Abstract: An AlGaN/GaN HEMT includes a compound semiconductor laminated structure, a gate electrode formed above the compound semiconductor laminated structure, and a p-type semiconductor layer formed between the compound semiconductor laminated structure and the gate electrode, and the p-type semiconductor layer has tensile strain in a direction parallel to a surface of the compound semiconductor laminated structure.

Abstract: A compound semiconductor device includes a compound semiconductor composite structure in which two-dimensional electron gas is generated; and an electrode that is formed on the compound semiconductor composite structure, wherein the compound semiconductor composite structure includes a p-type semiconductor layer below a portion where the two-dimensional electron gas is generated, and the p-type semiconductor layer includes a portion containing a larger amount of an ionized acceptor than other portions of the p-type semiconductor layer, the portion being located below the electrode.

Abstract: A semiconductor device includes a first semiconductor layer formed on a substrate, the first semiconductor containing an impurity element; a second semiconductor layer formed on the first semiconductor layer; a third semiconductor layer formed on the second semiconductor layer; and a gate electrode, a source electrode and a drain electrode that are formed on the third semiconductor layer. In the semiconductor device, the second semiconductor layer includes an impurity diffusion region in which an impurity element contained in the first semiconductor layer is diffused, the impurity diffusion region being located directly beneath the gate electrode and being in contact with the first semiconductor layer, and the impurity element causes the impurity diffusion region to be a p-type impurity diffusion region.

Abstract: A driver circuit includes an output terminal connected to a gate of a Schottky transistor, a reference transistor formed in the same manner as the Schottky transistor, a resistor connected between a first power source line and a gate of the reference transistor, a voltage generator configured to supply a second node with a voltage equal to or lower than a voltage at a first node between the resistor and the reference transistor, and a switching element configured to transmit the voltage at the second node to the output terminal in response to a signal inputted to an input terminal.

Abstract: An AlGaN/GaN HEMT includes: a compound semiconductor layer; a source electrode and a drain electrode formed on an upper side of the compound semiconductor layer; and an Al—Si—N layer being a high-resistance layer disposed in a lower portion of at least one of the source electrode and the drain electrode and higher in an electric resistance value than the source electrode and the drain electrode.

Abstract: A power supply unit includes first and second sub-power supply module, each having first and second inductor, first and second switching element which switches current supplied from an input power supply to the first and second inductor, first and second drive control circuit which drives the first and second switching element, and first and second sub-output terminal to which current is output from the first and second inductor respectively; and a common output terminal to which the first sub-output terminal and the second sub-output terminal are coupled, wherein an ON operation of the first switching element is controlled depending on whether or not an output voltage of the common output terminal is lower than a first voltage, and an ON operation of the second switching element is controlled depending on whether or not the output voltage is lower than a second voltage, which is different from the first voltage.

Abstract: A first transistor coupled between a power supply line and an inductor, a second transistor coupled between a source of the first transistor and a reference voltage line, and a third transistor coupled between the source of the first transistor and a load are included, and efficiency deterioration caused by a dead time is improved by keeping a current flow through a current path of an inductor, a load, and the third transistor during the dead time by supplying a voltage which is less than a threshold voltage and approximately the threshold voltage to a gate of the third transistor as a gate voltage.

Abstract: A semiconductor device, includes: a first field effect transistor having one terminal to which a first electrical potential is given; a second field effect transistor having one terminal to which a second electrical potential smaller than the first electrical potential is given; a controller that controls each electrical potential of each control terminal of the first field effect transistor and the second field effect transistor; a capacitor element having one end connected to the control terminal of the first field effect transistor, the capacitor element being charged by the control of the controller; and a load element connected between another terminal of the first field effect transistor and another terminal of the second field effect transistor.

Abstract: A driving circuit of a schottky type transistor includes an input terminal supplied with an input signal, and an output terminal connected to a gate of the schottky type transistor. The driving circuit outputs a first voltage lower than a breakdown voltage of the schottky type transistor to the output terminal at the time of rising of the input signal, and thereafter supplies a second voltage higher than the breakdown voltage to a resistance connected to the output terminal.

Abstract: A switching circuit device has a first transistor which has a drain coupled to a high-potential terminal, a source coupled to a low-potential power supply, and, a driving circuit, which outputs, to a gate of the first transistor in response to an input control signal, a pulse having a potential higher than a threshold voltage of the first transistor and a potential of the low-potential power supply, wherein the driving circuit has a first inverter including a second transistor provided between the gate and the source of the first transistor, wherein when the first transistor changes from on to off due to the pulse, the second transistor conducts and short-circuits the gate and the source of the first transistor.