. The indicator portion indicates a (?1017) plane, a (10-1-7) plane, or a plane inclined by at least ?4° and at most 4° in the [1-100] direction from these planes and inclined by at least ?0.5° and at most 0.5° in a direction orthogonal to the [1-100] direction.

Abstract: A method for producing a group III nitride crystal in the present invention includes the steps of cutting a plurality of group III nitride crystal substrates 10p and 10q having a main plane from a group III nitride bulk crystal 1, the main planes 10pm and 10qm having a plane orientation with an off-angle of five degrees or less with respect to a crystal-geometrically equivalent plane orientation selected from the group consisting of {20-21}, {20-2-1}, {22-41}, and {22-4-1}, transversely arranging the substrates 10p and 10q adjacent to each other such that the main planes 10pm and 10qm of the substrates 10p and 10q are parallel to each other and each [0001] direction of the substrates 10p and 10q coincides with each other, and growing a group III nitride crystal 20 on the main planes 10pm and 10qm of the substrates 10p and 10q.

Abstract: A gallium nitride-based semiconductor optical device is provided that includes an indium-containing gallium nitride-based semiconductor layer that exhibit low piezoelectric effect and high crystal quality. The gallium nitride-based semiconductor optical device 11a includes a GaN support base 13, a GaN-based semiconductor region 15, and well layers 19. A primary surface 13a tilts from a surface orthogonal to a reference axis that extends in a direction from one crystal axis of the m-axis and the a-axis of GaN toward the other crystal axis. The tilt angle AOFF is 0.05 degree or more to less than 15 degrees. The angle AOFF is equal to the angle defined by a vector VM and a vector VN. The inclination of the primary surface is shown by a typical m-plane SM and m-axis vector VM. The GaN-based semiconductor region 15 is provided on the primary surface 13a. In the well layers 19 in an active layer 17, both the m-plane and the a-plane of the well layers 19 tilt from a normal axis AN of the primary surface 13a.

Abstract: The present invention is to provide GaN crystal growing method for growing a GaN crystal with few stacking faults on a GaN seed crystal substrate having a main surface inclined at an angle of 20° to 90° from the (0001) plane, and also to provide a GaN crystal substrate with few stacking faults. A method for growing a GaN crystal includes the steps of preparing a GaN seed crystal substrate 10 having a main surface 10m inclined at an angle of 20° to 90° from a (0001) plane 10c and growing a GaN crystal 20 on the GaN seed crystal substrate 10. The GaN seed crystal substrate 10 and the GaN crystal 20 have a difference in impurity concentration of 3×1018 cm?3 or less.

Abstract: The present invention provides a method of manufacturing a nitride semiconductor substrate capable of efficiently manufacturing a nitride semiconductor substrate having a nonpolar plane as a major surface in which polycrystalline growth is minimized. A method of manufacturing a GaN substrate, which is a nitride semiconductor substrate, includes steps (S10 and S20) of preparing a starting substrate composed of GaN and having a major surface with an off-axis angle of between 4.1° and 47.8° inclusive with respect to a {1-100} plane, a step (S40) of epitaxially growing a semiconductor layer made of GaN on the major surface of the starting substrate, and a step (S50) of picking out a GaN substrate having an m plane as the major surface from the semiconductor layer.

Abstract: A GaN single crystal substrate has a main surface with an area of not less than 10 cm2, the main surface has a plane orientation inclined by not less than 65° and not more than 85° with respect to one of a (0001) plane and a (000-1) plane, and the substrate has at least one of a substantially uniform distribution of a carrier concentration in the main surface, a substantially uniform distribution of a dislocation density in the main surface, and a photoelasticity distortion value of not more than 5×10?5, the photoelasticity distortion value being measured by photoelasticity at an arbitrary point in the main surface when light is applied perpendicularly to the main surface at an ambient temperature of 25° C. Thus, the GaN single crystal substrate suitable for manufacture of a GaN-based semiconductor device having a small variation of characteristics can be obtained.

Abstract: A GaN substrate having a large diameter of two inches or more by which a semiconductor device such as a light emitting element with improved characteristics such as luminance efficiency, an operating life and the like can be obtained at low cost industrially, a substrate having an epitaxial layer formed on the GaN substrate, a semiconductor device, and a method of manufacturing the GaN substrate are provided. A GaN substrate has a main surface and contains a low-defect crystal region and a defect concentrated region adjacent to low-defect crystal region. Low-defect crystal region and defect concentrated region extend from the main surface to a back surface positioned on the opposite side of the main surface. A plane direction [0001] is inclined in an off-angle direction with respect to a normal vector of the main surface.

Abstract: A gallium nitride-based semiconductor optical device is provided that includes an indium-containing gallium nitride-based semiconductor layer that exhibit low piezoelectric effect and high crystal quality. The gallium nitride-based semiconductor optical device 11a includes a GaN support base 13, a GaN-based semiconductor region 15, and well layers 19. A primary surface 13a tilts from a surface orthogonal to a reference axis that extends in a direction from one crystal axis of the m-axis and the a-axis of GaN toward the other crystal axis. The tilt angle AOFF is equal to the angle defined by a vector VM and a vector VN. The inclination of the primary surface is shown by a typical m-plane SM and m-axis vector VM. The GaN-based semiconductor region 15 is provided on the primary surface 13a. In the well layers 19 in an active layer 17, both the m-plane and the a-plane of the well layers 19 tilt from a normal axis AN of the primary surface 13a. The indium content of the well layers 19 is 0.1 or more.

Abstract: A GaN substrate having a large diameter of two inches or more by which a semiconductor device such as a light emitting element with improved characteristics such as luminance efficiency, an operating life and the like can be obtained at low cost industrially, a substrate having an epitaxial layer formed on the GaN substrate, a semiconductor device, and a method of manufacturing the GaN substrate are provided. A GaN substrate has a main surface and contains a low-defect crystal region and a defect concentrated region adjacent to low-defect crystal region. Low-defect crystal region and defect concentrated region extend from the main surface to a back surface positioned on the opposite side of the main surface. A plane direction [0001] is inclined in an off-angle direction with respect to a normal vector of the main surface.

Abstract: The turbocharged engine in accordance with the present invention comprises an EGR unit having an EGR passage linking an intake passage and an exhaust passage and an EGR valve provided in the EGR passage. The engine further comprises deceleration deciding unit for deciding as to whether a vehicle decelerates, and intake air release unit for opening the EGR valve and causing part of the intake air present in the intake passage to flow into the exhaust passage through the EGR passage when the deceleration deciding unit decides that the vehicle is decelerating.

Abstract: The turbocharged engine in accordance with the present invention comprises an EGR unit having an EGR passage linking an intake passage and an exhaust passage and an EGR valve provided in the EGR passage. The engine further comprises deceleration deciding unit for deciding as to whether a vehicle decelerates, and intake air release unit for opening the EGR valve and causing part of the intake air present in the intake passage to flow into the exhaust passage through the EGR passage when the deceleration deciding unit decides that the vehicle is decelerating.