A semiconductor device includes a first-conductivity-type semiconductor layer including an active region in which a transistor having impurity regions is formed and a marginal region surrounding the active region, a second-conductivity-type channel layer formed between the active region and the marginal region and forming a front surface of the semiconductor layer, at least one gate trench formed in the active region to extend from the front surface of the semiconductor layer through the channel layer, a gate insulation film formed on an inner surface of the gate trench, a gate electrode formed inside the gate insulation film in the gate trench, and at least one isolation trench arranged between the active region and the marginal region to surround the active region and extending from the front surface of the semiconductor layer through the channel layer, the isolation trench having a depth equal to that of the gate trench.

A semiconductor device includes a first load terminal electrically coupled to a source zone of a transistor cell. A gate terminal is electrically coupled to a gate electrode which is capacitively coupled to a body zone of the transistor cell. The source and body zones are formed in a semiconductor portion. A thermoresistive element is thermally connected to the semiconductor portion and is electrically coupled between the gate terminal and the first load terminal. Above a maximum operation temperature specified for the semiconductor device, an electric resistance of the thermoresistive element decreases by at least two orders of magnitude within a critical temperature span of at most 50 Kelvin.

According to one embodiment, a semiconductor device, includes an element unit including a vertical-type MOSFET, the vertical-type MOSFET in including a first semiconductor layer, a second semiconductor layer, a third semiconductor layer, a fourth semiconductor layer, a fifth semiconductor layer sequentially stacked in order, an impurity concentration of the second semiconductor layer being lower than the first semiconductor layer, an insulator covering inner surfaces of a plurality of trenches, the adjacent trenches being provided with a first interval in between, and a diode unit including basically with the units of the element unit, the adjacent trenches being provided with a second interval in between, the second interval being larger than the first interval.

A semiconductor device having a field-effect transistor, including a trench in a semiconductor substrate, a first insulating film in the trench, an intrinsic polycrystalline silicon film over the first insulating film, and first conductivity type impurities in the intrinsic polycrystalline silicon film to form a first conductive film. The first conductive film is etched to form a first gate electrode in the trench. A second insulating film is also formed in the trench above the first insulating film and the first gate electrode, and a first conductivity type doped polycrystalline silicon film, having higher impurity concentration than the first gate electrode is formed over the second insulating film. The doped polycrystalline silicon film is provided in an upper part of the trench to form a second gate electrode.

A capacitive component region is formed below a temperature detecting diode or below a protective diode. In addition, the capacitive component region is formed below an anode metal wiring line connecting the temperature detecting diode and an anode electrode pad and below a cathode metal wiring line connecting the temperature detecting diode and a cathode electrode pad. The capacitive component region is an insulating film interposed between polysilicon layers. Specifically, a first insulating film, a polysilicon conductive layer, and a second insulating film are sequentially formed on a first main surface of a semiconductor substrate, and the temperature detecting diode, the protective diode, the anode metal wiring line, or the cathode metal wiring line is formed on the upper surface of the second insulating film. Therefore, it is possible to improve the static electricity resistance of the temperature detecting diode or the protective diode.

A semiconductor device manufacturing method includes: forming a first groove having depth H in a semiconductor layer; filling the first groove with an oxide film and forming a surface oxide film having thickness a on an upper surface of the semiconductor layer to equalize the oxide film and the surface oxide film in height; forming a second groove having depth h greater than thickness a, from an uppermost surface of a third oxide film; forming gate trenches deeper than depth H, in the semiconductor layer; depositing polysilicon until at least the gate trenches and the second groove are filled with polysilicon; forming a peripheral element by injecting an impurity into polysilicon deposited in the second groove; and making a thickness of the peripheral element equal to depth h by concurrently removing polysilicon deposited in the gate trenches and polysilicon deposited in the second groove until they become equal in height.

An apparatus includes a drain and a source on opposing sides of an epitaxial layer, a plurality of gates formed in the epitaxial layer, a source contact connected to the source, a gate contact connected to the plurality of gates, a gate-source electrostatic discharge (ESD) diode connected between the gate contact and the source contact, and a breakdown voltage enhancement and leakage prevention structure formed underneath the gate-source ESD diode structure.

A semiconductor device includes: a split-gate transistor connected between a drain electrode (output electrode OUT) and a ground electrode and having a plurality of individually controllable channel regions; an active clamp circuit configured to limit the output voltage VOUT appearing at the output electrode to a clamp voltage or below; and a gate control circuit configured to raise the ON resistance of the split-gate transistor gently (or stepwise) after the split-gate transistor is switched from the ON state to the OFF state before the active clamp circuit limits the output voltage VOUT.

An apparatus includes a drain and a source on opposing sides of an epitaxial layer, a plurality of gates formed in the epitaxial layer, a source contact connected to the source, a gate contact connected to the plurality of gates, a gate-source electrostatic discharge (ESD) diode connected between the gate contact and the source contact, and a breakdown voltage enhancement and leakage prevention structure formed underneath the gate-source ESD diode structure.

An apparatus includes a drain and a source on opposing sides of an epitaxial layer, a plurality of gates formed in the epitaxial layer, a source contact connected to the source, a gate contact connected to the plurality of gates, a gate-source electrostatic discharge (ESD) diode connected between the gate contact and the source contact, and a breakdown voltage enhancement and leakage prevention structure formed underneath the gate-source ESD diode structure.