Abstract: A semiconductor device includes: a semiconductor substrate; an interlayer film on the substrate; a surface electrode on the interlayer film; a surface pad on the surface electrode; a backside electrode on the substrate; an element area including a cell portion having a vertical semiconductor element and a removal portion having multiple contact regions; and an outer periphery area. The surface electrode in the removal portion is electrically coupled with each contact region through a first contact hole in the interlayer film. The surface electrode in the cell portion is electrically coupled with the substrate through a second contact hole in the interlayer film. A part of the surface electrode in the removal portion facing each contact region is defined as a contact portion. The surface electrode includes multiple notches on a shortest distance line segment between each contact portion and the surface pad.

Abstract: The present invention relates to a switch circuit, and more particularly, to a switch circuit that uses an LDMOS (lateral diffusion metal oxide semiconductor) device inside an IC (Integrated Circuit). In the switch circuit that uses the LDMOS device according to an embodiment of the present invention, a gate-source voltage (VGS) of the LDMOS device may be stably controlled through a current source and resistances, the characteristics of a switch may be maintained regardless of the voltages of both terminals (A and B) by using an N-type LDMOS and a P-type LDMOS in a complementary manner, and the current generated by the current source is offset inside the switch without flowing to the outside of the switch.

Abstract: A method for forming a low Rdson LDNMOS and a high sheet resistance poly resistor and the resulting device are provided. Embodiments include forming first, second, and third STI regions in a substrate; forming a P-well in the substrate around the first STI region with a first mask; forming an N-drift region in the substrate between the P-well and the third STI region with the first mask; forming a dielectric layer over the substrate; forming a poly-silicon layer over the dielectric layer; performing an N-drain implant between the second and third STI regions with a second mask; performing a resistance adjustment implant in, but not through, the poly-silicon layer with the second mask; and patterning the poly-silicon and dielectric layers subsequent to performing the resistance adjustment implant to form a gate stack and a poly resistor, the poly resistor being formed over the third STI region and laterally separated from the gate stack.

Abstract: A transistor device includes at least one first type transistor cell including a drift region, a source region, a body region arranged between the source region and the drift region, a drain region, a gate electrode adjacent the body region and dielectrically insulated from the body region by a gate dielectric, and a field electrode adjacent the drift region and dielectrically insulated from the drift region by a field electrode dielectric. A gate terminal is coupled to the gate electrode, a source terminal is coupled to the source region, and a control terminal is configured to receive a control signal. A variable resistor is connected between the field electrode and the gate terminal or the source terminal. The variable resistor includes a variable resistance configured to be adjusted by the control signal received at the control terminal.

Abstract: On a doped well (2) for a drift section, at least two additional dielectric regions (7,9) having different thicknesses are present between a first contact region (4) for a drain and a second contact region (5) for source on the upper face (10) of the substrate (1), and the gate electrode (11) or an electric conductor, which is electrically conductively connected to the gate electrode, covers each of said additional dielectric regions at least partially.

Abstract: A static random access memory fabrication array includes at least one p-type field effect transistor, including a gate stack and isolating spacers forming a gate having a gate length Lgate and an effective gate length, Leff and a source and drain region adjacent the gate stack, wherein the source and drain regions are formed from a low extension dose implant that decreases a difference between Lgate and Leff.

Abstract: A transistor device and a manufacturing method thereof are provided. The transistor device includes a substrate, a first well, a second well, a shallow trench isolation (STI), a source, a drain and a gate. The first well is disposed in the substrate. The second well is disposed in the substrate. The STI is disposed in the second well. The STI has at least one floating diffusion island. The source is disposed in the first well. The drain is disposed in the second well. The electric type of the floating diffusion island is different from or the same with that of the drain. The gate is disposed above the first well and the second well, and partially overlaps the first well and the second well.

Abstract: A semiconductor device includes a first conduction type semiconductor substrate, a first conduction type semiconductor deposition layer, a trench, second conduction type wells, a JFET region, a first conduction type first source region, a first source region, a trench-type source electrode, a gate insulator film, a gate electrode, and a drain electrode. The trench is formed substantially perpendicularly to the semiconductor deposition layer so that the semiconductor deposition layer exposes to a bottom of the trench. The second conduction type second source region are formed in the first conduction type first source region. The trench-type source electrode is in contact with the first source region, the second source region, and the first conduction type semiconductor deposition layer to configure a Schottky junction.

Abstract: A device includes a substrate and insulation regions over a portion of the substrate. A first semiconductor region is between the insulation regions and having a first conduction band. A second semiconductor region is over and adjoining the first semiconductor region, wherein the second semiconductor region includes an upper portion higher than top surfaces of the insulation regions to form a semiconductor fin. The second semiconductor region also includes a wide portion and a narrow portion over the wide portion, wherein the narrow portion is narrower than the wide portion. The semiconductor fin has a tensile strain and has a second conduction band lower than the first conduction band. A third semiconductor region is over and adjoining a top surface and sidewalls of the semiconductor fin, wherein the third semiconductor region has a third conduction band higher than the second conduction band.

Abstract: Integrated circuit devices with field effect transistors have source and drain regions that include a first and a second layer. The first layer is formed below the plane of the channel region. The first layer includes doped silicon and carbon that has a crystal lattice structure that is smaller than that of silicon. The second layer is formed over the first layer and rises above the plane of the channel region. The second layer is formed by a material that includes doped epitaxially grown silicon. The second layer has an atomic fraction of carbon less than half that of the first layer. The first layer is formed to a depth at least 10 nm below the surface of the channel region. This structure facilitates the formation of source and drain extension areas that form very shallow junctions. The devices provide sources and drains that have low resistance while being comparatively resistant to short channel effects.

Abstract: A device includes a substrate, a body region in the substrate and having a first conductivity type, source and drain regions in the substrate, having a second conductivity type, and spaced from one another to define a conduction path that passes through the body region, a doped isolating region in the substrate, having the second conductivity type, and configured to surround a device area in which the conduction path is disposed, an isolation contact region in the substrate, having the second conductivity type, and electrically coupled to the doped isolating region to define a collector region of a bipolar transistor, and first and second contact regions within the body region, having the first and second conductivity types, respectively, and configured to define a base contact region and an emitter region of the bipolar transistor, respectively.

Abstract: A semiconductor device is formed with a stepped field plate over at least three sequential regions in which a total dielectric thickness under the stepped field plate is at least 10 percent thicker in each region compared to the preceding region. The total dielectric thickness in each region is uniform. The stepped field plate is formed over at least two dielectric layers, of which at least all but one dielectric layer is patterned so that at least a portion of a patterned dielectric layer is removed in one or more regions of the stepped field plate.

Abstract: A device includes a semiconductor region in a semiconductor chip, a gate dielectric layer over the semiconductor region, and a gate electrode over the gate dielectric. A drain region is disposed at a top surface of the semiconductor region and adjacent to the gate electrode. A gate spacer is on a sidewall of the gate electrode. A dielectric layer is disposed over the gate electrode and the gate spacer. A conductive field plate is over the dielectric layer, wherein the conductive field plate has a portion on a drain side of the gate electrode. A deep metal via is disposed in the semiconductor region. A source electrode is underlying the semiconductor region, wherein the source electrode is electrically shorted to the conductive field plate through the deep metal via.

Abstract: It is the purpose of the invention to provide a MOS transistor (20) which guarantees a voltage as high as possible, has a required area as small as possible and which enables the integration into integrated smart power circuits. It results there from as an object of the invention to form the edge structure of the transistors such that it certainly fulfils the requirements on high breakthrough voltages, a good isolation to the surrounding region and requires a minimum of surface on the silicon disc anyway. This is achieved with an elongated MOS power transistor having drain (30) and source (28) for high rated voltages above 100V, wherein the transistor comprises an isolating trench (22) in the edge area for preventing an early electrical breakthrough below the rated voltage. The trench is lined with an isolating material (70, 72), wherein the isolating trench terminates the circuit component.

Abstract: A method of manufacturing a memory device includes an nMOS region and a pMOS region in a substrate. A first gate is defined within the nMOS region, and a second gate is defined in the pMOS region. Disposable spacers are simultaneously defined about the first and second gates. The nMOS and pMOS regions are selectively masked, one at a time, and LDD and Halo implants performed using the same masks as the source/drain implants for each region, by etching back spacers between source/drain implant and LDD/Halo implants. All transistor doping steps, including enhancement, gate and well doping, can be performed using a single mask for each of the NMOS and pMOS regions. Channel length can also be tailored by trimming spacers in one of the regions prior to source/drain doping.

Abstract: Semiconductor layers on active areas for transistors in a memory cell region (region A) and a peripheral circuit region (region B) are simultaneously epitaxially grown in the same thickness in which the adjacent semiconductor layers in region A do not come into contact with each other. Only semiconductor layer (10) in region B is also grown from the surface of a substrate which is exposed when only the surface of STI (2) in region B is drawn back, so that a facet (F) of the semiconductor layer 10 is formed outside the active area, followed by ion-implantation to form a high density diffusion layer (11) in region B. Accordingly, short circuit between semiconductor layers on source/drain electrodes of transistors in region A is prevented, and uniformity of the junction depth of the layer (11) of the source/drain electrodes including an ESD region in a transistor of region B is obtained, thereby restricting the short channel effect.

Abstract: Provided are a semiconductor device including a high voltage transistor and a low voltage transistor and a method of manufacturing the same. The semiconductor device includes a semiconductor substrate including a high voltage region and a low voltage region; a high voltage transistor formed in the high voltage region and including a first active region, a first source/drain region, a first gate insulating layer, and a first gate electrode; and a low voltage transistor formed in the low voltage region and including a second active region, a second source/drain region, a second gate insulating layer, and a second gate electrode. The second source/drain region has a smaller thickness than a thickness of the first source/drain region.

Abstract: A transistor advantageously embodied in a laterally diffused metal oxide semiconductor device having a gate located over a channel region recessed into a semiconductor substrate and a method of forming the same. In one embodiment, the laterally diffused metal oxide semiconductor device includes a source/drain having a lightly doped region located adjacent the channel region and a heavily doped region located adjacent the lightly doped region. The laterally diffused metal oxide semiconductor device further includes an oppositely doped well located under and within the channel region, and a doped region, located between the heavily doped region and the oppositely doped well, having a doping concentration profile less than a doping concentration profile of the heavily doped region.

Abstract: A lateral-diffused metal oxide semiconductor device (LDMOS) includes a substrate, a first deep well, at least a field oxide layer, a gate, a second deep well, a first dopant region, a drain and a common source. The substrate has the first deep well which is of a first conductive type. The gate is disposed on the substrate and covers a portion of the field oxide layer. The second deep well having a second conductive type is disposed in the substrate and next to the first deep well. The first dopant region having a second conductive type is disposed in the second deep well. The doping concentration of the first dopant region is higher than the doping concentration of the second deep well.

Abstract: A semiconductor device includes a laterally double diffused metal oxide semiconductor (LDMOS) transistor formed on a partial region of a epitaxial layer of a first conductive type, a bipolar transistor formed on another partial region of the epitaxial layer of the first conductive type, and a guard ring formed between the partial region and the another partial region. The guard ring serves to restrain electrons generated by a forward bias operation of the LDMOS transistor from being introduced into the bipolar transistor.

Abstract: A method of manufacturing a diode is provided. An N-type well region is formed in a first upper portion of an N-type epitaxial layer. A P-type drift region is formed in a second upper portion of the N-type epitaxial layer. An N-type doping region is formed in the N-type well region. A P-type doping region is formed in the P-type drift region. An isolation structure is formed in the P-type drift region. The isolation structure is disposed between the P-type doping region and the N-type well region. A first electrode is formed on a portion of the N-type epitaxial layer. The portion of the N-type epitaxial layer is disposed between the N-type well region and the P-type drift region. The first electrode overlaps a portion of the isolation structure. A connection structure is formed to electrically couple the N-type doping region and the first electrode.

Abstract: A semiconductor device containing a high voltage MOS transistor with a drain drift region over a lower drain layer and channel regions laterally disposed at the top surface of the substrate. RESURF trenches cut through the drain drift region and body region parallel to channel current flow. The RESURF trenches have dielectric liners and electrically conductive RESURF elements on the liners. Source contact metal is disposed over the body region and source regions. A semiconductor device containing a high voltage MOS transistor with a drain drift region over a lower drain layer, and channel regions laterally disposed at the top surface of the substrate. RESURF trenches cut through the drain drift region and body region perpendicular to channel current flow. Source contact metal is disposed in a source contact trench and extended over the drain drift region to provide a field plate.

Abstract: An electronic semiconductor device comprising: a semiconductor body, having a first side and a second side opposite to one another and including a first structural region facing the second side, and a second structural region extending over the first structural region and facing the first side; a body region extending in the second structural region at the first side; a source region extending inside the body region; an LDD region facing the first side of the semiconductor body; and a gate electrode. The device comprises: a trench dielectric region extending through the second structural region a first trench conductive region immediately adjacent to the trench dielectric region; and a second trench conductive region in electrical contact with the body region and with the source region. An electrical contact at the second side of the semiconductor body is in electrical contact with the drain region via the first structural region.

Abstract: A method of forming a device includes forming a buried well region of a first dopant type in a substrate. A well region of the first dopant type is formed over the buried well region. A first well region of a second dopant type is formed between the well region of the first dopant type and the buried well region of the first dopant type. A second well region of the second dopant type is formed in the well region of the first dopant type. An isolation structure is formed at least partially in the well region of the first dopant type. A first gate electrode is formed over the isolation structure and the second well region of the second dopant type.

Abstract: An integrated circuit containing a MOS transistor and a DEMOS transistor of a same polarity may be formed by implanting dopants of a same conductivity type as source/drain regions of the MOS transistor and the DEMOS transistor through a gate of the MOS transistor and through a gate of the DEMOS transistor. The implanted dopants are blocked from a drain-side edge of the DEMOS transistor gate. The implanted dopants form a drain enhancement region under the DEMOS transistor gate in a drift region of an extended drain of the DEMOS transistor.

Abstract: A semiconductor device includes a transistor, formed in a semiconductor substrate having a first main surface. The transistor includes a channel region, doped with dopants of a first conductivity type, a source region, a drain region, the source and the drain region being doped with dopants of a second conductivity type different from the first conductivity type, a drain extension region, and a gate electrode adjacent to the channel region. The channel region is disposed in a first portion of a ridge. The drain extension region is disposed in a second portion of the ridge, and includes a core portion doped with the first conductivity type. The drain extension region further includes a cover portion doped with the second conductivity type, the cover portion being adjacent to at least one or two sidewalls of the second portion of the ridge.

Abstract: A metal-oxide-semiconductor (MOS) device is disclosed. The MOS device includes a substrate of a first impurity type, a diffused region of a second impurity type in the substrate, a patterned first dielectric layer including a first dielectric portion over the diffused region, a patterned first conductive layer on the patterned first dielectric layer, the patterned first conductive layer including a first conductive portion on the first dielectric portion, a patterned second dielectric layer including a second dielectric portion that extends on a first portion of an upper surface of the first conductive portion and along a sidewall of the first conductive portion to the substrate; and a patterned second conductive layer on the patterned second dielectric layer, the patterned second conductive layer including a second conductive portion on the second dielectric portion.

Abstract: Embodiments of the present disclosure provide techniques and configurations associated with conversion of thin transistor elements from silicon (Si) to silicon germanium (SiGe). In one embodiment, a method includes providing a semiconductor substrate having a channel body of a transistor device disposed on the semiconductor substrate, the channel body comprising silicon, forming a cladding layer comprising germanium on the channel body, and annealing the channel body to cause the germanium to diffuse into the channel body. Other embodiments may be described and/or claimed.

Abstract: A planar transistor with improved performance has a source and a drain on a semiconductor substrate that includes a substantially undoped channel extending between the source and the drain. A gate is positioned over the substantially undoped channel on the substrate. Implanted source/drain extensions contact the source and the drain, with the implanted source/drain extensions having a dopant concentration of less than about 1×1019 atoms/cm3, or alternatively, less than one-quarter the dopant concentration of the source and the drain.

Abstract: An advanced transistor with punch through suppression includes a gate with length Lg, a well doped to have a first concentration of a dopant, and a screening region positioned under the gate and having a second concentration of dopant. The second concentration of dopant may be greater than 5×1018 dopant atoms per cm3. At least one punch through suppression region is disposed under the gate between the screening region and the well. The punch through suppression region has a third concentration of a dopant intermediate between the first concentration and the second concentration of dopant. A bias voltage may be applied to the well region to adjust a threshold voltage of the transistor.

Abstract: An electronic power component including a normally on high-voltage transistor and a normally off low-voltage transistor. The normally on transistor and the normally off transistor are coupled in cascode configuration and are housed in a single package. The normally off transistor is of the bottom-source type.

Abstract: The present invention discloses a high voltage device and a manufacturing method thereof. The high voltage device is formed in a well of a substrate. The high voltage device includes: a field oxide region; a gate, which is formed on a surface of the substrate, and part of the gate is located above the field oxide region; a source and a drain, which are formed at two sides of the gate respectively; and a first low concentration doped region, which is formed beneath the gate and has an impurity concentration which is lower than that of the well surrounded, wherein from top view, the first low concentration doped region has an area within the gate and not larger than an area of the gate, and the first low concentration doped region has a depth which is deeper than that of the source and drain.

Abstract: Semiconductor device structures and related fabrication methods are provided. An exemplary semiconductor device structure includes a first vertical drift region of semiconductor material, a second vertical drift region of semiconductor material, and a buried lateral drift region of semiconductor material that abuts the vertical drift regions. In one or more embodiments, the vertical drift regions and buried lateral drift region have the same conductivity type, wherein a body region of the opposite conductivity type overlies the buried lateral drift region between the vertical drift regions.

Abstract: The present technology discloses a U-shape RESURF MOSFET device. Wherein the MOSFET device comprises a drain having a drain contact region and a drift region, a source, a body, a gate and a recessed-FOX structure. Wherein the recessed-FOX structure is between the gate and the drift region vertically and between the body and the drain contact region laterally, and wherein the recessed-FOX structure is configured to make the drift region into a U shape. The present technology further discloses the depth of the drift region is controlled by adjusting a layout width.

Abstract: A semiconductor device and method of forming the same including, in one embodiment, a semiconductor die formed with a plurality of laterally diffused metal oxide semiconductor (“LDMOS”) cells, and a metallic layer electrically coupled to the plurality of LDMOS cells. The semiconductor device also includes a plurality of gate drivers positioned along a periphery of the semiconductor die and electrically coupled to gates of the plurality of LDMOS cells through the metallic layer.

Abstract: A semiconductor device includes a substrate with one or more active regions and an isolation layer formed to surround an active region and to extend deeper into the substrate than the one or more active regions. The semiconductor further includes a gate electrode, which covers a portion of the active region, and which has one end portion thereof extending over the isolation layer.

Abstract: A semiconductor device and method of forming the same including, in one embodiment, a semiconductor die formed with a plurality of laterally diffused metal oxide semiconductor (“LDMOS”) cells. The semiconductor device also includes a redistribution layer electrically coupled to the plurality of LDMOS cells and a plurality of metallic pillars distributed over and electrically coupled to the redistribution layer.

Abstract: The present invention discloses a hybrid high voltage device and a manufacturing method thereof. The hybrid high voltage device is formed in a first conductive type substrate, and includes at least one lateral double diffused metal oxide semiconductor (LDMOS) device region and at least one vent device region, wherein the LDMOS device region and the vent device region are connected in a width direction and arranged in an alternating order. Besides, corresponding high voltage wells, sources, drains, body regions, and gates of the LDMOS device region and the vent device region are connected to each other respectively.

Abstract: In a semiconductor chip in which LDMOSFET elements for power amplifier circuits used for a power amplifier module are formed, a source bump electrode is disposed on an LDMOSFET formation region in which a plurality of source regions, a plurality of drain regions and a plurality of gate electrodes for the LDMOSFET elements are formed. The source bump electrode is formed on a source pad mainly made of aluminum via a source conductor layer which is thicker than the source pad and mainly made of copper. No resin film is interposed between the source bump electrode and the source conductor layer.

Abstract: An integrated circuit includes a high-voltage well having a first doping type, a first doped region and a second doped region embedded in the high-voltage well, the first and second doped regions having a second doping type and spaced apart by a channel in the high-voltage well, source/drain regions formed in the first doped region and in the second doped region, each of the source/drain regions having the second doping type and more heavily doped than the first and second doped regions, first isolation regions spaced apart from each of the source/drain regions, and resistance protection oxide forming a ring surrounding each of the source/drain regions.

Abstract: Disclosed is a transistor component having a control structure with a channel control layer of an amorphous semiconductor insulating material extending in a current flow direction along a channel zone.

Abstract: An ESD protection device includes a substrate of a first conductivity type, a well region of a second conductivity type, a first doped region of the second conductivity type, a second doped region of the first conductivity type, a third doped region of the second conductivity type, a fourth doped region of the first conductivity type. The well region is configured in the substrate. The first doped region is configured in the well region. The second doped region is configured in the well region and surrounding the first doped region. The third doped region is configured in the well region and surrounding the first doped region and the second doped region. The fourth doped region is configured in the well region and under the first doped region and the second doped region. The fourth doped region is coupled with the first doped region and with the second doped region, respectively.

Abstract: A semiconductor device may include a semiconductor substrate, a first conductive type well and a second conductive type drift region in the semiconductor substrate, the drift region including a first drift doping region and a second drift doping region, the second drift doping region vertically overlapping the well, and a first conductive type body region in the well, the body region being in contact with a side of the first drift doping region. The first drift doping region and the second doping region may include a first conductive type dopant and a second conductive type dopant, and an average density of the first conductive type dopant in the first drift doping region may be less than an average density of the first conductive type dopant in the second drift doping region.

Abstract: A power semiconductor device according to an embodiment includes an element portion in which MOSFET elements are provided and a termination portion provided around the element portion, and has pillar layers provided respectively in parallel to each other in a semiconductor substrate. The device includes a first trench and a first insulation film. The first trench is provided between end portions of the pillar layers, in the semiconductor substrate at the termination portion exposed from a source electrode of the MOSFET elements. The first insulation film is provided on a side surface and a bottom surface of the first trench.

Abstract: A lateral MOSFET comprises a plurality of isolation regions formed in a substrate, wherein a first isolation region is of a top surface lower than a top surface of the substrate. The lateral MOSFET further comprises a gate electrode layer having a first gate electrode layer formed over the first isolation region and a second gate electrode layer formed over the top surface of the substrate, wherein a top surface of the first gate electrode layer is lower than a top surface of the second gate electrode layer.

Abstract: Vertical capacitive depletion field effect transistors (VCDFETs) and methods for fabricating VCDFETs are disclosed. An example VCDFET includes one or more interleaved drift and gate regions. The gate region(s) may be configured to capacitively deplete the drift region(s) though one or more insulators that separate the gate region(s) from the drift region(s). The drift region(s) may have graded/non-uniform doping profiles. In addition, one or more ohmic and/or Schottky contacts may be configured to couple one or more source electrodes to the drift region(s).

Abstract: A DMOS transistor is fabricated with its source/body/deep body regions formed on the walls of a first set of trenches, and its drain regions formed on the walls of a different set of trenches. A gate region that is formed in a yet another set of trenches can be biased to allow carriers to flow from the source to the drain. Lateral current low from source/body regions on trench walls increases the active channel perimeter to a value well above the amount that would be present if the device was fabricated on just the surface of the wafer. Masking is avoided while open trenches are present. A transistor with a very low on-resistance per unit area is obtained.

Abstract: A semiconductor device includes an active region in a substrate, first to third gate structures crossing the active region and sequentially arranged parallel to each other, a first doped region in the active region between the first and second gate structures and having a first horizontal width and a first depth, and a second doped region in the active region between the second and third gate structures and having a second horizontal width and a second depth. The second horizontal width is larger than the first horizontal width and the second depth is shallower than the first depth. A distance between the first and second gate structures adjacent to each other is smaller than that between the second and third gate structures adjacent to each other. Related fabrication methods are also described.

Abstract: Disclosed is a MOSFET including at least one transistor cell. The at least one transistor cell includes a source region, a drain region, a body region and a drift region. The body region is arranged between the source region and the drift region and the drift region is arranged between the body region and the drain region. The at least one transistor cell further includes a compensation region arranged in the drift region and distant to the body region, a source electrode electrically contacting the source region and the body region, a gate electrode arranged adjacent the body region and dielectrically insulated from the body region by a gate dielectric, and a coupling arrangement including a control terminal. The coupling arrangement is configured to electrically couple the compensation region to at least one of the body region, the source region, the source electrode and the gate electrode dependent on a control signal received at the control terminal.

Abstract: A first annular isolation trench is formed in a periphery of an element region, and a second annular isolation trench is formed around the first annular isolation trench with a predetermined distance provided from the first annular isolation trench, and a semiconductor layer between the first annular isolation trench and the second annular isolation trench is separated into a plurality of portions by a plurality of linear isolation trenches formed in the semiconductor layer between the first annular isolation trench and the second annular isolation trench, and the semiconductor layer (source-side isolation region) which opposes a p-type channel layer end portion and is located between the first annular isolation trench and the second annular isolation trench is separated from other semiconductor layers (drain-side isolation regions) by the linear isolation trenches.