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.

Disclosed is a gate control circuit that generates a gate control signal of an output transistor connected between an application end of a power supply voltage and an application end of an output voltage. The gate control circuit includes a first current source connected between the application end of the power supply voltage and the application end of the output voltage, a second current source connected between an application end of a booster voltage and an application end of a reference voltage, the booster voltage being raised to a voltage value higher than the power supply voltage in a steady state, an output stage that uses at least one of the first and second current sources to generate a gate charge current for charging a gate of the output transistor, and a controller that uses at least one of the first and second current sources according to the output voltage.

A low voltage transient voltage suppressing (TVS) device supported on a semiconductor substrate supporting an epitaxial layer to form a bottom-source metal oxide semiconductor field effect transistor (BS-MOSFET) that comprises a trench gate surrounded by a drain region encompassed in a body region disposed near a top surface of the semiconductor substrate. The drain region interfaces with the body region constituting a junction diode. The drain region on top of the epitaxial layer constituting a bipolar transistor with a top electrode disposed on the top surface of the semiconductor functioning as a drain/collector terminal and a bottom electrode disposed on a bottom surface of the semiconductor substrate functioning as a source/emitter electrode. The body regions further comprises a surface body contact region electrically connected to a body-to-source short-connection thus connecting the body region to the bottom electrode functioning as the source/emitter terminal.

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 drain contact on opposing sides of the epitaxial layer of the source contact, 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, wherein the breakdown voltage enhancement and leakage prevention structure comprises a body ring structure.

A synchronous rectifier is described that includes a transistor device that has a gate terminal, a source terminal, a drain terminal, and a field-plate electrode. The field-plate electrode of the transistor device includes an integrated diode. The integrated diode is configured to discharge a parasitic capacitance of the transistor device during each switching operation of the synchronous rectifier. In some examples, the integrated diode is also configured to charge the parasitic capacitance of the transistor device during each switching operation of the synchronous rectifier.

A semiconductor device has an FET of a trench-gate structure obtained by disposing a conductive layer, which will be a gate, in a trench extended in the main surface of a semiconductor substrate, wherein the upper surface of the trench-gate conductive layer is formed equal to or higher than the main surface of the semiconductor substrate. The conductive layer of the trench gate is formed to have a substantially flat or concave upper surface and the upper surface is formed equal to or higher than the main surface of the semiconductor substrate. After etching of the semiconductor substrate to form the upper surface of the conductive layer of the trench gate, a channel region and a source region are formed by ion implantation so that the semiconductor device is free from occurrence of a source offset.

A semiconductor device includes a first electrode, a first semiconductor layer of a first dopant type on the first electrode. A first region of the semiconductor device includes a second semiconductor layer of the second dopant type on the first semiconductor layer, a third semiconductor layer of the first dopant type on the second semiconductor layer, and a second electrode extending though the second and third semiconductor layers and inwardly of the first semiconductor layer. A second region of the semiconductor device includes an insulating layer over the first semiconductor layer, a fourth semiconductor layer of the first or second dopant type on the insulating layer, a fifth semiconductor layer of a different dopant type on the insulating layer and surrounding the fourth semiconductor layer, and a sixth semiconductor layer of the same dopant type on the insulation layer and surrounding the fifth semiconductor layer.

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 semiconductor substrate of a first conductivity type, a first semiconductor layer of the first conductivity type, a second semiconductor layer of a second conductivity type, first semiconductor regions of the first conductivity type, second semiconductor regions of the second conductivity type, gate insulating films, gate electrodes, an insulating film, first electrodes, a second electrode, and trenches. The first semiconductor regions and the second semiconductor regions are periodically disposed apart from one another in a first direction in which the trenches extend in a stripe pattern.

A method includes growing an epitaxial layer over a substrate, forming a plurality of gates in the epitaxial layer, forming a source in the epitaxial layer, forming a breakdown voltage enhancement and leakage prevention structure comprising a body ring structure in the epitaxial layer, forming a gate-source Electrostatic Discharge (ESD) diode structure over the epitaxial layer, forming a source contact connected to the source and a first terminal of the gate-source ESD diode structure, forming a gate contact connected to the plurality of gates and a second terminal of the gate-source ESD diode structure.