Abstract: A method for manufacturing semiconductor devices includes providing a substrate having a first region and a second region defined thereon, and a shallow trench isolation (STI) formed in between the first region and the second region, the first region comprising a first gate structure and the second region comprising a second gate structure respectively formed therein; forming a patterned protecting layer covering at least the entire STI and the second region on the substrate; forming recesses not exposing the STI in the substrate respectively at two sides of the first gate structure; and forming an epitaxial layer in the recesses respectively, the epitaxial layer filling up the recesses.

Abstract: An integrated circuit includes a transistor and a capacitor. The transistor includes a first semiconductor layer and a gate stack located on the first semiconductor layer. The gate stack includes a metal layer and a first high-k dielectric layer. A gate spacer is located on sidewalls of the gate stack. The first high-k dielectric layer is located between the first semiconductor layer and the metal layer and between the gate spacer and sidewalls of the metal layer. A first silicide region is located on a first source/drain region. A second silicide region is located on a second source/drain region. The capacitor includes a first terminal that comprises a third silicide region located on a portion of the second semiconductor. A second high-k dielectric layer is located on the silicide region. A second terminal comprises a metal layer that is located on the second high-k dielectric layer.

Abstract: A non-volatile semiconductor memory device comprises a semiconductor substrate and a plurality of gate structures formed on a cell region of the semiconductor substrate. The plurality of gate structures include a first select-gate and a second select-gate disposed on the cell region, the first select-gate and the second select-gate spaced apart from each other. A plurality of cell gate structures are disposed between the first select-gate and the second select-gate. The first select-gate and an adjacent cell gate structure have no air gap defined therebetween. At least a pair of adjacent cell gate structures have an air gap defined therebetween.

Abstract: A semiconductor device having an MOSFET serving as an element to be protected, and an electrostatic protection MOSFET element mounted on the same substrate is produced with the small number of steps while implementing a high protection ability. Low concentration regions and gate electrodes are formed and then an insulation film is formed on a whole surface. Then, etching is performed using a resist pattern as a mask to leave the insulation film in a region from a part of the gate electrode to a part of the low concentration region in each of regions A1 and A3, and on a side wall of the gate electrode in a region A2. Then, a high concentration ion implantation is performed using the gate electrodes and the insulation films as masks, and then a silicide layer is formed.

Abstract: Semiconductor devices using a group III-V material, and methods of manufacturing the same, include a substrate having a groove, a group III-V material layer filling in the groove and having a height the same as a height of the substrate, a first semiconductor device on the group III-V material layer, and a second semiconductor device on the substrate near the groove. The group III-V material layer is spaced apart from inner side surfaces of the groove.

Abstract: A method for fabricating semiconductor device is disclosed. The method includes the steps of: providing a substrate having a transistor region and a resistor region; forming a shallow trench isolation (STI) on the substrate of the resistor region; forming a tank in the STI of the resistor region; and forming a resistor in the tank and on the surface of the STI adjacent to two sides of the tank.

Abstract: A transistor includes a first fin structure and at least a second fin structure formed on a substrate. A deep trench area is formed between the first and second fin structures. The deep trench area extends through an insulator layer of the substrate and a semiconductor layer of the substrate. A high-k metal gate is formed within the deep trench area. A polysilicon layer is formed within the deep trench area adjacent to the metal layer. The polysilicon layer and the high-k metal layer are recessed below a top surface of the insulator layer. A poly strap in the deep trench area is formed on top of the high-k metal gate and the polysilicon material. The poly strap is dimensioned to be below a top surface of the first and second fin structures. The first fin structure and the second fin structure are electrically coupled to the poly strap.

Abstract: Provided is a method of forming a semiconductor device. The method includes forming an insulating film on a semiconductor substrate, a conductive film on the insulating film, and a first structure and a second structure on the conductive film. The semiconductor substrate has first and second regions. The first and second structures are formed on the first and second regions, respectively. An impurity diffused region is formed in the semiconductor substrate using the first structure as a mask. The impurity diffused region overlaps the first structure. A portion of the first structure, and the conductive film are etched to respectively form a gate structure and a capacitor structure on the first and second regions.

Abstract: A semiconductor device comprises a metal gate electrode, a passive device and a hard mask layer. The passive device has a poly-silicon element layer. The hard mask layer is disposed on the metal gate electrode and the passive electrode and has a first opening and a second opening substantially coplanar with each other, wherein the metal gate electrode and the poly-silicon element layer are respectively exposed via the first opening and the second opening; and there is a distance between the first opening and the metal gate electrode substantially less than the distance between the second opening and the poly-silicon element layer.

Abstract: When forming sophisticated high-k metal gate electrode structures in an early manufacturing stage, superior process robustness, reduced yield loss and an enhanced degree of flexibility in designing the overall process flow may be accomplished by forming and patterning the sensitive gate materials prior to forming isolation regions.

Abstract: A semiconductor device includes a semiconductor substrate having a first portion and a second portion and a first transistor of a first type formed in the first portion of the substrate, the first transistor being operable at a first voltage, and the first transistor including a doped channel region of a second type opposite of the first type. The semiconductor device also includes a second transistor of the second type formed in the second portion of the substrate, the second transistor being operable at a second voltage greater than the first voltage, the second transistor including an extended doped feature of the second type. Further, the semiconductor device includes a well of the first type in the semiconductor substrate under a gate of the second transistor, wherein the well does not extend directly under the extended doped feature and the extended doped feature does not extend directly under the well.

Abstract: Electronic devices (20, 20?) of superior design flexibility that avoid channel-width quantization effects common with prior art fin-type (FIN) field effect transistors (FIN-FETS) (22) are obtained by providing multiple FIN-FETs (22) and at least one planar FET (32, 32?) on a common substrate (21), wherein the multiple FIN-FETs (22) have fins (231, 232) of at least fin heights H1 and H2, with H2<H1. The multiple FIN-FETs (22) and the at least one planar FET (32, 32?) are separated vertically as well as laterally, which aids electrical isolation therebetween. Such electrical isolation can be enhanced by forming the planar FET (32) in a semiconductor region (441) insulated from the common substrate (21).

Abstract: To provide a semiconductor device and a method of manufacturing the same capable of suppressing, when a plurality of MIS transistors having different absolute values of threshold voltage is used, the reduction of the drive current of a MIS transistor having a greater absolute value of threshold voltage. The threshold voltage of a second nMIS transistor is greater than the threshold voltage of a first nMIS transistor and the sum of the concentration of lanthanum atom and the concentration of magnesium atom in a second nMIS high-k film included in the second nMIS transistor is lower than the sum of the concentration of lanthanum atom and the concentration of magnesium atom in a first nMIS high-k film included in the first nMIS transistor.

Abstract: A method is provided for fabricating a microelectronic device and a resistor on a substrate. The method can include forming device regions in a monocrystalline semiconductor region of a substrate, in which the device regions have edges defined according to a first semiconductor feature overlying a major surface of the semiconductor region. A dielectric region is formed having a planarized surface overlying the semiconductor region and overlying a second semiconductor feature disposed above a surface of an isolation region in the substrate. The surface of the isolation region can be disposed below the major surface. The method can further include removing at least a portion of the first semiconductor feature exposed at the planarized surface of the dielectric region to form an opening and forming a gate at least partially within the opening.

Abstract: The present disclosure provides manufacturing techniques in which sophisticated high-k metal gate electrode structures may be formed in an early manufacturing stage on the basis of a selectively applied threshold voltage adjusting semiconductor alloy. In order to reduce the surface topography upon patterning the deposition mask while still allowing the usage of well-established epitaxial growth recipes developed for silicon dioxide-based hard mask materials, a silicon nitride base material may be used in combination with a surface treatment. In this manner, the surface of the silicon nitride material may exhibit a silicon dioxide-like behavior, while the patterning of the hard mask may be accomplished on the basis of highly selective etch techniques.

Abstract: Example embodiments provide a transistor and a method of manufacturing the same. The transistor may include a channel layer formed of an oxide semiconductor and a gate having a three-dimensional structure. A plurality of the transistors may be stacked in a perpendicular direction to a substrate. At least some of the plurality of transistors may be connected to each other.

Abstract: An integrated circuit ESD protection circuit (270) is formed with a combination device consisting of a gated diode (271) and an output buffer MOSFET (272) where the body tie fingers of a first conductivity type (307) are formed in the substrate (301, 302) and isolated from the drain regions of a second conductivity type (310) using a plurality of diode poly fingers (231, 232) which are interleaved with a plurality of poly gate fingers (204, 205) forming the output buffer MOSFET (272).

Abstract: A polysilicon film to be a resistor element is formed on a resistor element formation region of a semiconductor substrate while a polysilicon gate and high concentration impurity regions are formed on a transistor formation region. Thereafter, an insulating film is formed on the entire surface of the semiconductor substrate. Then, a photoresist film is formed to cover the transistor formation region, and a conductive impurity is ion-implanted into the polysilicon film. Next, the photoresist film is removed by ashing.

Abstract: Embodiments relate to an improved tri-gate device having gate metal fills, providing compressive or tensile stress upon at least a portion of the tri-gate transistor, thereby increasing the carrier mobility and operating frequency. Embodiments also contemplate method for use of the improved tri-gate device.

Abstract: A nonvolatile memory device comprises a semiconductor substrate comprising alternating, parallel active regions and isolation regions; first and second selection lines intersecting the active regions and the isolation regions; first junctions formed in the active regions between the first and second selection lines; spacers formed on sidewalls of the first and second selection lines; second junctions deeper than the first junctions formed in the first junctions, respectively; contact plugs coupled to one side of the respective second junctions; and dummy plugs coupled second sides of the respective second junctions.

Abstract: Transistor devices having vertically stacked carbon nanotube channels and techniques for the fabrication thereof are provided. In one aspect, a transistor device is provided. The transistor device includes a substrate; a bottom gate embedded in the substrate with a top surface of the bottom gate being substantially coplanar with a surface of the substrate; a stack of device layers on the substrate over the bottom gate, wherein each of the device layers in the stack includes a first dielectric, a carbon nanotube channel on the first dielectric, a second dielectric on the carbon nanotube channel and a top gate on the second dielectric; and source and drain contacts that interconnect the carbon nanotube channels in parallel. A method of fabricating a transistor device is also provided.

Abstract: A semiconductor device with a dynamic gate drain capacitance. One embodiment provides a semiconductor device. The device includes a semiconductor substrate, a field effect transistor structure including a source region, a first body region, a drain region, a gate electrode structure and a gate insulating layer. The gate insulating layer is arranged between the gate electrode structure and the body region. The gate electrode structure and the drain region partially form a capacitor structure including a gate-drain capacitance configured to dynamically change with varying reverse voltages applied between the source and drain regions. The gate-drain capacitance includes at least one local maximum at a given threshold or a plateau-like course at given reverse voltage.

Abstract: A fabricating method of a pixel structure is provided. A substrate has an array of pixel areas. The common electrode wire is positioned only in a portion of the pixel area. A first capacitance storage electrode is formed in each of the pixel areas and electrically connected between two adjacent common electrode wires. A gate insulation layer covers the scan line, the gate electrode, the common electrode wire and the first capacitance storage electrode. A semiconductor layer is formed on the gate insulation layer above the gate electrode. The source and the drain is formed on two sides of the semiconductor layer. A passivation layer is formed on the substrate to cover the data line, the source and the drain. A pixel electrode is formed in each of the pixel areas, and the pixel electrode is electrically connected with the drain through the contact window.

Abstract: A semiconductor device including a substrate, a first device, a second device and an interlayer dielectric layer is provided. The substrate has a first area and a second area. The first device is disposed in the first area of the substrate and includes a first dielectric layer on the substrate and a metal gate on the first dielectric layer. The second device is in the second area of the substrate and includes a second dielectric layer on the substrate and, a polysilicon layer on the second dielectric layer. It is noted that the height of the polysilicon layer is less than that of the metal gate of the first device. The interlayer dielectric layer covers the second device.

Abstract: In MOS transistor elements, a strain-inducing semiconductor alloy may be embedded in the active region with a reduced offset from the channel region by applying a spacer structure of reduced width. In order to reduce the probability of creating semiconductor residues at the top area of the gate electrode structure, a certain degree of corner rounding of the semiconductor material may be introduced, which may be accomplished by ion implantation prior to epitaxially growing the strain-inducing semiconductor material. This concept may be advantageously combined with the provision of sophisticated high-k metal gate electrodes that are provided in an early manufacturing stage.

Abstract: The invention provides a method for forming thin film transistors including a polycrystalline semiconducting film. The method comprises depositing a first layer of amorphous semiconducting thin film on to a substrate; depositing a second layer of thin film on to the first layer of amorphous semiconducting thin film; patterning the second layer of thin film so that the first layer of amorphous semiconducting thin film is exposed at selected locations; exposing the first and second layers of thin film to a nickel containing compound in either a solution or a vapor phase ; removing the second layer of thin film; and annealing the first layer of amorphous semiconducting thin film at an elevated temperature so the first layer of amorphous semiconducting thin film converts into a polycrystalline semiconducting thin film.

Abstract: A memory device includes a substrate, a plurality of wordlines arranged over the substrate, a plurality of pillars formed over the substrate between the wordlines, a gate electrode surrounding external walls of the pillars to be connected to the wordlines, and an insulation layer for insulating one sidewall of each wordline from the gate electrode.

Abstract: A method includes forming a transistor at a surface of a semiconductor substrate, wherein the step of forming the transistor comprises forming a gate electrode, and forming a source/drain region adjacent the gate electrode. First metal features are formed to include at least portions at a same level as the gate electrode. Second metal features are formed simultaneously, and are over and contacting the first metal features. A first one of the second metal features is removed and replaced with a third metal feature, wherein a second one of the second metal features is not removed. A fourth metal feature is formed directly over and contacting the gate electrode, wherein the third and the fourth metal features are formed using a same metal-filling process.

Abstract: A semiconductor chip comprising a capacitor capable of effectively controlling the voltage drop of an LSI is provided. A semiconductor substrate is provided with an element electrode having at least its surface constituted of an aluminum electrode. The surface of the aluminum electrode is roughened. An oxide film is provided on the aluminum electrode. A conductive film is provided on the oxide film. The aluminum electrode, oxide film and conductive film form a capacitor.

Abstract: An integrated circuit containing logic transistors and an array of SRAM cells in which the logic transistors are formed in semiconductor material with one crystal orientation and the SRAM cells are formed in a second semiconductor layer with another crystal orientation. A process of forming an integrated circuit containing logic transistors and an array of SRAM cells in which the logic transistors are formed in a top semiconductor layer with one crystal orientation and the SRAM cells are formed in an epitaxial semiconductor layer with another crystal orientation. A process of forming an integrated circuit containing logic transistors and an array of SRAM cells in which the SRAM cells are formed in a top semiconductor layer with one crystal orientation and the logic transistors are formed in an epitaxial semiconductor layer with another crystal orientation.

Abstract: An apparatus and method is described for measuring a local surface temperature of a semiconductor device under stress. The apparatus includes a substrate, and a reference MOSFET. The reference MOSFET may be disposed closely adjacent to the semiconductor device under stress. A local surface temperature of the semiconductor device under stress may be measured using the reference MOSFET, which is not under stress. The local surface temperature of the semiconductor device under stress may be determined as a function of drain current values of the reference MOSFET measured before applying stress to the semiconductor device and while the semiconductor device is under stress.

Abstract: A method for improving the reverse breakdown voltage between P-well and N-well and related semiconductor silicon devices are described herein. In one aspect, a semiconductor silicon device comprises a substrate; a P-well in said substrate; an N-well in said substrate; wherein said N-well and said P-well are separated by said substrate. In another aspect, a method for increasing the reverse breakdown voltage from P-well to N-well comprises: providing a substrate; forming an N-well and a P-well in said substrate and separating said N-well and said P-well by said substrate.

Abstract: An integrated structure combines field effect transistors and a Schottky diode. Trenches formed into a substrate composition extend along a depth of the substrate composition forming mesas therebetween. Each trench is filled with conductive material separated from the trench walls by dielectric material forming a gate region. Two first conductivity type body regions inside each mesa form wells partly into the depth of the substrate composition. An exposed portion of the substrate composition separates the body regions. Second conductivity type source regions inside each body region are adjacent to and on opposite sides of each well. Schottky barrier metal inside each well forms Schottky junctions at interfaces with exposed vertical sidewalls of the exposed portion of the substrate composition separating the body regions.

Abstract: A method of manufacturing a nonvolatile memory device wherein first gate lines and second gate lines are formed over a semiconductor substrate. The first gate lines are spaced-from each other at a first width, the second gate lines are spaced-from each other at a second width, and the first width is wider than the second width. A first ion implantation process of forming first junction regions in the semiconductor substrate between the first gate lines and the second gate lines is performed. A second ion implantation process of forming second junction regions in the respective first junction regions between the first gate lines is then performed.

Abstract: A semiconductor device with a dynamic gate drain capacitance. One embodiment provides a semiconductor device. The device includes a semiconductor substrate, a field effect transistor structure including a source region, a first body region, a drain region, a gate electrode structure and a gate insulating layer. The gate insulating layer is arranged between the gate electrode structure and the body region. The gate electrode structure and the drain region partially form a capacitor structure including a gate-drain capacitance configured to dynamically change with varying reverse voltages applied between the source and drain regions. The gate-drain capacitance includes at least one local maximum at a given threshold or a plateau-like course at given reverse voltage.

Abstract: There are provided a method of manufacturing a semiconductor device which achieves a reduction in implantation masks, and such a semiconductor device. By implanting boron into NMOS regions using a resist mask and another resist mask as the implantation masks, p-type impurity regions serving as the halo regions of access transistors and drive transistors are formed. By further implanting phosphorus or arsenic into a PMOS region using another resist mask as the implantation mask, n-type impurity regions serving as the halo regions of load transistors are formed.

Abstract: A method for producing a semiconductor device includes a step of forming a conductor layer and a first semiconductor layer containing a donor impurity or an acceptor impurity on a first semiconductor substrate; a step of forming a second insulating layer so as to cover the first semiconductor layer; a step of thinning the first semiconductor substrate to a predetermined thickness; a step of forming, from the first semiconductor substrate, a pillar-shaped semiconductor having a pillar-shaped structure on the first semiconductor layer; a step of forming a first semiconductor region in the pillar-shaped semiconductor by diffusing the impurity from the first semiconductor layer; and a step of forming a pixel of a solid-state imaging device with the pillar-shaped semiconductor into which the impurity has been diffused.

Abstract: A method of forming an integrated circuit includes forming at least one transistor over a substrate. The at least one transistor includes a first gate dielectric structure disposed over a substrate. A work-function metallic layer is disposed over the first gate dielectric structure. A conductive layer is disposed over the work-function metallic layer. A source/drain (S/D) region is disposed adjacent to each sidewall of the first gate dielectric structure. At least one resistor structure is formed over the substrate. The at least one resistor structure includes a first doped semiconductor layer disposed over the substrate. The at least one resistor structure does not include any work-function metallic layer between the first doped semiconductor layer and the substrate.

Abstract: An integrated method includes fabricating a metal gate transistor and a polysilicon resistor structure. A photoresistor layer is defined by an SAB photo mask and covers a part of a high resistance structure of the polysilicon resistor. When the dummy gate of the transistor is etched, the part of the high resistance structure is protected by the patterned photoresistor layer. The polysilicon resistor is formed simultaneously with the transistor. Furthermore, the polysilicon resistor still has sufficient resistance and includes two metal structures for electrical connection.

Abstract: A method of fabricating a semiconductor device is provided that includes providing a semiconductor substrate having a first portion and a second portion, forming a first transistor in the first portion of the substrate, the first transistor being operable at a first voltage, and forming a second transistor in the second portion of the substrate, the second transistor being operable at a second voltage greater than the first voltage. The formation of the second transistor includes forming an extended feature of the second transistor with a photomask that is used to adjust a threshold voltage of the first transistor.

Abstract: Disclosed is an integrated circuit device having series-connected planar or non-planar field effect transistors (FETs) with integrated voltage equalization and a method of forming the device. The series-connected FETs comprise gates positioned along a semiconductor body to define the channel regions for the series-connected FETs. Source/drain regions are located within the semiconductor body on opposing sides of the channel regions such that each portion of the semiconductor body between adjacent gates comprises one source/drain region for one field effect transistor abutting another source/drain region for another field effect transistor. Integrated voltage equalization is achieved through a conformal conductive layer having a desired resistance and positioned over the series-connected FETs such that it is electrically isolated from the gates, but in contact with the source/drain regions within the semiconductor body.

Abstract: A power semiconductor device with an electrostatic discharge (ESD) structure includes an N-type semiconductor substrate, at least one ESD device, and at least one trench type transistor device. The N-type semiconductor has at least two trenches, and the ESD device is disposed in the N-type semiconductor substrate between the trenches. The ESD device includes a P-type first doped region, and an N-type second doped region and an N-type third doped region disposed in the P-type first doped region. The N-type second doped region is electrically connected to a gate of the trench type transistor device, and the N-type third doped region is electrically connected to a drain of the trench type transistor device.

Abstract: A thin-film transistor (TFT) array substrate comprises: a substrate; an active layer and a capacitor first electrode formed on the substrate; a gate insulating film formed on the substrate, the active layer and the capacitor first electrode; a gate electrode formed on the gate insulating film corresponding to the active layer and a capacitor second electrode formed on the gate insulating film corresponding to the capacitor first electrode; an interlayer insulating film formed on the gate insulating film, the gate electrode, and the capacitor second electrode; and a pixel electrode, a source electrode, and a drain electrode formed on the interlayer insulating film; wherein at least one of the source electrode and the drain electrode is formed on the pixel electrode. A method of fabricating the TFT array substrate is also disclosed.

Abstract: A thin film transistor substrate, a display apparatus using the same and a manufacturing method thereof are provided. The display apparatus includes a thin film transistor substrate, a top substrate and a display medium layer. The thin film transistor substrate includes a composite plate and several thin film transistors. The composite plate includes a core material structure and two insulation structures. The core material structure includes a metal layer. The two insulation structures are respectively disposed at two sides of the core material structure so as to sandwich the core material structure therebetween. The thin film transistors are disposed on the composite plate. The display medium layer is disposed between the thin film transistor substrate and the top substrate.

Abstract: A semiconductor structure including a substrate, at least one power MOSFET, a floating diode or a body diode, and at least one Schottky diode is provided. The substrate has a first area, a second area and a third area. The second area is between the first area and the third area. The at least one power MOSFET is in the first area. The floating diode or the body diode is in the second area. The at least one Schottky diode is in the third area. Further, the contact plugs of the power MOSFET and the Schottky diode include tungsten and are electronically connected to each other.

Abstract: A monolithically-integrated dual surge protective device and its fabrication method are disclosed. The exemplary dual surge protective device includes a LDMOS device and a diode assembly which is consisted. of multiple diodes series-wound on back-to-back basis and whose one end is connected to drain electrode of the LDMOS device and the other-end is connected to gate electrode of the LDMOS device. The diode assembly can be fabricated directly in the gate electrode area of the LDMOS device after fabrication of the LDMOS device is completed. The protective device is equivalent to combination of diodes and LDMOS in respect to operating principles and structures, with the advantage of enhanced effect of surge prevention and cost reduction of surge device as it can be integrated into a chip.

Abstract: A three terminal bi-directional laterally diffused metal oxide semiconductor (LDMOS) transistor which includes two uni-directional LDMOS transistors in series sharing a common drain node, and configured such that source nodes of the uni-directional LDMOS transistors serve as source and drain terminals of the bi-directional LDMOS transistor. The source is shorted to the backgate of each LDMOS transistor. The gate node of each LDMOS transistor is clamped to its respective source node to prevent source-gate breakdown, and the gate terminal of the bi-directional LDMOS transistor is connected to the gate nodes of the constituent uni-directional LDMOS transistors through blocking diodes. The common drain is a deep n-well which isolates the two p-type backgate regions. The gate node clamp can be a pair of back-to-back zener diodes, or a pair of self biased MOS transistors connected source-to-source in series.

Abstract: The present technology discloses a semiconductor die integrating a MOSFET device and a Schottky diode. The semiconductor die comprises a MOSFET area comprising the active region of MOSFET, a Schottky diode area comprising the active region of Schottky diode, and a termination area comprising termination structures. Wherein the Schottky diode area is placed between the MOSFET area and the termination area such that the Schottky diode area surrounds the MOSFET area.

Abstract: There is disclosed an array substrate which has a base substrate and data lines and gate lines on the base substrate, The data lines and gate lines intersect with each other to define pixel units, and each pixel unit comprises a pixel electrode, a gate electrode, a source electrode, a drain electrode and an active layer, and the pixel electrode, the gate electrode and the gate line adjoin to the base substrate, and the gate electrode is formed of a same material as that for forming the pixel electrode.

Abstract: A semiconductor device in which a reliable high voltage p-channel transistor is formed without an increase in cost and the number of manufacturing steps. The transistor includes: a semiconductor substrate having a main surface and a p-type region therein; a p-type well region located over the p-type region and in the main surface, having a first p-type impurity region to obtain a drain electrode; an n-type well region adjoining the p-type well region along the main surface and having a second p-type impurity region to obtain a source electrode; a gate electrode between the first and second p-type impurity regions along the main surface; and a p-type buried channel overlying the n-type well region and extending along the main surface. The border between the n-type and p-type well regions is nearer to the first p-type impurity region than the gate electrode end near to the first p-type impurity region.