Abstract: The present technology is related generally to vertical discrete devices with a trench at the topside of the vertical discrete devices. The trench is filled with a conducting material. In this approach, a drain or cathode of the vertical discrete devices is electrically connected to the topside to result in a small area with low RON*AREA.

Abstract: In one embodiment, a transistor fabricated on a semiconductor die includes a first section of transistor segments disposed in a first area of the semiconductor die, and a second section of transistor segments disposed in a second area of the semiconductor die adjacent the first area. Each of the transistor segments in the first and second sections includes a pillar of a semiconductor material that extends in a vertical direction. First and second dielectric regions are disposed on opposite sides of the pillar. First and second field plates are respectively disposed in the first and second dielectric regions. Outer field plates of transistor segments adjoining first and second sections are either separated or partially merged.

Abstract: In general, according to one embodiment, a power semiconductor device includes a first semiconductor layer of a first conductivity type, a second semiconductor layer of a second conductivity type, a trench, a gate insulating film, and a gate electrode. The second semiconductor layer is provided on the first semiconductor layer. The trench is provided from the second semiconductor layer to the first semiconductor layer. The gate insulating film is composed of an oxide film and a protective layer formed on the oxide film. The protective layer is opposed to the second semiconductor layer across the oxide film in the trench. The oxide film covers the second semiconductor layer exposed at a sidewall of the trench and includes at least one of aluminum and yttrium. The gate electrode is made of n-type polysilicon buried in the trench in direct contact with the gate insulating film.

Abstract: Recessed access transistor devices used with semiconductor devices may include gate electrodes having materials with multiple work functions, materials that are electrically isolated from each other and supplied with two or more voltage supplies, or materials that create a diode junction within the gate electrode.

Abstract: A super-junction trench MOSFET with Resurf Stepped Oxide and split gate electrodes is disclosed. The inventive structure can apply additional freedom for better optimization of device performance and manufacturing capability by tuning thick oxide thickness to minimize influence of charge imbalance, trapped charges, etc. Furthermore, the fabrication method can be implemented more reliably with lower cost.

Abstract: According to one embodiment, a semiconductor device includes a first major electrode, a first semiconductor layer, a first conductivity-type base layer, a second conductivity-type base layer, a second semiconductor layer, a buried layer, a buried electrode, a gate insulating film, a gate electrode, and a second major electrode. The buried layer of the second conductivity type selectively is provided in the first conductivity-type base layer. The buried electrode is provided in a bottom portion of a trench which penetrates the second conductivity-type base layer to reach the buried layer. The buried electrode is in contact with the buried layer. The gate electrode is provided inside the gate insulating film in the trench. The second major electrode is provided on the second semiconductor layer and is electrically connected to the second semiconductor layer and the buried electrode.

Abstract: Provided is a method of manufacturing a vertical MOSFET having a trench structure, which is capable of performing stable processing. While leaving a silicon nitride film (13) used to form a trench (7) on a surface of a semiconductor substrate, a gate electrode material (9) is buried inside the trench (7), and then the gate electrode material (9) on the silicon nitride film (13) is removed, to thereby form a gate electrode (9) inside the trench (7).

Abstract: According to one embodiment, a semiconductor device includes a drift region of a first conductivity type, a base region of a second conductivity type, a source region of the first conductivity type, a gate electrode in a trench shape, a contact region of the second conductivity type, a drain electrode, and a source electrode. The drift region is selectively provided in a drain layer of the first conductivity type from a surface of the drain layer to an inside of the drain layer. The base region is selectively provided in the drift region from a surface of the drift region to an inside of the drift region. The source region is selectively provided in the base region from a surface of the base region to an inside of the base region. The gate electrode penetrates from a part of the source region through the base region adjacent to the part of the source region to reach a part of the drift region in a direction substantially parallel to a major surface of the drain layer.

Abstract: A semiconductor device and a method for manufacturing the same are disclosed. A recess gate structure is formed between an overlapping region between a gate and a source/drain so as to suppress increase in gate induced drain leakage (GIDL), and a gate insulation film is more thickly deposited in a region having weak GIDL, thereby reducing GIDL and thus improving refresh characteristics due to leakage current.

Abstract: Single transistor floating-body DRAM devices have a vertical channel transistor structure. The DRAM devices include a substrate, and first and second floating bodies disposed on the substrate and isolated from each other. A source region and a drain region are disposed under and above each of the first and second floating bodies. A gate electrode is disposed between the first and second floating bodies. Methods of fabricating the single transistor floating-body DRAM devices are also provided.

Abstract: A semiconductor device includes: a drain layer; a drift layer provided on the drain layer; a base region provided on the drift layer; a source region selectively provided on a surface of the base region; a first gate; a field-plate; a second gate; a drain electrode; and a source electrode. The first gate electrode is provided in each of a plurality of first trenches via a first insulating film. The first trenches penetrate from a surface of the source region through the base region and contact the drift layer. The field-plate electrode is provided in the first trench under the first gate electrode via a second insulating film. The second gate electrode is provided in a second trench via a third insulating film. The second trench penetrates from the surface of the source region through the base region and contacts the drift layer between the first trenches.

Abstract: A semiconductor device includes a device isolation pattern in which a polysilicon layer pattern doped with oxygen, carbon or nitrogen is interposed between an inner wall of a trench and a nitride liner. The semiconductor device includes a semiconductor substrate including a trench, a polysilicon layer pattern on a surface of the trench, a nitride layer pattern on the polysilicon layer pattern, and an insulation layer pattern on the nitride layer pattern and filling the trench. The polysilicon layer pattern may be doped with oxygen, carbon and/or nitrogen. Related manufacturing methods are also disclosed.

Abstract: A semiconductor device includes a device formation region including a plurality of unit regions arranged in series to each other, each unit region comprising first and second active regions alternately arranged in series to each other. The first active region extends in a first direction. The second active region extends obliquely to the first direction. A plurality of first semiconductor pillars is arranged in the first direction and in each of the first active regions. A second semiconductor pillar is in each of the second active regions. A first bit line includes a first diffusion layer in the device formation region. The first diffusion layer extends under the plurality of first semiconductor pillars and the second semiconductor pillar. The first bit line connects the plurality of first semiconductor pillars and the second semiconductor pillar. A second bit line is electrically connected to the second semiconductor pillar.

Abstract: A semiconductor device includes a first semiconductor pillar, a second semiconductor pillar, and a first wiring. The first semiconductor pillar includes a first diffusion region. The second semiconductor pillar is adjacent to the first semiconductor pillar. The first wiring is positioned between the first and second semiconductor pillars. The first wiring has a first metal surface. The first metal surface has an ohmic contact with the first diffusion region.

Abstract: Embodiments of the present invention relate to an improved package for a bi-directional and reverse blocking battery switch. According to one embodiment, two switches are oriented side-by-side, rather than end-to-end, in a die package. This configuration reduces the total switch resistance for a given die area, often reducing the resistance enough to avoid the use of backmetal in order to meet resistance specifications. Elimination of backmetal reduces the overall cost of the die package and removes the potential failure modes associated with the manufacture of backmetal. Embodiments of the present invention may also allow for more pin connections and an increased pin pitch. This results in redundant connections for higher current connections, thereby reducing electrical and thermal resistance and minimizing the costs of manufacture or implementation of the die package.

Abstract: According to one embodiment, a semiconductor device includes a first semiconductor layer of a first conductivity type, a second semiconductor layer of a second conductivity type, a third semiconductor layer of the first conductivity type, an embedded electrode, a control electrode, a fourth semiconductor layer of the second conductivity type, a first main electrode, and a second main electrode. The second semiconductor layer is provided on the first semiconductor layer. The third semiconductor layer is provided on the second semiconductor layer. The embedded electrode is provided in a first trench via a first insulating film. The first trench penetrates through the second semiconductor layer from a surface of the third semiconductor layer to reach the first semiconductor layer. The control electrode is provided above the embedded electrode via a second insulating film in the first trench.

Abstract: A MOS device includes first and second source/drains spaced apart relative to one another. A channel is formed in the device between the first and second source/drains. A gate is formed in the device between the first and second source/drains and proximate the channel, the gate being electrically isolated from the first and second source/drains and the channel. The gate is configured to control a conduction of the channel as a function of a potential applied to the gate. The MOS device further includes an energy filter formed between the first source/drain and the channel. The energy filter includes a superlattice structure wherein a mini-band is formed. The energy filter is operative to control an injection of carriers from the first source/drain into the channel. The energy filter, in combination with the first source/drain, is configured to produce an effective zero-Kelvin first source/drain.

Abstract: The present invention provides a technique capable of attaining an improvement in current detection accuracy in a trench gate type power MISFET equipped with a current detection circuit. Inactive cells are disposed so as to surround the periphery of a sense cell. That is, the inactive cell is provided between the sense cell and an active cell. All of the sense cell, active cell and inactive cells are respectively formed of a trench gate type power MISFET equipped with a dummy gate electrode. At this time, the depth of each trench extends through a channel forming region and is formed up to the deep inside (the neighborhood of a boundary with a semiconductor substrate) of an n-type epitaxial layer. Further, a p-type semiconductor region is provided at a lower portion of each trench. The p-type semiconductor region is formed so as to contact the semiconductor substrate.

Abstract: A semiconductor device according to the present invention includes a semiconductor layer. A first conductivity type region is formed on a base layer portion of the semiconductor layer. A body region of a second conductivity type is formed on the semiconductor layer to be in contact with the first conductivity type region. A trench in which a gate electrode is embedded through a gate insulating film is formed on the semiconductor layer. The trench penetrates through the body region, so that a deepest portion thereof reaches the first conductivity type region. A source region of the first conductivity type is formed on a surface layer portion of the semiconductor layer around the trench. The gate insulating film includes a thick-film portion having a relatively large thickness on a bottom surface of the trench.

Abstract: There is provided a high-integrated complementary metal-oxide semiconductor static random-access memory including an inverter.

Abstract: A semiconductor device includes a high-breakdown-voltage transistor having a semiconductor layer. The semiconductor layer has an element portion and a wiring portion. The element portion has a first wiring on a front side of the semiconductor layer and a backside electrode on a back side of the semiconductor layer. The element portion is configured as a vertical transistor that causes an electric current to flow in a thickness direction of the semiconductor layer between the first wiring and the backside electrode. The backside electrode is elongated to the wiring portion. The wiring portion has a second wiring on the front side of the semiconductor layer. The wiring portion and the backside electrode provide a pulling wire that allows the electric current to flow to the second wiring.

Abstract: A method for forming a field effect power semiconductor is provided. The method includes providing a semiconductor body, a conductive region arranged next to a main surface of the semiconductor body, and an insulating layer arranged on the main horizontal surface. A narrow trench is etched through the insulating layer to expose the conductive region. A polycrystalline semiconductor layer is deposited and a vertical poly-diode structure is formed. The polycrystalline semiconductor layer has a minimum vertical thickness of at least half of the maximum horizontal extension of the narrow trench. A polycrystalline region which forms at least a part of a vertical poly-diode structure is formed in the narrow trench by maskless back-etching of the polycrystalline semiconductor layer. Further, a semiconductor device with a trench poly-diode is provided.

Abstract: In a semiconductor device of the invention, a semiconductor pillar configuring a vertical MOS transistor has an upper pillar having a first width and a lower pillar having a second width. A side surface of the upper pillar is covered with a second insulation film and a third insulation film and the lower pillar is covered with a first insulation film, which is a gate insulation film, from a side surface thereof to the second insulation film. A gate electrode is insulated from an upper conductive layer by the second and third insulation films.

Abstract: In a method for manufacturing a semiconductor device, a semiconductor film formed over an insulator is doped with an impurity element to a depth less than the thickness of the semiconductor film, thereby forming an impurity doped layer; a metal silicide layer is formed on the impurity doped layer; the metal silicide layer and the semiconductor film are etched to form a recessed portion; and a layer which is not doped with the impurity element and is located at the bottom of the recessed portion of the semiconductor film is thinned to make a channel formation region. Further, a gate electrode is formed in the recessed portion over the thinned non impurity doped layer, with an insulating film interposed therebetween.

Abstract: Provided is a semiconductor device that includes a vertical MOS transistor having a trench structure capable of enhancing a driving performance of the vertical MOS transistor. A thick oxide film is formed next to a gate electrode led out of a trench of the vertical MOS transistor having the trench structure, and is removed to form a stepped portion which has a face lower than a surrounding plane and has slopes as well. This makes it possible to form a heavily doped diffusion layer right under the gate electrode through ion implantation for forming a heavily doped source diffusion layer, thereby solving a problem of no current flow in a part of a driver element and enhancing the driving performance of the vertical MOS transistor.

Abstract: A vertical semiconductor material mesa upstanding from a semiconductor base that forms a conductive channel between first and second doped regions. The first doped region is electrically coupled to one or more first silicide layers on the surface of the base. The second doped region is electrically coupled to a second silicide layer on the upper surface of the mesa. A gate conductor is provided on one or more sidewalls of the mesa.

Abstract: A gate structure includes a gate insulation layer, a gate electrode and a capping layer pattern. The gate insulation layer is formed on an inner wall of a recess in a substrate. The gate electrode is formed on the gate insulation layer to partially fill the recess. The capping layer pattern is formed of silicon oxide on the gate electrode and the gate insulation layer to fill a remaining portion of the recess.

Abstract: A semiconductor device includes a pipe channel layer formed over a substrate, a first vertical channel layer formed over the pipe channel layer to couple the pipe channel layer to a bit line, a second vertical channel layer formed over the pipe channel layer to couple the pipe channel layer to a source line, a multi-layer comprising a charge trap layer and formed to surround the first vertical channel layer, the second vertical channel layer, and the pipe channel layer, an insulating barrier layer formed to surround the multi-layer, a plurality of first conductive layers formed between the pipe channel layer and the bit line, wherein the first vertical channel layer passes through the first conductive layers, and a plurality of second conductive layers formed between the pipe channel layer and the source line, wherein the second vertical layer passes through the second conductive layers.

Abstract: An embodiment of a vertical-conduction integrated electronic device formed in a body of semiconductor material which includes: a substrate made of a first semiconductor material and with a first type of conductivity, the first semiconductor material having a first bandgap; an epitaxial region made of the first semiconductor material and with the first type of conductivity, which overlies the substrate and defines a first surface; and a first epitaxial layer made of a second semiconductor material, which overlies the first surface and is in direct contact with the epitaxial region, the second semiconductor material having a second bandgap narrower than the first bandgap. The body moreover includes a deep region of a second type of conductivity, extending underneath the first surface and within the epitaxial region.

Abstract: A gate of a trench type MOSFET device and a method of forming a gate. A gate of a trench type MOSFET device may include a gate oxide film formed on and/or over a trench type gate poly such that parasitic capacitance may be produced in a gate poly. An electric field may be substantially uniformly formed in a MESA region surrounding a gate poly. An overcurrent may be substantially prevented from flowing into a MOS channel around a gate. A gate oxide film may be substantially prevented from being destroyed and/or leakage may be substantially prevented. Reliability of a device may be maximized.

Abstract: A semiconductor device and a method for forming the same are disclosed. The semiconductor device includes a semiconductor substrate including an active region defined by a device isolation film, a trench formed in the device isolation film and the active region, a gate electrode formed at the bottom of the trench, and a high dielectric material layer formed not only over the top of the gate electrode but also over a surface of the trench. As a result, although the gate electrode does not overlap with the junction region, the semiconductor device prevents channel resistance from being increased, resulting in an increase in semiconductor device characteristics.

Abstract: A semiconductor device includes a first-conductivity-type semiconductor layer, a base region of a second-conductivity-type formed in an upper portion of the first-conductivity-type semiconductor layer, first though third trenches penetrating through the base region and reaching to the first-conductivity-type semiconductor layer, the first through third trenches being linked to one another, a source interconnect layer buried in the first through third trenches, the source interconnect layer including a protruding portion, a gate electrode buried in the first trench and the third trench, and formed over the source interconnect layer, a source metal contacting the protruding portion of the source interconnect layer, and a gate metal contacting the gate electrode in the third trench. A contact face between the source metal and the protruding portion at the second trench is formed higher than a contact face between the gate metal and the gate electrode at the third trench.

Abstract: Improved MOSFET structures and processes, where multiple polysilicon embedded regions are introduced into the n+ source contact area. A top poly Field Plate is used to shield the electric field from penetrating into the channel, so that a very short channel can be used without jeopardizing the device drain-source leakage current. A bottom poly Field Plate is used to modulate the electric field distribution in the drift region such that a more uniform field distribution can be obtained.

Abstract: A transistor has a cell array with two or more transistor cells, a temperature sensor, which is integrated in the cell array or is adjacent to the cell array, and an isolation structure. The isolation structure isolates the temperature sensor from the cell array, and has an isolation trench, which is arranged between the cell array and the temperature sensor. The distance between the temperature sensor and the active transistor cell that is closest to the temperature sensor corresponds approximately to the pitch between active transistor cells within the cell array.

Abstract: The invention includes a transistor device having a semiconductor substrate with an upper surface. A pair of source/drain regions are formed within the semiconductor substrate and a channel region is formed within the semiconductor substrate and extends generally perpendicularly relative to the upper surface of the semiconductor substrate. A gate is formed within the semiconductor substrate between the pair of the source/drain regions.

Abstract: A semiconductor device and method for fabricating the same is provided. The semiconductor device includes a trench formed in a substrate, a junction region formed in the substrate on both sides of the trench, a first gate insulation layer formed on the surface of the trench, a first buried conductive layer formed over the first gate insulation layer to fill a portion of the trench, a second buried conductive layer formed between the first buried conductive layer and the first gate insulation layer to provide a gap between the first buried conductive layer and the first gate insulation layer, and a second gate insulation layer buried in the gap.

Abstract: A power semiconductor device capable of transmitting gate signals in all directions (e.g., up-/down-ward/right-/left-ward) on a plane and a method of manufacturing the same. The power semiconductor device includes first conductive regions, formed to a predetermined depth in a surface of a conductive low concentration epitaxial layer. The first conductive regions include linear first conductive layers spaced from each other and linear second conductive layers spaced from each other. Second conductive regions are formed to a smaller width and depth than the first and second conductive layers to form channels in the first and second conductive layers. A gate oxide layer formed on a surface of the epitaxial layer defines first windows having a smaller width than the first conductive layers and second windows having a smaller width than the second conductive layers. A gate polysilicon layer is formed on the gate oxide layer.

Abstract: An isolation region (14) is formed between an edge termination region (2) having deep trenches (20,34) and the central region (4). The isolation region includes gate fingers (18) extending from the edge gate trench regions (28) to the gate trenches (6) in the central region (4) to electrically connect the edge gate trench regions to the gate trenches (6) in the central region. The isolation region also includes isolation fingers (22,24) extending from the edge termination region (2) towards the central region (4) and gate between the gate fingers (18) for reducing the breakdown voltage with a RESURF effect.

Abstract: Method for producing an insulation layer between a first electrode and a second electrode in a trench of a semiconductor body, wherein the method comprises the following features: providing a semiconductor body with a trench formed therein, wherein a first electrode is formed in a lower part of the trench, producing an insulation layer on the first electrode and at the sidewalls of the trench in an upper part of the trench in such a way that the insulation layer is formed in a U-shaped fashion in the trench, producing a protective layer on the insulation layer at least at the bottom of the remaining void in the trench, removing the insulation layer at the sidewalls of the trench in the upper part of the trench, removing the protective layer, producing a second electrode at least on the insulation layer above the first electrode.

Abstract: A method is disclosed for forming a patterned thick metallization atop a semiconductor chip wafer. The method includes fabricating a nearly complete semiconductor chip wafer ready for metallization; depositing a bottom metal layer of sub-thickness TK1 together with its built-in alignment mark using a hot metal process; depositing a top metal layer of sub-thickness TK2 using a cold metal process thus forming a stacked thick metallization of total thickness TK=TK1+TK2; then, use the built-in alignment mark as reference, patterning the stacked thick metallization. A patterned thick metallization is thus formed with the advantages of better metal step coverage owing to the superior step coverage nature of the hot metal process as compared to the cold metal process; and lower alignment error rate owing to the lower alignment signal noise nature of the cold metal process as compared to the hot metal process.

Abstract: Disclosed are semiconductor devices and methods of making semiconductor devices. An exemplary embodiment comprises a semiconductor layer of a first conductivity type having a first surface, a second surface, and a graded net doping concentration of the first conductivity type within a portion of the semiconductor layer. The graded portion is located adjacent to the top surface of the semiconductor layer, and the graded net doping concentration therein decreasing in value with distance from the top surface of the semiconductor layer. The exemplary device also comprises an electrode disposed at the first surface of the semiconductor layer and adjacent to the graded portion.

Abstract: A semiconductor power device comprising a plurality of trench MOSFETs integrated with Schottky rectifier in same cell is disclosed. The invented semiconductor power device comprises a tilt-angle implanted drift region having higher doping concentration than epitaxial layer to reduce Vf in Schottky rectifier portion and to reduce Rds in trench MOSFET portion while maintaining a higher breakdown voltage by implementation of thick gate oxide in trench bottom of trenched gates. Furthermore, the invented semiconductor power device further comprises a Schottky barrier height enhancement region to enhance the barrier layer covered in trench bottom of trenched source-body-Schottky contact in Schottky rectifier portion.

Abstract: Disclosed herein is a semiconductor device including: a first conductivity type semiconductor base body; a first conductivity type pillar region; second conductivity type pillar regions; element and termination regions provided in the first and second conductivity type pillar regions, transistors being formed in the element region, and no transistors being formed in the termination region; body regions; a gate insulating film; gate electrodes; source regions; and body potential extraction regions, wherein voids are formed in the second conductivity type pillar regions of the termination region.

Abstract: A bottom source power metal-oxide-semiconductor field-effect transistor (MOSFET) device includes a gate electrode and a source electrode formed on an initial insulation layer on a first surface of a semiconductor chip and a drain electrode formed on a second surface of the semiconductor chip. The source electrode includes a source metal, a source electrode bump formed on the source metal and a source electrode metal layer on top of the source electrode bump. A first insulation layer covers the gate electrode. A through via aligned to the gate electrode is formed from the second surface of the chip to expose a portion of the gate electrode from the second surface.

Abstract: Improved highly reliable power RFP structures and fabrication and operation processes. The structure includes plurality of localized dopant concentrated zones beneath the trenches of RFPs, either floating or extending and merging with the body layer of the MOSFET or connecting with the source layer through a region of vertical doped region. This local dopant zone decreases the minority carrier injection efficiency of the body diode of the device and alters the electric field distribution during the body diode reverse recovery.

Abstract: A trench MOSFET comprising source regions having a doping profile of a Gaussian-distribution along the top surface of epitaxial layer and floating dummy cells formed between edge trench and active area is disclosed. A SBR of n region existing at cell corners renders the parasitic bipolar transistor difficult to turn on, and the floating dummy cells having no parasitic bipolar transistor act as buffer cells to absorb avalanche energy when gate bias is increasing for turning on channel, therefore, the UIS failure issue is avoided and the avalanche capability of the trench MOSFET is enhanced.

Abstract: A recessed access device having a gate electrode formed of two or more gate materials having different work functions may reduce the gate-induced drain leakage current losses from the recessed access device. The gate electrode may include a first gate material having a high work function disposed in a bottom portion of the recessed access device and a second gate material having a lower work function disposed over the first gate material and in an upper portion of the recessed access device.

Abstract: A low voltage tunnel field effect transistor includes a p-n tunnel junction, a gate-dielectric, a gate, a source-contact, and a drain-contact. The p-n tunnel junction includes a depletion region interfacing together a source-layer and a drain-layer. The depletion region includes a source-tunneling-region of the source-layer and a drain-tunneling-region of the drain-layer. When no external electric field is imposed, the depletion region of the p-n tunnel junction has an internal electric field that substantially points towards the source-tunneling-region and the drain-tunneling-region. The gate-dielectric is interfaced directly onto the drain-tunneling-region such that the drain-tunneling-region is between the source-tunneling-region and the gate-dielectric. The gate is interfaced onto the gate-dielectric such that the gate is configured to impose an external electric field which is oriented substantially in parallel to the internal electric field of the depletion region.

Abstract: A semiconductor device includes a first island and a first electrode. The first island includes a first semiconductor region, a first insulation region, and a first insulating film. The first semiconductor region has first and second side surfaces adjacent to the first insulation region and the first insulating film, respectively. The first electrode is adjacent to the first insulation region and the first insulating film. The first insulating film is between the first electrode and the first semiconductor region.

Abstract: A semiconductor device has a semiconductor substrate having a surface layer and a p-type semiconductor region, wherein the surface layer includes a contact region, a channel region and a drift region, the channel region is adjacent to and in contact with the contact region, the drift region is adjacent to and in contact with the channel region and includes n-type impurities at least in part, and the p-type semiconductor region is in contact with the drift region and at least a portion of a rear surface of the channel region, a main electrode disposed on the surface layer and electrically connected to the contact region, a gate electrode disposed on the surface layer and extending from above a portion of the contact region to above at least a portion of the drift region via above the channel region, and an insulating layer covering at least the portion of the contact region and not covering at least the portion of the drift region.