The object of the present invention is to increase the breakdown voltage without thickening an SOI layer in a wafer-bonded dielectric isolated structure. A device region of a SiC-SOI device includes: a first trench continuously or intermittently surrounding an n.sup. type drift region and not penetrating a SiC substrate; an n.sup.+ type side surface diffusion region formed on each side surface of the first trench; an n.sup.+ type bottom diffusion region formed under the n.sup. type drift region and in contact with the n.sup.+ type side surface diffusion region; and a plurality of thin insulating films formed in proximity to a surface of the n.sup. type drift region at regular spacings of 0.4 m or less. A surrounding region includes a second trench formed to continuously surround the first trench and penetrating the SiC substrate, and an isolated insulating film region formed on each side surface of the second trench.

A semiconductor device includes a silicon carbide body including a transistor cell region and an idle region. The transistor cell region includes transistor cells. The idle region is devoid of transistor cells. The idle region includes a transition region between the transistor cell region and a side surface of the silicon carbide body, a gate pad region, and a diode structure comprising at least one of a merged pin Schottky diode structure or a merged pin heterojunction diode structure in at least one of the transition region or the gate pad region.

A semiconductor device includes a device region, including a source contact, a drain contact formed on a substrate, and a gate contact formed between the source contact and the drain contact; an isolation region surrounding the device region, the isolation region including an N-type semiconductor region formed on the substrate, a first silicide layer and a second silicide layer formed in the N-type semiconductor region and separated from each other by an isolation layer, and an anode contact and a cathode contact connected to the first silicide layer and the second silicide layer, respectively; and a Schottky barrier diode formed inside the isolation region by a junction of the first silicide layer and the N-type semiconductor region. The anode contact is connected to the source contact, and the cathode contact is connected to the drain contact.

According to one embodiment, the insulating film is provided between the anode region and the cathode region in the surface of the second semiconductor region. The third semiconductor region is provided inside the second semiconductor region. The third semiconductor region covers a corner of the insulating film on the anode region side. The first electrode contacts the anode region and the third semiconductor region. The second electrode contacts the cathode region. The third electrode is provided on the insulating film and positioned on a p-n junction between the second semiconductor region and the third semiconductor region.

A high voltage device is used as a lower switch in a power stage of a switching regulator. The high voltage device includes at least one lateral diffused metal oxide semiconductor (LDMOS) device, a first isolation region, a second isolation region, a third isolation region, and a current limiting device. The first isolation region is located in a semiconductor layer, and encloses the LDMOS device. The second isolation region has a first conductivity type, and encloses the first isolation region in the semiconductor layer. The third isolation region has a second conductivity type, and encloses the second isolation region in the semiconductor layer. The current limiting device is electrically connected to the second isolation region, and is configured to operably suppress a parasitic silicon controlled rectifier (SCR) from being turned on.

In a semiconductor device using, as a FWD, a diode formed in a silicon carbide (SiC) substrate, while preventing gate oscillation, an increase of switching loss is suppressed at the time of a temperature increase also. A semiconductor device includes: a transistor element; a diode element formed in a SiC substrate; and a resistive element that is electrically connected to a gate of the transistor element, and has a resistor temperature coefficient which is within the range of 15010.sup.6/K. The resistive element has a resistor formed of a ceramic-containing material.

Disclosed is a semiconductor device, including an insulated gate field effect transistor connected in series with a field effect transistor, FET, wherein the FET includes several parallel conductive layers, and wherein a substrate is arranged as the basis for the semiconductor device, stretching under both transistors, and a first n-type layer is arranged stretching over the substrate, and further wherein on top of this first n-type layer are arranged several conductive layers with channels formed by several n-type doped epitaxial layers with p-type doped gates on both sides.

An embodiment of the invention shows a high-voltage MOS field-effect transistor connected in series with a Schottky diode. When the Schottky diode is forwardly biased, the high-voltage MOSFET can act as a switch and sustain a high drain-to-source voltage. When the Schottky diode is reversely biased, the Schottky diode can protect the integrate circuit where the high-voltage MOSFET is formed, because the integrate circuit might otherwise burn out due to an exceedingly-large reverse current.

The invention provides a power device, which includes: an operation layer, including a top surface, a body region and a drift region, the body region and the drift region being connected in a lateral direction, to form a PN junction along a channel width direction between the body region and the drift region; a gate, formed on the top surface, and the PN junction is located under the gate; a source, formed in a portion of the operation layer between the body region and the top surface; a drain, formed in another portion of the operation layer between the drift region and the top surface; a first conduction portion, formed on the top surface for electrically connecting the source; a conduction layer, formed on the first conduction portion and electrically connected to the source via the first conduction portion; and a second conduction portion, formed on the top surface and between the conduction layer and the drift region in a thickness direction, for electrically connecting the drift region and the conduction layer, wherein a Schottky diode is formed by the second conduction portion and the drift region.

A semiconductor device including a substrate, an isolation structure, a diode element, and a first metal layer is provided. The isolation structure is located in the substrate. The diode element is located on the isolation structure. The diode element includes a p-type doped region, an n-type doped region, and an intrinsic region, and the intrinsic region is located between the p-type doped region and the n-type doped region. The p-type doped region and the n-type doped region located on two sides of the diode element respectively form ohmic contacts. The first metal layer and the intrinsic region of the diode element are electrically connected and form a Schottky contact, so as to constitute at least one Schottky barrier diode.