Abstract: Some embodiments include a memory cell string having a body having a channel extending therein and in contact with a source/drain, a select gate adjacent to the body, a plurality of access lines adjacent to the body, and a dielectric in a portion of the body between the source/drain and a level corresponding to an end of the plurality of access lines most adjacent to the select gate. The dielectric in the portion of the body does not extend along an entire length of the body. Other embodiments are described and claimed.

Abstract: A nonvolatile memory device includes a substrate, a structure including a stack of alternately disposed layers of conductive and insulation materials disposed on the substrate, a plurality of pillars extending through the structure in a direction perpendicular to the substrate and into contact with the substrate, and information storage films interposed between the layers of conductive material and the pillars. In one embodiment, upper portions of the pillars located at the same level as an upper layer of the conductive material have structures that are different from lower portions of the pillars. In another embodiment, or in addition, upper string selection transistors constituted by portions of the pillars at the level of an upper layer of the conductive material are programmed differently from lower string selection transistors.

Abstract: A vertical semiconductor device includes a first active pillar vertically protruded from a semiconductor substrate; a first vertical gate connected to at least one side of the first active pillar and formed along a direction that crosses a buried bit line; and a first body line connected to at least one side of the first active pillar which is not connected to the first vertical gate.

Abstract: Among other things, one or more techniques for forming a vertical tunnel field effect transistor (FET), and a resulting vertical tunnel FET are provided herein. In an embodiment, the vertical tunnel FET is formed by forming a core over a first type substrate region, forming a second type channel shell around a circumference greater than a core circumference, forming a gate dielectric around a circumference greater than the core circumference, forming a gate electrode around a circumference greater than the core circumference, and forming a second type region over a portion of the second type channel shell, where the second type has a doping opposite a doping of the first type. In this manner, line tunneling is enabled, thus providing enhanced tunneling efficiency for a vertical tunnel FET.

Abstract: A trench MOS structure is disclosed. The trench MOS structure includes a substrate, an epitaxial layer, a doping well, a doping region and a trench gate. The substrate has a first conductivity type, a first side and a second side opposite to the first side. The epitaxial layer has the first conductivity type and is disposed on the first side. The doping well has a second conductivity type and is disposed on the epitaxial layer. The doping region has the first conductivity type and is disposed on the doping well. The trench gate is partially disposed in the doping region. The trench gate has a bottle shaped profile with a top section smaller than a bottom section, both are partially disposed in the doping well. The bottom section of two adjacent trench gates results in a higher electrical field around the trench MOS structures.

Abstract: A method for fabricating a non-volatile memory device includes forming a stacked structure where a plurality of inter-layer dielectric layers and a plurality of second sacrificial layers are alternately stacked over a substrate, forming a channel layer that is coupled with a portion of the substrate by penetrating through the stacked structure, forming a slit that penetrates through the second sacrificial layers by selectively etching the stacked structure, removing the second sacrificial layers that are exposed through the slit, forming an epitaxial layer over the channel layer exposed as a result of the removal of the second sacrificial layers, and forming a gate electrode layer filling a space from which the second sacrificial layers are removed, and a memory layer interposed between the gate electrode layer and the epitaxial layer.

Abstract: A gate stack including a gate dielectric and a gate electrode is formed over at least one compound semiconductor fin provided on an insulating substrate. The at least one compound semiconductor fin is thinned employing the gate stack as an etch mask. Source/drain extension regions are epitaxially deposited on physically exposed surfaces of the at least one semiconductor fin. A gate spacer is formed around the gate stack. A raised source region and a raised drain region are epitaxially formed on the source/drain extension regions. The source/drain extension regions are self-aligned to sidewalls of the gate stack, and thus ensure a sufficient overlap with the gate electrode. Further, the combination of the source/drain extension regions and the raised source/drain regions provides a low-resistance path to the channel of the field effect transistor.

Abstract: A semiconductor device and fabrication methods are disclosed. The device includes a plurality of gate electrodes formed in trenches located in an active region of a semiconductor substrate. A first gate runner is formed in the substrate and electrically connected to the gate electrodes, wherein the first gate runner surrounds the active region. A second gate runner is connected to the first gate runner and located between the active region and a termination region. A termination structure surrounds the first and second gate runners and the active region. The termination structure includes a conductive material in an insulator-lined trench in the substrate, wherein the termination structure is electrically shorted to a source or body layer of the substrate thereby forming a channel stop for the device.

Abstract: A semiconductor device includes semiconductor bodies formed substantially perpendicular to a semiconductor substrate, buried bit lines formed in the semiconductor bodies and including a metal silicide; and barrier layers formed under and over the buried bit lines and containing germanium.

Abstract: The invention prevents a semiconductor device from warping due to heat when it is used. The invention also prevents a formation defect such as peeling of a resist layer used as a plating mask and a formation defect of a front surface electrode. A source pad electrode connected to a source region is formed on a front surface of a semiconductor substrate forming a vertical MOS transistor. A front surface electrode is formed on the source pad electrode by a plating method using a resist layer having openings as a mask. The semiconductor substrate formed with the front surface electrode is thinned by back-grinding. A back surface electrode connected to a drain region is formed on the back surface of the semiconductor substrate. The front surface electrode and the back surface electrode are made of metals having the same coefficients of linear expansion, preferably copper. The front surface electrode and the back surface electrode preferably have the same thicknesses or almost the same thicknesses.

Abstract: A semiconductor device including a buried cell array transistor and an electronic device including the same are provided. The device includes a field region in a substrate and the filed region defines an active region. A first source/drain region and a second source/drain region are in the active region. A gate trench is between the first and second source/drain regions, and in the active region and the field region. A gate structure is within the gate trench. The gate structure includes a gate electrode, an insulating gate capping pattern on the gate electrode, a gate dielectric between the gate electrode and the active region, and an insulating metal-containing material layer between the insulating gate capping pattern and the active region.

Abstract: The object of the invention is to provide a semiconductor device realizing high-speed operation of surrounding gate transistors (SGTs), which are three-dimensional semiconductors, by increasing the ON current of the SGTs. This object is achieved by a semiconductor element being provided in which a source, a drain and a gate are positioned in layers on a substrate, the semiconductor element being provided with: a silicon column; an insulating body surrounding the side surface of the silicon column; a gate surrounding the insulating body; a source region positioned above or below the silicon column; and a drain region positioned below or above the silicon column; wherein the contact surface of the silicon column with the source region is smaller than the contact surface of the silicon column with the drain region.

Abstract: A device includes a semiconductor region of a first conductivity type, a trench extending into the semiconductor region, and a conductive field plate in the trench. A first dielectric layer separates a bottom and sidewalls of the field plate from the semiconductor region. A main gate is disposed in the trench and overlapping the field plate. A second dielectric layer is disposed between and separating the main gate and the field plate from each other. A Doped Drain (DD) region of the first conductivity type is under the second dielectric layer, wherein an edge portion of the main gate overlaps the DD region. A body region includes a first portion at a same level as a portion of the main gate, and a second portion at a same level as, and contacting, the DD region, wherein the body region is of a second conductivity type opposite the first conductivity type.

Abstract: A closed cell trenched power semiconductor structure is provided. The closed cell trenched power semiconductor structure has a substrate and cells. The cells are arranged on the substrate in an array. Every cell has a body and a trenched gate. The trenched gate surrounds the body. A side wall of the trenched gate facing body has a concave.

Abstract: This invention discloses a trench MOSFET comprising a top side drain region in a wide trench in a termination area besides a BV sustaining area, wherein said top side drain comprises a top drain metal connected to an epitaxial layer and a substrate through a plurality of trenched drain contacts, wherein the wide trench is formed simultaneously when a plurality of gate trenches are formed in an active area, and the trenched drain contacts are formed simultaneously when a trenched source-body contact is formed in the active area.

Abstract: A semiconductor pillar which has a first conductivity type and protrudes from a semiconductor substrate, is formed. A bottom diffusion layer having a second conductivity type is formed in the semiconductor substrate around a bottom of the semiconductor pillar. A gate insulator film which covers a side surface of the semiconductor pillar, is formed. A gate electrode which covers the gate insulator film, is formed. A top diffusion layer having the second conductivity type is formed at a top portion of the semiconductor pillar. The top diffusion layer including a semiconductor body is formed by an epitaxial growth which contains an impurity.

Abstract: A process for forming a short channel trench MOSFET. The process includes forming a first implant at the bottom of a trench that is formed in the body of the trench MOSFET and forming a second or angled implant that is tilted in its orientation and directed perpendicular to the trench that is formed in the body of the trench MOSFET. The second implant is adjusted so that it does not reach the bottom of the trench. In one embodiment the angled implant is n-type material.

Abstract: According to one embodiment, a semiconductor device includes a semiconductor layer; a plurality of semiconductor regions; second semiconductor region; a first electrode being positioned between the plurality of first semiconductor regions, the first electrode contacting with the semiconductor layer, each of the plurality of first semiconductor regions, and the second semiconductor region via a first insulating film; a second electrode provided below the first electrode, and contacting with the semiconductor layer via a second insulating film; an insulating layer interposed between the first electrode and the second electrode; a third electrode electrically connected to the semiconductor layer; and a fourth electrode connected to the second semiconductor region. The first electrode has a first portion and a pair of second portions. And each of the pair of second portions is provided along the first insulating film.

Abstract: To provide a highly reliable semiconductor device. To provide a semiconductor device which prevents a defect and achieves miniaturization. An oxide semiconductor layer in which the thickness of a region serving as a source region or a drain region is larger than the thickness of a region serving as a channel formation region is formed in contact with an insulating layer including a trench. In a transistor including the oxide semiconductor layer, variation in threshold voltage, degradation of electric characteristics, and shift to normally on can be suppressed and source resistance or drain resistance can be reduced, so that the transistor can have high reliability.

Abstract: A nonvolatile memory device includes a substrate, a channel layer protruding from the substrate, a gate conductive layer surrounding the channel layer, a gate insulating layer disposed between the channel layer and the gate conductive layer, and a first insulating layer spaced apart from the channel layer and disposed on the top and bottom of the gate conductive layer. The gate insulating layer extends between the gate conductive layer and the first insulating layer.

Abstract: A vertical thin film transistor includes a substrate, a first wall, a second wall, a source electrode, a drain electrode, a semiconductor layer, a gate insulating layer, and a gate electrode. The first wall and the second walls are spaced apart from each other on the substrate. The source electrode is formed on a top surface of the first wall. The drain electrode is provided on the substrate between the first and second walls. The semiconductor layer is formed on the source electrode, a sidewall of the first wall, and the drain electrode. The gate insulating layer covers the first and second walls, the source and drain electrodes, and the semiconductor layer. The gate electrode is disposed between the first and second walls in a planar view. The vertical thin film transistor may be formed without a mask.

Abstract: A semiconductor device includes first, second, and third semiconductor layers each having multiple diffusion layers. The first direction widths of the first diffusion layers are the same. The amount of impurity within the first diffusion layers gradually increases from the bottom end towards the top end of the first semiconductor layer. The first direction widths of the second diffusion layers are the same. The amounts of impurity within the second diffusion layers are the same. The first direction widths of the third diffusion layers are narrower than the first direction widths of the first diffusion layers and the first direction widths of the second diffusion layers at the same level, and gradually become narrower from the bottom end towards the top end of the third semiconductor layer. The amount of impurity within the third diffusion layers are the same.

Abstract: A semiconductor structure includes a III-nitride substrate and a drift region coupled to the III-nitride substrate along a growth direction. The semiconductor substrate also includes a channel region coupled to the drift region. The channel region is defined by a channel sidewall disposed substantially along the growth direction. The semiconductor substrate further includes a gate region disposed laterally with respect to the channel region.

Abstract: A method of forming a buried bit line is provided. A substrate is provided and a line-shaped trench region is defined in the substrate. A line-shaped trench is formed in the line-shaped trench region of the substrate. The line-shaped trench includes a sidewall surface and a bottom surface. Then, the bottom surface of the line-shaped trench is widened to form a curved bottom surface. Next, a doping area is formed in the substrate adjacent to the curved bottom surface. Lastly, a buried conductive layer is formed on the doping area such that the doping area and the buried conductive layer together constitute the buried bit line.

Abstract: Provided is a semiconductor device including a substrate having active patterns extending between first trenches and between second trenches (the first and second trenches intersecting each other), and gate patterns disposed within the first trenches, wherein each of the active patterns includes lower and upper impurity regions, and a channel region between the lower and upper impurity regions, the lower and upper impurity regions being vertically spaced apart from each other and having a conductivity type different from the substrate, and the channel region having the same conductivity type as the substrate, and a bottom surface of the gate pattern is closer to a bottom surface of the first trench than the lower impurity region.

Abstract: A transistor structure is formed to include a substrate and, overlying the substrate, a source; a drain; and a channel disposed vertically between the source and the drain. The channel is coupled to a gate conductor that surrounds the channel via a layer of gate dielectric material that surrounds the channel. The gate conductor is composed of a first electrically conductive material having a first work function that surrounds a first portion of a length of the channel and a second electrically conductive material having a second work function that surrounds a second portion of the length of the channel. A method to fabricate the transistor structure is also disclosed. The transistor structure can be characterized as being a vertical field effect transistor having an asymmetric gate.

Abstract: A method for fabricating a semiconductor memory device includes defining an active region having a shape protruding upward by forming a trench in a semiconductor substrate; forming an open region obtained by selectively exposing a lower side portion of the active region while forming a sidewall layer along the shape of the active region; covering the open region with a silicon layer; forming an impurity region in the lower side portion of the active region; forming a barrier metal layer on the silicon layer and the active region; forming a bit line metal layer buried in the entire active region; and forming a buried bit line having the barrier metal layer, the bit line metal layer and a silicide metal layer formed between the silicon layer and the barrier metal layer by etching the bit line metal layer up to a portion at which the impurity region is formed.

Abstract: A metal-oxide-semiconductor transistor (MOS) and method of fabricating the same, in which the effective channel length is increased relative to the width of the gate electrode. A dummy gate electrode overlying dummy gate dielectric material is formed at the surface of the structure, with self-aligned source/drain regions, and dielectric spacers on the sidewalls of the dummy gate structure. The dummy gate dielectric underlies the sidewall spacers. Following removal of the dummy gate electrode and the underlying dummy gate dielectric material, including from under the spacers, a silicon etch is performed to form a recess in the underlying substrate. This etch is self-limiting on the undercut sides, due to the crystal orientation, relative to the etch of the bottom of the recess. The gate dielectric and gate electrode material are then deposited into the remaining void, for example to form a high-k metal gate MOS transistor.

Abstract: A semiconductor device having a gate positioned in a recess between the source region and a drain region that are adjacent either side of the gate electrode. A channel region is below a majority of the source region as well as a majority of the drain region and the entire gate electrode.

Abstract: A semiconductor device includes a first pillar, a second pillar underneath the first pillar, and a third pillar on a top of the first pillar. The second pillar has a second-conductive type region in a surface thereof except at least a part of a contact surface region with the first pillar, and a first-conductive type region therein and surrounded by the second-conductive type region. The third pillar has a second-conductive type region in a surface thereof except at least a part of a contact surface region with the first pillar, and a first-conductive type region therein and surrounded by the second-conductive type region. The first-conductive type region of each of the second pillar and the third pillar has a length greater than that of a depletion layer extending from a base portion of the second-conductive type region of a respective one of the second pillar and the third pillar.

Abstract: An embodiment of a process for manufacturing a power semiconductor device envisages the steps of: providing a body of semiconductor material having a top surface and having a first conductivity; forming columnar regions having a second type of conductivity within the body of semiconductor material, and surface extensions of the columnar regions above the top surface; and forming doped regions having the second type of conductivity, in the proximity of the top surface and in contact with the columnar regions. The doped regions are formed at least partially within the surface extensions of the columnar regions; the surface extensions and the doped regions have a non-planar surface pattern, in particular with a substantially V-shaped groove.

Abstract: A semiconductor device includes a first transistor cell including a first gate electrode in a first trench. The semiconductor device further includes a second transistor cell including a second gate electrode in a second trench, wherein the first and second gate electrodes are electrically connected. The semiconductor device further includes a third trench between the first and second trenches, wherein the third trench extends deeper into a semiconductor body from a first side of the semiconductor body than the first and second trenches. The semiconductor device further includes a dielectric in the third trench covering a bottom side and walls of the third trench.

Abstract: A semiconductor device and a method for manufacturing the same are disclosed, which include a gate electrode material in a recess or a buried gate cell structure, a polysilicon material doped with impurities over a sidewall of a recess located over the gate electrode material, and a junction formed by an annealing or a rapid thermal annealing (RTA) process, thereby establishing a degree overlap between a gate electrode material of a buried gate and a junction.

Abstract: A vertical super junction MOSFET and a lateral MOSFET are integrated on the same semiconductor substrate. The lateral MOSFET is electrically isolated from the vertical super junction MOSFET by an n-buried isolating layer and an n-diffused isolating layer. The lateral MOSFET is formed of a p-well region formed in an n?semiconductor layer bounded by the n-buried isolating layer and n-diffused isolating layer, an n-source region and n-drain region formed in the p-well region, and a gate electrode that covers a portion of the p-well region sandwiched by the n-source region and n-drain region. As the n-buried isolating layer is formed at the same time as an n-layer (3) of the vertical super junction MOSFET, it is possible to reduce cost. Also, it is possible to suppress parasitic action between the elements with the n-buried isolating layer.

Abstract: The disclosed method of manufacturing (110, 120, 130, 140) a semiconductor device (12) has the steps (112, 114, 116) of: forming at least one wall (33) of a body (44) of the semiconductor device (12) by etching at least one trench (22) for a gate (42) of the semiconductor device (12) into the body (44); and performing a slanted implantation doping (126, 128) into the at least one wall (33) of the body (44), after the etching (112) of the at least one trench (22) and prior to coating the at least one trench (22) with an insulating layer (29).

Abstract: In one embodiment, a semiconductor device includes a semiconductor substrate having a first groove; and a plurality of first pillars over the substrate. The plurality of first pillars is disposed beside the first groove. A first insulator is disposed in the first groove. A bit contact is disposed in the first groove and over the first insulator. The bit contact is coupled to side surfaces of the plurality of first pillars.

Abstract: Provided are a transistor of a semiconductor device and a method for manufacturing the same. A gate induced drain leakage (GIDL) current is reduced by decreasing a work function at an upper portion of a gate electrode, and a threshold voltage of the transistor is maintained by maintaining a work function at a lower portion of the gate electrode at a high level, thereby reducing a leakage current of the transistor and reducing a read time and a write time of the semiconductor device. The transistor of the semiconductor device includes: a recess with a predetermined depth in a semiconductor substrate; a first gate electrode disposed within the recess; and a second gate electrode disposed on the first gate electrode into which ions of one or more of nitrogen (N), oxygen (O), arsenic (As), aluminum (Al), and hydrogen (H) are doped.

Abstract: A 3-dimensional non-volatile memory device, a memory system including the same, and a method of manufacturing the same comprise vertical channel layers protruding from a substrate, a plurality of interlayer insulating layers and a plurality of conductive layers alternately formed along the vertical channel layers, a charge trap layer surrounding the vertical channel layers, the charge trap layer having a smaller thickness in a plurality of first regions, interposed between the plurality of conductive layers and the vertical channel layers, than in a plurality of second regions, interposed between the plurality of interlayer insulating layers and the vertical channel layers and a blocking insulating layer formed in each of the plurality of first regions, between the plurality of conductive layers and the charge trap layer.

Abstract: According to one embodiment, an SiC semiconductor device including a p-type 4H—SiC region formed on at least part of a surface portion of an SiC substrate, a first gate insulating film formed on the 4H—SiC region and formed of a 3C—SiC thin film having p-type dopant introduced therein, a second gate insulating film formed on the first gate insulating film, and a gate electrode formed on the second gate insulating film.

Abstract: A field-effect transistor has a gate, a source, and a drain. The gate has a via extending through a semiconductor chip substrate from one surface to an opposite surface of the semiconductor chip substrate. The source has a first toroid of ion dopants implanted in the semiconductor chip substrate surrounding one end of the via on the one surface of the semiconductor chip substrate. The drain has a second toroid of ion dopants implanted in the semiconductor chip substrate surrounding an opposite end of the via on the opposite surface of the semiconductor chip substrate.

Abstract: A semiconductor device includes a trench region extending into a drift zone of a semiconductor body from a surface. The semiconductor device further includes a dielectric structure including a first step and a second step along a lateral side of the trench region. The semiconductor device further includes an auxiliary structure of a first conductivity type between the first step and the second step, a gate electrode in the trench region and a body region of a second conductivity type other than the first conductivity type of the drift zone. The auxiliary structure adjoins each one of the drift zone, the body region and the dielectric structure.

Abstract: A semiconductor device includes a first region and a second region, a buried gate arranged in the first region, and an oxidation prevention barrier surrounding the first region.

Abstract: Provided are a non-volatile memory devices having a stacked structure, and a memory card and a system including the same. A non-volatile memory device may include a substrate. A stacked NAND cell array may have at least one NAND set and each NAND set may include a plurality of NAND strings vertically stacked on the substrate. At least one signal line may be arranged on the substrate so as to be commonly coupled with the at least one NAND set.

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 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: The present invention is a semiconductor device including a first electrode over a substrate; a pair of oxide semiconductor films in contact with the first electrode; a second electrode in contact with the pair of oxide semiconductor films; a gate insulating film covering at least the first electrode and the pair of oxide semiconductor films; and a third electrode that is in contact with the gate insulating film and is formed at least between the pair of oxide semiconductor films. When the donor density of the oxide semiconductor films is 1.0×1013/cm3 or less, the thickness of the oxide semiconductor films is made larger than the in-plane length of each side of the oxide semiconductor films which is in contact with the first electrode.

Abstract: Methods and systems for forming multigate devices and systems are disclosed. In accordance with one such method, a fin is formed on a semiconductor substrate including a carbon-doped semiconductor layer. Further, a first portion of semiconductor material that is beneath the fin is removed to form a void beneath the fin by etching the material such that the fin is supported by at least one supporting pillar of the semiconducting material and such that the carbon-doped semiconductor layer prevents the etching from removing at least a portion of the fin. A dielectric material is deposited in the void to isolate the fin from a second portion of semiconductor material that is below the void. In addition, source and drain regions are formed in the fin and a gate structure is formed over the fin to fabricate the multigate device such that the dielectric material reduces current leakage beneath the device.

Abstract: A method of manufacturing a power device includes forming a first drift region on a substrate. A trench is formed by patterning the first drift region. A second drift region is formed by growing n-gallium nitride (GaN) in the trench, and alternately disposing the first drift region and the second drift region. A source electrode contact layer is formed on the second drift region. A source electrode and a gate electrode are formed on the source electrode contact layer. A drain electrode is formed on one side of the substrate which is an opposite side of the first drift region.

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: A MOSFET device has a funnel-shaped trench etched in a semiconductor substrate. The funnel-shaped trench has flared rim extending from a wider cross section trench mouth at the surface of the semiconductor substrate to a narrower cross section trench body portion which terminates in an epilayer portion of the semiconductor substrate. A gate electrode is disposed in the trench on the flared rim. Source and gate regions of the device abut upper and lower portions of the flared rim, respectively. A drain region of the device, which abuts the narrower cross section trench body portion, is self-aligned with a lower edge of a gate electrode.