Abstract: According to one embodiment, the gate insulating film is provided on a semiconductor region including the body region and the drift region between the source region and the drain region. The gate insulating film includes a first part and a second part. The first part is provided on the source region side. The second part is provided on the drain region side and thicker than the first part. The insulating portion is provided in the semiconductor region under a boundary between the first part and the second part of the gate insulating film.

Abstract: A semiconductor device according to an embodiment includes a first semiconductor region of a first conductivity type, a second semiconductor region of a second conductivity type in contact with the first semiconductor region, a third semiconductor region of the first conductivity type in contact with the second semiconductor region and spaced from the first semiconductor region, a first insulating film provided between the first semiconductor region and the third semiconductor region on the second semiconductor region, a first electrode provided on the first insulating film, a high-pass filter connected between the first semiconductor region and the third semiconductor region, and a low-pass filter connected between the second semiconductor region and the third semiconductor region.

Abstract: A semiconductor device such as, for example, a diode is described. The semiconductor device includes a first conductivity type substrate layer. A second conductivity-type first semiconductor layer is in a first conductivity-type substrate layer. A first conductivity-type second semiconductor layer is in the first semiconductor layer and separated from the substrate layer. A second conductivity-type third semiconductor layer is in the second semiconductor layer. A first conductivity-type fourth semiconductor layer is in the third semiconductor layer. A first conductivity-type fifth semiconductor layer is in the third semiconductor layer and separated from the fourth semiconductor layer. A second conductivity-type sixth semiconductor layer is in the third semiconductor layer and separated from the fourth semiconductor layer. A first electrode is connected to the fourth semiconductor layer. And a second electrode is connected to the fifth semiconductor layer and the sixth semiconductor layer.

Abstract: An electrostatic discharge protection circuit includes a first trigger circuit outputting a first trigger signal according to a first time constant and a voltage applied between power source lines. A second trigger circuit outputs a second trigger signal according to the voltage between the power source lines and a second time constant that is greater than the first time constant. A holding circuit outputs a shunt control signal in accordance with the first trigger signal and a reset signal supplied from a reset circuit in accordance with the second trigger signal. A shunt circuit is connected between the power source lines and provides a conductance path between the power source lines in accordance with the shunt control signal.

Abstract: A circuit that protects against ESD and avoids an excessive power voltage drop during the protection operation includes a control circuit that is connected between power terminals and outputs a control signal when a voltage between the power terminals exceeds a predetermined value due to a surge current, and an asymmetric current transfer device including a PN junction reverse-biased by the power voltage between the power terminals, that is connected in series with the output current channel of a shunt transistor. The conductivity of the shunt transistor is controlled according to the control signal.

Abstract: According to one embodiment, an electrostatic protection circuit includes a first trigger circuit that is connected between a first power supply terminal and a second power supply terminal, and a second trigger circuit. The circuit includes a first buffer circuit that outputs a drive signal in response to a trigger signal of the first trigger circuit, and a second buffer circuit that outputs a drive signal in response to a trigger signal of the second trigger circuit. A shunt circuit includes a first switch circuit and a second switch circuit connected in series between the first and second power supply terminals. A conduction of the first switch circuit is controlled by a drive signal of the first buffer circuit, and a conduction of the second switch circuit is controlled by a drive signal of the second buffer circuit.

Abstract: A semiconductor device for protecting loads from power surges includes a first resistor having a first end connected to a first supply terminal, a capacitor connected to a second end of the first resistor and a second supply terminal. There is a first transistor with a source connected to the first supply terminal and a gate connected to a point between the first resistor and the capacitor. A second resistor is connected between the drain of the first transistor and the second supply terminal, and a first diode is connected between the gate and the source of the first transistor. A second transistor has a drain connected to the first supply terminal, a source connected to the second supply terminal, and a gate connected to the drain of the first transistor. There is a second diode connected between the gate and the source of the second transistor.

Abstract: An electrostatic protection circuit includes a clamp circuit between a first power source line and a trigger circuit. The clamp circuit has a threshold voltage at which the response to changes in voltage becomes non-linear such that electric current passing through the clamp circuit varies non-linearly. The trigger circuit is connected between the clamp circuit and a second power source line. The trigger circuit outputs a trigger signal to a buffer circuit according to the electric current passing through the clamp circuit. The buffer circuit is configured to output a drive signal to a switch circuit in response to the trigger signal. The switch circuit has a main current path connected between the first power source line and the second power source line, and switches the conduction state of the main current path in response to the drive signal.

Abstract: According to one embodiment, a semiconductor device including a field-effect transistor, and a resistance element connected between a gate electrode of the field effect transistor and a connection point connected between a back gate electrode of the field effect transistor and one of source-drain regions of the field effect transistor, a voltage being applied between the other of the source-drain regions and the gate electrode.

Abstract: A circuit that protects against ESD and avoids an excessive power voltage drop during the protection operation includes a control circuit that is connected between power terminals and outputs a control signal when a voltage between the power terminals exceeds a predetermined value due to a surge current, and an asymmetric current transfer device including a PN junction reverse-biased by the power voltage between the power terminals, that is connected in series with the output current channel of a shunt transistor. The conductivity of the shunt transistor is controlled according to the control signal.

Abstract: A semiconductor device for protecting loads from power surges includes a first resistor having a first end connected to a first supply terminal, a capacitor connected to a second end of the first resistor and a second supply terminal. There is a first transistor with a source connected to the first supply terminal and a gate connected to a point between the first resistor and the capacitor. A second resistor is connected between the drain of the first transistor and the second supply terminal, and a first diode is connected between the gate and the source of the first transistor. A second transistor has a drain connected to the first supply terminal, a source connected to the second supply terminal, and a gate connected to the drain of the first transistor. There is a second diode connected between the gate and the source of the second transistor.

Abstract: A semiconductor device includes a first interconnect connected to a high voltage side power supply voltage, a second interconnect connected to the high voltage side power supply voltage, a switching transistor, and a protective element connected in parallel with the switching transistor between the high voltage side power supply voltage and a low voltage side power supply voltage. A first end of the switching transistor is connected to the first interconnect, and a second end is connected to an output terminal. The protective element includes a first p-type semiconductor region connected to the first interconnect, an n-type semiconductor region in contact with the first p-type semiconductor region and connected to the second interconnect, and a second p-type semiconductor region in contact with the n-type semiconductor region, spaced from the first p-type semiconductor region, and connected to the low voltage side power supply voltage.

Abstract: A semiconductor device includes a first interconnect connected to a high voltage side power supply voltage, a second interconnect connected to the high voltage side power supply voltage, a switching transistor, and a protective element connected in parallel with the switching transistor between the high voltage side power supply voltage and a low voltage side power supply voltage. A first end of the switching transistor is connected to the first interconnect, and a second end is connected to an output terminal. The protective element includes a first p-type semiconductor region connected to the first interconnect, an n-type semiconductor region in contact with the first p-type semiconductor region and connected to the second interconnect, and a second p-type semiconductor region in contact with the n-type semiconductor region, spaced from the first p-type semiconductor region, and connected to the low voltage side power supply voltage.

Abstract: According to one embodiment, a semiconductor device includes a p-type semiconductor layer, an n-type source region, an insulator, an n-type semiconductor region, an n-type drain region, a p-type channel region, a gate insulating film, a gate electrode, a source electrode, a drain electrode, and an electrode. The source region is provided on a surface of the p-type semiconductor layer. The insulator is provided in a trench formed extending in a thickness direction of the p-type semiconductor layer from the surface of the p-type semiconductor layer. The n-type semiconductor region is provided on the surface of the p-type semiconductor layer between the source region and the insulator. The drain region is provided on the surface of the p-type semiconductor layer between the source region and the n-type semiconductor region and separated from the source region and the n-type semiconductor region.

Abstract: According to one embodiment, a semiconductor device including a field-effect transistor, and a resistance element connected between a gate electrode of the field effect transistor and a connection point connected between a back gate electrode of the field effect transistor and one of source-drain regions of the field effect transistor, a voltage being applied between the other of the source-drain regions and the gate electrode.