Abstract:
A semiconductor device includes a semiconductor layer stack formed on a substrate, a first ohmic electrode and a second ohmic electrode which are formed on the semiconductor layer stack, and are spaced from each other, a first control layer formed between the first ohmic electrode and the second ohmic electrode, and a first gate electrode formed on the first control layer. The first control layer includes a lower layer, an intermediate layer which is formed on the lower layer, and has lower impurity concentration than the lower layer, and an upper layer which is formed on the intermediate layer, and has higher impurity concentration than the intermediate layer.
Abstract:
A motor driving circuit includes a three-phase inverter circuit 8, including three upper-arm switching elements 56a to 56c for driving upper arms of different phases of a three-phase motor 3, and three lower-arm switching elements 56d to 56f for driving lower arms of different phases. At least one of the upper-arm switching elements 56a to 56c and the lower-arm switching elements 56d to 56f is a semiconductor element that performs a diode operation. The diode operation is an operation in which a voltage less than or equal to a threshold voltage of a gate electrode G is applied to the gate electrode G with reference to a potential of a first ohmic electrode S, thereby conducting a current flow from the first ohmic electrode S to a second ohmic electrode D and blocking a current flow from the second ohmic electrode D to the first ohmic electrode S.
Abstract:
A semiconductor device includes a semiconductor layer stack 13 formed on a substrate 11 and having a channel region, a first electrode 16A and a second electrode 16B formed spaced apart from each other on the semiconductor layer stack 13, a first gate electrode 18A formed between the first electrode 16A and the second electrode 16B, and a second gate electrode 18B formed between the first gate electrode 18A and the second electrode 16B. A first control layer 19A having a p-type conductivity is formed between the semiconductor layer stack 13 and the first gate electrode 18A.
Abstract:
A semiconductor device includes a semiconductor layer stack formed on a substrate, a first ohmic electrode and a second ohmic electrode which are formed on the semiconductor layer stack, and are spaced from each other, a first control layer formed between the first ohmic electrode and the second ohmic electrode, and a first gate electrode formed on the first control layer. The first control layer includes a lower layer, an intermediate layer which is formed on the lower layer, and has lower impurity concentration than the lower layer, and an upper layer which is formed on the intermediate layer, and has higher impurity concentration than the intermediate layer.
Abstract:
A material of a gate electrode is a conductive oxide having a higher work function than that of conventionally used Pd and so on, thereby achieving a normally-off transistor without reducing the sheet carrier concentration of a heterojunction. It is thus possible to achieve a normally-off operation while reducing an increase in the specific on-state resistance.
Abstract:
A bidirectional switch includes a plurality of unit cells 11 including a first ohmic electrode 15, a first gate electrode 17, a second gate electrode 18, and a second ohmic electrode 16. The first gate electrodes 15 are electrically connected via a first interconnection 31 to a first gate electrode pad 43. The second gate electrodes 18 are electrically connected via a second interconnection 32 to a second gate electrode pad 44. A unit cell 11 including a first gate electrode 17 having the shortest interconnect distance from the first gate electrode pad 43 includes a second gate electrode 18 having the shortest interconnect distance from the second gate electrode pad 44.
Abstract:
A semiconductor device includes: a semiconductor substrate; a diode having a cathode formed on a first surface side of the semiconductor substrate and an anode formed on a second surface side of the semiconductor substrate; and a transistor formed over the semiconductor substrate. The transistor includes a semiconductor layer laminate formed over the semiconductor substrate, a source electrode and a drain electrode that are formed spaced apart from each other over the semiconductor layer laminate, and a gate electrode formed between the source electrode and the drain electrode. The source electrode is electrically connected to the anode, and the drain electrode is electrically connected to the cathode.
Abstract:
Reduction of noise is achieved by devising an arrangement of heat generating parts such as a light valve element, an electric power source, a light source, etc. and an arrangement of cooling fans. In cooling the light source, the electric power source and liquid crystal panels, a cooling wind path for the liquid crystal panels and the electric power source is made separate from and independent of a cooling wind path for the light source that generates much heat, a cooling air volume is optimized for the respective cooling wind paths, and noise accompanying the rotation of the cooling fans is reduced. Also, by arranging the cooling fans substantially centrally of the respective cooling wind paths, that volume of noise, which leaks from air intake ports and air exhaust port that are opened to a housing of a unit, is reduced.
Abstract:
A nitride semiconductor device includes a semiconductor stacked structure which is formed of a nitride semiconductor having a first principal surface and a second principal surface opposed to the first principal surface and which includes an active layer. The first principal surface of the semiconductor stacked structure is formed with a plurality of indentations whose plane orientations are the {0001} plane, and the plane orientation of the second principal surface is the {1-101} plane. The active layer is formed along the {1-101} plane.
Abstract:
Reduction of noise is achieved by devising an arrangement of heat generating parts such as a light valve element, an electric power source, a light source, etc. and an arrangement of cooling fans. In cooling the light source, the electric power source and liquid crystal panels, a cooling wind path for the liquid crystal panels and the electric power source is made separate from and independent of a cooling wind path for the light source that generates much heat, a cooling air volume is optimized for the respective cooling wind paths, and noise accompanying the rotation of the cooling fans is reduced. Also, by arranging the cooling fans substantially centrally of the respective cooling wind paths, that volume of noise, which leaks from air intake ports and air exhaust port that are opened to a housing of a unit, is reduced.