Abstract: A vertical tail of a helicopter has a leading edge and a trailing edge concave toward the leading edge. The helicopter includes a main rotor and a tail rotor for generating anti-torque to cancel torque generated by rotation of the main rotor. The trailing edge is concave within a range within which the vertical tail overlaps a circular region, formed as a rotation range of the tail rotor, in a rotation axis direction of the tail rotor.

Abstract: A DPTSS fiber optic cable includes an optical fiber sheathing cylindrical metal tube accommodating a pressure sensor optical fiber and having a plurality of through holes formed therein; and pressure blocking sections formed at intervals in the axial direction of the cable.

Abstract: A DPTSS fiber optic cable includes an optical fiber sheathing cylindrical metal tube accommodating a pressure sensor optical fiber and having a plurality of through holes formed therein; and pressure blocking sections formed at intervals in the axial direction of the cable.

Abstract: A vertical semiconductor device in which pinch-off characteristics and breakdown voltage characteristics can be stably improved by fixing the electric potential of a p-type GaN barrier layer with certainty is provided. The semiconductor device includes a GaN-based stacked layer having an opening, a regrown layer including a channel located so as to cover a wall surface of the opening, an n+-type source layer that is in ohmic contact with the source electrode, a p-type GaN barrier layer, and a p+-type GaN-based supplementary layer located between the p-type GaN barrier layer and the n+-type source layer. The p+-type GaN-based supplementary layer and the n+-type source layer form a tunnel junction to fix the electric potential of the p-type GaN barrier layer at a source potential.

Abstract: It is an object to improve the breakdown voltage characteristics of a vertical semiconductor device having an opening and including a channel formed of two-dimensional electron gas in the opening. A GaN-based stacked layer 15 includes n?-type GaN drift layer 4/p-type GaN barrier layer 6/n+-type GaN contact layer 7. An opening 28 extends from a top layer and reaches the n?-type GaN drift layer 4. The semiconductor device includes a regrown layer 27 located so as to cover a wall surface and a bottom portion of the opening, the regrown layer 27 including an electron drift layer 22 and an electron source layer 26, a source electrode S located around the opening, a gate electrode G located on the regrown layer in the opening, and a bottom insulating layer 37 located in the bottom portion of the opening.

Abstract: It is an object to improve the breakdown voltage characteristics of a vertical semiconductor device having an opening and including a channel formed of two-dimensional electron gas in the opening. The vertical semiconductor device includes a GaN-based stacked layer 15 having an opening 28 and the GaN-based stacked layer 15 includes n-type GaN-based drift layer 4/p-type GaN-based barrier layer 6/n-type GaN-based contact layer 7. The vertical semiconductor device includes a regrown layer 27 located so as to cover the opening, the regrown layer 27 including an electron drift layer 22 and an electron supply layer 26, a source electrode S, and a gate electrode G located on the regrown layer. The gate electrode G covers a portion having a length corresponding to the thickness of the p-type GaN-based barrier layer and is terminated at a position on the wall surface, the position being away from the bottom portion of the opening.

Abstract: In a vertical semiconductor device including a channel in an opening, a semiconductor device whose high-frequency characteristics can be improved and a method for producing the semiconductor device are provided. The semiconductor device includes n-type GaN-based drift layer 4/p-type GaN-based barrier layer 6/n-type GaN-based contact layer 7. An opening 28 extends from a top layer and reaches the n-type GaN-based drift layer. The semiconductor device includes a regrown layer 27 located so as to cover the opening, the regrown layer 27 including an electron drift layer 22 and an electron supply layer 26, a source electrode S, a drain electrode D, and a gate electrode G located on the regrown layer. Assuming that the source electrode serving as one electrode and the drain electrode serving as the other electrode constitute a capacitor, the semiconductor device includes a capacitance-decreasing structure that decreases the capacitance of the capacitor.

Abstract: There is provided a vertical GaN-based semiconductor device in which the on-resistance can be decreased while the breakdown voltage characteristics are improved using a p-type GaN barrier layer. The semiconductor device includes a regrown layer 27 including a channel located on a wall surface of an opening 28, a p-type barrier layer 6 whose end face is covered, a source layer 7 that is in contact with the p-type barrier layer, a gate electrode G located on the regrown layer, and a source electrode S located around the opening. In the semiconductor device, the source layer has a superlattice structure that is constituted by a stacked layer including a first layer (a layer) having a lattice constant smaller than that of the p-type barrier layer and a second layer (b layer) having a lattice constant larger than that of the first layer.

Abstract: In a vertical semiconductor device including a channel in an opening, a semiconductor device whose high-frequency characteristics can be improved and a method for producing the semiconductor device are provided. The semiconductor device includes n-type GaN-based drift layer 4/p-type GaN-based barrier layer 6/n-type GaN-based contact layer 7. An opening 28 extends from a top layer and reaches the n-type GaN-based drift layer. The semiconductor device includes a regrown layer 27 located so as to cover the opening, the regrown layer 27 including an electron drift layer 22 and an electron supply layer 26, a source electrode S, a drain electrode D, and a gate electrode G located on the regrown layer. Assuming that the source electrode serving as one electrode and the drain electrode serving as the other electrode constitute a capacitor, the semiconductor device includes a capacitance-decreasing structure that decreases the capacitance of the capacitor.

Abstract: There is provided a semiconductor device or the like which includes a channel and a gate electrode in an opening and in which electric field concentration near a bottom portion of the opening can be reduced. The semiconductor device includes n?-type GaN drift layer 4/p-type GaN barrier layer 6/n+-type GaN contact layer. An opening 28 extends from the top layer and reaches the n-type GaN-based drift layer. The semiconductor device includes a regrown layer 27 located in the opening, the regrown layer 27 including an electron supply layer 26 and an electron drift layer 22, a source electrode S, a drain electrode D, a gate electrode G located on the regrown layer, and a semiconductor impurity adjustment region 31 disposed in the bottom portion of the opening. The impurity adjustment region 31 is a region that promotes a potential drop from the drain electrode side to the gate electrode side in a potential distribution in an off-state.

Abstract: It is an object to improve the breakdown voltage characteristics of a vertical semiconductor device having an opening and including a channel formed of two-dimensional electron gas in the opening. A GaN-based stacked layer 15 includes n?-type GaN drift layer 4/p-type GaN barrier layer 6/n+-type GaN contact layer 7. An opening 28 extends from a top layer and reaches the n?-type GaN drift layer 4. The semiconductor device includes a regrown layer 27 located so as to cover a wall surface and a bottom portion of the opening, the regrown layer 27 including an electron drift layer 22 and an electron source layer 26, a source electrode S located around the opening, a gate electrode G located on the regrown layer in the opening, and a bottom insulating layer 37 located in the bottom portion of the opening.

Abstract: It is an object to improve the breakdown voltage characteristics of a vertical semiconductor device having an opening and including a channel formed of two-dimensional electron gas in the opening. The vertical semiconductor device includes a GaN-based stacked layer 15 having an opening 28 and the GaN-based stacked layer 15 includes n-type GaN-based drift layer 4/p-type GaN-based barrier layer 6/n-type GaN-based contact layer 7. The vertical semiconductor device includes a regrown layer 27 located so as to cover the opening, the regrown layer 27 including an electron drift layer 22 and an electron supply layer 26, a source electrode S, and a gate electrode G located on the regrown layer. The gate electrode G covers a portion having a length corresponding to the thickness of the p-type GaN-based barrier layer and is terminated at a position on the wall surface, the position being away from the bottom portion of the opening.

Abstract: There is provided a vertical GaN-based semiconductor device in which the on-resistance can be decreased while the breakdown voltage characteristics are improved using a p-type GaN barrier layer. The semiconductor device includes a regrown layer 27 including a channel located on a wall surface of an opening 28, a p-type barrier layer 6 whose end face is covered, a source layer 7 that is in contact with the p-type barrier layer, a gate electrode G located on the regrown layer, and a source electrode S located around the opening. In the semiconductor device, the source layer has a superlattice structure that is constituted by a stacked layer including a first layer (a layer) having a lattice constant smaller than that of the p-type barrier layer and a second layer (b layer) having a lattice constant larger than that of the first layer.

Abstract: A vertical semiconductor device in which pinch-off characteristics and breakdown voltage characteristics can be stably improved by fixing the electric potential of a p-type GaN barrier layer with certainty is provided. The semiconductor device includes a GaN-based stacked layer having an opening, a regrown layer including a channel located so as to cover a wall surface of the opening, an n+-type source layer that is in ohmic contact with the source electrode, a p-type GaN barrier layer, and a p+-type GaN-based supplementary layer located between the p-type GaN barrier layer and the n+-type source layer. The p+-type GaN-based supplementary layer and the n+-type source layer form a tunnel junction to fix the electric potential of the p-type GaN barrier layer at a source potential.

Abstract: A semiconductor device includes: a semiconductor layer made of Fe-doped GaN; a first buffer layer that is provided on the semiconductor layer so as to contact an upper surface of the semiconductor layer and is made of AlN or AlxGa1-xN (0.4<x<1); and an operating layer that is provided on the first buffer layer and is made of a GaN-based semiconductor.

Abstract: A method for fabricating a semiconductor device includes growing an AlN layer by MOVPE in which a nitrogen-source flow ratio at a far side from a substrate is set lower than that at a near side, the nitrogen-source flow ratio being a ratio of a flow rate of a nitrogen source to a total flow rate of growth gas; and growing a GaN-based semiconductor layer on the AlN layer by MOVPE.

Abstract: A semiconductor device includes: a semiconductor layer made of Fe-doped GaN; a first buffer layer that is provided on the semiconductor layer so as to contact an upper surface of the semiconductor layer and is made of AlN or AlxGa1-xN (0.4<x<1); and an operating layer that is provided on the first buffer layer and is made of a GaN-based semiconductor.

Abstract: A method for fabricating a semiconductor device includes growing an AlN layer by MOVPE in which a nitrogen-source flow ratio at a far side from a substrate is set lower than that at a near side, the nitrogen-source flow ratio being a ratio of a flow rate of a nitrogen source to a total flow rate of growth gas; and growing a GaN-based semiconductor layer on the AlN layer by MOVPE.

Abstract: A semiconductor device includes a substrate, a buffer layer that is formed with an aluminum nitride layer on the substrate and has a film thickness of 5 nm to 40 nm, an operating layer that is formed with a gallium nitride-based semiconductor on the buffer layer, and a control electrode that is formed on the operating layer.

Abstract: A semiconductor device includes a substrate, a buffer layer that is formed with an aluminum nitride layer on the substrate and has a film thickness of 5 nm to 40 nm, an operating layer that is formed with a gallium nitride-based semiconductor on the buffer layer, and a control electrode that is formed on the operating layer.