Abstract: Provided is a method of manufacturing a silicon carbide epitaxial wafer appropriate for suppressing an occurrence of a triangular defect. A method of manufacturing a silicon carbide epitaxial wafer includes: an etching process of etching a surface of a silicon carbide substrate at a first temperature using etching gas including H2; a process of flattening processing of flattening the surface etched in the etching process, at a second temperature using gas including H2 gas, first Si supply gas, and first C supply gas; and an epitaxial layer growth process of performing an epitaxial growth on the surface flattened in the process of flattening processing, at a third temperature using gas including second Si supply gas and second C supply gas, wherein the first temperature T1, the second temperature T2, and the third temperature T3 satisfy T1>T2>T3.

Abstract: A semiconductor device includes: a semiconductor substrate; a first gate trench and a second gate trench both extending from a first main surface of the semiconductor substrate into the semiconductor substrate; a semiconductor mesa delimited by the first and second gate trenches; and a field plate trench extending from the first main surface through the semiconductor mesa. The field plate trench includes a field plate separated from each sidewall and a bottom of the field plate trench by an air gap. The field plate is anchored to the semiconductor substrate at the bottom of the field plate trench by an electrically insulative material that occupies a space in a central part of the field plate, the electrically insulative material spanning the air gap to contact the semiconductor substrate at the bottom of the field plate trench. Methods of producing the semiconductor device are also described.

Abstract: A method of forming an insulation structure inside and on top of a first semiconductor substrate, including the steps of: a) forming a trench vertically extending in the first substrate from a first surface of the first substrate; b) filling the trench, from the first surface of the first substrate, with a polysilicon region; c) thinning the first substrate on the side of a second surface of the first substrate, opposite to the first surface, to expose the polysilicon region at the bottom of the trench; d) removing the polysilicon region from the second surface of the first substrate; and e) filling the trench, from the second surface of the first substrate, with a metal.

Abstract: Provided is a semiconductor device in which a first anode layer and a first contact layer are provided on a first main surface side in a diode region, and in which a second anode layer and a second contact layer are provided on the first main surface side in a boundary region. A concentration of impurities of a second conductive type of the second anode layer is lower than a concentration of impurities of the second conductive type of the first anode layer, or an occupied area ratio of the second contact layer with respect to the area where the emitter electrode is in contact with the semiconductor substrate in the boundary region is smaller than an occupied area ratio of the first contact layer with respect to the area where the emitter electrode is in contact with the semiconductor substrate in the diode region.

Abstract: Provided is a semiconductor device including a semiconductor substrate; a transistor portion provided in the semiconductor substrate; a current sensing portion for detecting current flowing through the transistor portion; an emitter electrode set to an emitter potential of the transistor portion; a sense electrode electrically connected to the current sensing portion; and a Zener diode electrically connected between the emitter electrode and the sense electrode. Provided is a semiconductor device fabricating method including providing a transistor portion in a semiconductor substrate; providing a current sensing portion for detecting current flowing through the transistor portion; providing an emitter electrode set to an emitter potential of the transistor portion; providing a sense electrode electrically connected to the current sensing portion; and providing a Zener diode electrically connected between the emitter electrode and the sense electrode.

Abstract: Provided is a semiconductor device having transistor and diode sections. The semiconductor device comprises: a gate metal layer provided above the upper surface of a semiconductor substrate; an emitter electrode provided above the upper surface of the semiconductor substrate; a first conductivity-type emitter region provided on the semiconductor substrate upper surface side in the transistor section; a gate trench section, which is provided on the semiconductor substrate upper surface side in the transistor section, is electrically connected to the gate metal layer, and is in contact with the emitter region; an emitter trench section, which is provided on the semiconductor substrate upper surface side in the diode section, and is electrically connected to the emitter electrode; and a dummy trench section, which is provided on the semiconductor substrate upper surface side, is electrically connected to the gate metal layer, and is not in contact with the emitter region.

Abstract: A method and structure for mitigating leakage current in devices that include a continuous active region. In some embodiments, a threshold voltage at the cell boundary is increased by changing a photomask logic operation (LOP) to reverse a threshold voltage type at the cell boundary. Alternatively, in some cases, the threshold voltage at the cell boundary is increased by performing a threshold voltage implant (e.g., an ion implant) at the cell boundary, and into a dummy gate disposed at the cell boundary. Further, in some embodiments, the threshold voltage at the cell boundary is increased by use of a silicon germanium (SiGe) channel at the cell boundary. In some cases, the SiGe may be disposed within the substrate at the cell boundary and/or the SiGe may be part of the dummy gate disposed at the cell boundary.

Abstract: An power semiconductor device having a barrier region is provided. A power unit cell of the power semiconductor device has at least two trenches that may both extend into the barrier region. The at least two trenches may both have a respective trench electrode coupled to a control terminal of the power semiconductor device. For example, the trench electrodes are structured to reduce the total gate charge of the power semiconductor device. The barrier region may be p-doped and vertically confined, i.e., in and against the extension direction, by the drift region. The barrier region can be electrically floating.

Abstract: A semiconductor device is provided that has a semiconductor substrate, a drift layer of a first conductivity type formed in the semiconductor substrate, a base region of a second conductivity type formed in the semiconductor substrate and above the drift layer, and an accumulation region of the first conductivity type provided between the drift layer and the base region and having an impurity concentration higher than an impurity concentration in the drift layer, wherein the accumulation region has a first accumulation region and a second accumulation region that is formed more shallowly than the first accumulation region is and on a side of a boundary with a region that is different from the accumulation region in a planar view.

Abstract: A wide band gap semiconductor device includes a semiconductor layer, a trench formed in the semiconductor layer, first, second, and third regions having particular conductivity types and defining sides of the trench, and a first electrode embedded inside an insulating film in the trench. The second region integrally includes a first portion arranged closer to a first surface of the semiconductor layer than to a bottom surface of the trench, and a second portion projecting from the first portion toward a second surface of the semiconductor layer to a depth below a bottom surface of the trench. The second portion of the second region defines a boundary surface with the third region, the boundary region being at an incline with respect to the first surface of the semiconductor layer.

Abstract: A semiconductor device of an embodiment includes: a first trench located in a silicon carbide layer extending in a first direction; a second trench and a third trench adjacent to each other in the first direction; n type first silicon carbide region; p type second silicon carbide region on the first silicon carbide region; n type third silicon carbide region on the second silicon carbide region; p type fourth silicon carbide region between the first silicon carbide region and the second trench; p type fifth silicon carbide region between the first silicon carbide region and the third trench; p type sixth silicon carbide region shallower than the second trench between the second trench and the third trench and having a p type impurity concentration higher than that of the second silicon carbide region; a gate electrode in the first trench; a first electrode, and a second electrode.

Abstract: A trenched MOS gate controlled rectifier has an asymmetric trench structure between the active area of active trenches and the termination area of termination trenches. The asymmetric trench structure has a gate electrode on one side of the trench to turn on and off the channel of the MOS structure effectively and a field plate structure on the other side with field dielectric sufficiently thick in order to sustain the high electric field during the reverse bias condition.

Abstract: A semiconductor device includes a substrate, first and second isolation layers, an insulation layer pattern, and a gate structure. The substrate has a cell region and a peripheral region. The first isolation layer is buried in a first upper portion of the substrate in the peripheral region. The second isolation layer is buried in a second upper portion of the substrate in the cell region, and extends along a first direction substantially parallel to a top surface of the substrate. The insulation layer pattern is buried in the first upper portion, and extends along a second direction substantially parallel to the top surface of the substrate and substantially perpendicular to the first direction. The insulation layer pattern has a lower surface higher than a lower surface of the second isolation layer, and applies a stress to a portion of the substrate adjacent thereto.

Abstract: A semiconductor on insulator (SOI) device may include a semiconductor handle substrate. The semiconductor hand may include a porous semiconductor layer, and an etch stop layer proximate the porous semiconductor layer. The SOI may also include an insulator layer on the etch stop layer. The SOI may further include a device semiconductor layer on the insulator layer.

Abstract: A vertical TVS (VTVS) circuit includes a semiconductor substrate for supporting the VTVS device thereon having a heavily doped layer extending to the bottom of substrate. Deep trenches are provided for isolation between multi-channel VTVS. Trench gates are also provided for increasing the capacitance of VTVS with integrated EMI filter.

Abstract: A method of monitoring an epitaxial growth geometry shift is disclosed. First, second and third trenches are formed on a semiconductor wafer. An epitaxial layer is grown. The epitaxial layer covers the first trenches and the second trenches but not the third trenches. First and second recesses on a top surface of the epitaxial layer are formed. First and second openings aligned with the first and the second recesses and a third openings aligned with the third trenches are formed in a photoresist layer. A corresponding first offset between a top center and a bottom center of each first recess is measured. An offset value of the top center from the bottom center of said each first recess is determined. A corresponding second offset between a top center of each second recess and a center of corresponding second opening is determined. A corresponding third offset between a center of each third trench and a center of corresponding third opening is measured.

Abstract: A semiconductor device employs surrounding gate transistors (SGTs) which are vertical transistors to constitute a CMOS NOR circuit. The NOR circuit is formed by using a plurality of MOS transistors arranged in m rows and n columns. The MOS transistors constituting the NOR circuit are formed on a planar silicon layer disposed on a substrate, and each have a structure in which a drain, a gate, and a source are arranged in a vertical direction, the gate surrounding a silicon pillar. The planar silicon layer includes a first active region having a first conductivity type and a second active region having a second conductivity type. The first active region and the second active region are connected to one another via a silicon layer formed on a surface of the planar silicon layer. This provides for a semiconductor device that constitutes a NOR circuit.

Abstract: A vertical transistor and a manufacturing method thereof are provided herein. The manufacturing method includes forming a first patterned conductive layer on a substrate; forming a patterned metal oxide layer on the first patterned conductive layer, in which the patterned metal oxide layer includes a first patterned insulator layer, a second patterned insulator layer, and a second patterned conductive layer; forming a semiconductor layer; and forming a third patterned conductive layer. The first patterned insulator layer, the second patterned insulator layer, and the second patterned conductive layer are made by using a single metal oxide material. The oxygen concentration of the second patterned conductive layer is different from the oxygen concentrations of the first patterned insulator layer and the second patterned insulator layer.

Abstract: A semiconductor device includes: metal collector layer on backside, P-type collector layer, N-type field stop layer, N-drift layer and N-type CS layer within the N-drift layer near the top side. Multiple trench structures are formed by polysilicon core and gate oxide layer near the front side. There are active cells and plugged cells on top of the device. The polysilicon cores of the trenches in the active cells are connected to the gate electrode, and the polysilicon cores of the trenches in the plugged cells are connected to the emitter electrode. There are N+ region and P+ region in active cells, and they are connected to metal emitter layer through the window in the insulation layer. There are P-well regions in both active cells and plugged cells. The P-well regions in active cells are continuous and connected to emitter electrode through P+ region. The P-well regions in plugged cells are divided by N-drift layer, forming discontinuous P-type regions along the direction of trenches.

Abstract: A semiconductor memory device and a manufacturing method of the semiconductor memory device are provided. The semiconductor memory device can include a substrate in which a cell area and a peripheral area are defined, a first gate insulating layer on the peripheral area, and a poly gate layer on the first gate insulating layer to form a combined stack, wherein the combined stack of the first gate insulating layer and the first poly gate layer is absent from the cell area.

Abstract: A transistor is disclosed that includes a semiconductor body having a first horizontal surface. A drift region is arranged in the semiconductor body. A plurality of gate electrodes is arranged in trenches of the semiconductor body. The trenches have a longitudinal direction and extending parallel relative to each other. The longitudinal direction of the trenches extends in a first lateral direction of the semiconductor body. The body regions and the source regions are arranged between the trenches. The body regions are arranged between the drift region and the source regions in a vertical direction of the semiconductor body. In the first horizontal surface, the source regions and the body regions are arranged alternately in the first lateral direction. A source electrode is electrically connected to the source regions and the body regions in the first horizontal surface.

Abstract: A silicon carbide layer includes a first region having a first conductivity type, a second region provided on the first region and having a second conductivity type, and a third region provided on the second region and having the first conductivity type. A trench having an inner surface is formed in the silicon carbide layer. The trench penetrates the second and third regions. The inner surface of the trench has a first side wall and a second side wall located deeper than the first side wall and having a portion made of the second region. Inclination of the first side wall is smaller than inclination of the second side wall.

Abstract: A semiconductor apparatus includes a substrate having a device region and a peripheral region located around the device region. A first semiconductor region is formed within the device region, is of a first conductivity type, and is exposed at an upper surface of the substrate. Second-fourth semiconductor regions are formed within the peripheral region. The second semiconductor region is of the first conductivity type, has a lower concentration of the first conductivity type of impurities, is exposed at the upper surface, and is consecutive with the first semiconductor region directly or indirectly. The third semiconductor region is of a second conductivity type, is in contact with the second semiconductor region from an underside, and is an epitaxial layer. The fourth semiconductor region is of the second conductivity type, has a lower concentration of the second conductivity type of impurities, and is in contact with the third semiconductor region from an underside.

Abstract: A semiconductor device includes a first-conductivity-type semiconductor layer including an active region in which a transistor having impurity regions is formed and a marginal region surrounding the active region, a second-conductivity-type channel layer formed between the active region and the marginal region and forming a front surface of the semiconductor layer, at least one gate trench formed in the active region to extend from the front surface of the semiconductor layer through the channel layer, a gate insulation film formed on an inner surface of the gate trench, a gate electrode formed inside the gate insulation film in the gate trench, and at least one isolation trench arranged between the active region and the marginal region to surround the active region and extending from the front surface of the semiconductor layer through the channel layer, the isolation trench having a depth equal to that of the gate trench.

Abstract: An electronic device can include a transistor structure, including a patterned semiconductor layer overlying a substrate and having a primary surface, wherein the patterned semiconductor layer defines a first trench and a second trench that extend from the primary surface towards the substrate. The electronic device can further include a first conductive electrode and a gate electrode within the first trench. The electronic device can still further include a second conductive electrode within the second trench. The electronic device can include a source region within the patterned semiconductor layer and disposed between the first and second trenches. The electronic device can further include a body contact region within the patterned semiconductor layer and between the first and second trenches, wherein the body contact region is spaced apart from the primary surface. Processes of forming the electronic device can take advantage of forming all trenches during processing sequence.

Abstract: A semiconductor device is provided that includes a fin having a first gate and a second gate formed on a first sidewall of the fin in a first trench, wherein the first gate is formed above the second gate. The device includes a third gate and a fourth gate formed on a second sidewall of the fin in a second trench, wherein the third gate is formed above the fourth gate. Methods of manufacturing and operating the device are also included. A method of operation may include biasing the first gate and the fourth gate to create a current path across the fin.

Abstract: In one embodiment, a semiconductor device includes an isolated trench-electrode structure. The semiconductor device is formed using a modified photolithographic process to produce alternating regions of thick and thin dielectric layers that separate the trench electrode from regions of the semiconductor device. The thin dielectric layers can be configured to control the formation channel regions, and the thick dielectric layers can be configured to reduce switching losses.

Abstract: Provided is a semiconductor device that can be manufactured at low cost and that can reduce a reverse leak current, and a manufacturing method thereof. A semiconductor device has: a source region and a drain region having a body region therebetween; a source trench that reaches the body region, penetrating the source region; a body contact region formed at the bottom of the source trench; a source electrode embedded in the source trench; and a gate electrode that faces the body region. The semiconductor device also has: an n-type region for a diode; a diode trench formed reaching the n-type region for a diode; a p+ region for a diode that forms a pn junction with the n-type region for a diode at the bottom of the diode trench; and a schottky electrode that forms a schottky junction with the n-type region for a diode at side walls of the diode trench.

Abstract: A semiconductor device includes a first-conductivity-type semiconductor layer including an active region in which a transistor having impurity regions is formed and a marginal region surrounding the active region, a second-conductivity-type channel layer formed between the active region and the marginal region and forming a front surface of the semiconductor layer, at least one gate trench formed in the active region to extend from the front surface of the semiconductor layer through the channel layer, a gate insulation film formed on an inner surface of the gate trench, a gate electrode formed inside the gate insulation film in the gate trench, and at least one isolation trench arranged between the active region and the marginal region to surround the active region and extending from the front surface of the semiconductor layer through the channel layer, the isolation trench having a depth equal to that of the gate trench.

Abstract: A semiconductor device includes a semiconductor diode. The semiconductor diode includes a drift region and a first semiconductor region of a first conductivity type formed in or on the drift region. The first semiconductor region is electrically coupled to a first terminal via a first surface of a semiconductor body. The semiconductor diode includes a channel region of a second conductivity type electrically coupled to the first terminal, wherein a bottom of the channel region adjoins the first semiconductor region. A first side of the channel region adjoins the first semiconductor region.

Abstract: A method for manufacturing a vertical trench IGBT includes: forming a body layer of a second conductivity type on a semiconductor substrate of a first conductivity type; forming a trench passing through the body layer; forming a trench gate in the trench via a gate insulating film; forming a polysilicon film containing an impurity of a first conductivity type on the body layer; diffusing the impurity from the polysilicon film into the body layer to form an emitter layer of a first conductivity type on the body layer; and forming a collector layer of a second conductivity type on a lower surface of the semiconductor substrate.

Abstract: A semiconductor device includes a semiconductor substrate having an active region defined by a device isolation structure. A recessed channel is formed on the semiconductor substrate under the active region. A recessed junction region is formed between the recessed channel and the device isolation structure adjacent to the recessed channel.

Abstract: An embodiment of the invention provides a semiconductor fabrication method. The method comprises forming an isolation region between a first and a second region in a substrate, forming a recess in the substrate surface, and lining the recess with a uniform oxide. Embodiments further include doping a channel region under the bottom recess surface in the first and second regions and depositing a gate electrode material in the recess. Preferred embodiments include forming source/drain regions adjacent the channel region in the first and second regions, preferably after the step of depositing the gate electrode material. Another embodiment of the invention provides a semiconductor device comprising a recess in a surface of the first and second active regions and in the isolation region, and a dielectric layer having a uniform thickness lining the recess.

Abstract: Disclosed herein are a semiconductor device, and a method for manufacturing the semiconductor device. The semiconductor device includes a semiconductor substrate, a base region formed on an upper region of an inside of the semiconductor substrate, at least one gate electrode that penetrates through the base region and has an inverted triangular shape, a gate insulating film formed to enclose an upper portion of the semiconductor substrate and the gate electrode, an inter-layer insulating film formed on an upper portion of the gate electrode and the gate insulating film, an emitter region formed inside the base region and on both sides of the gate electrode, an emitter metal layer formed on an upper portion of the base region and inter-layer insulating film, and a buffer region formed to enclose a lower portion of the gate electrode and to be spaced apart from the base region.

Abstract: An electronic device can include a transistor structure, including a patterned semiconductor layer overlying a substrate and having a primary surface, wherein the patterned semiconductor layer defines a first trench and a second trench that extend from the primary surface towards the substrate. The electronic device can further include a first conductive electrode and a gate electrode within the first trench. The electronic device can still further include a second conductive electrode within the second trench. The electronic device can include a source region within the patterned semiconductor layer and disposed between the first and second trenches. The electronic device can further include a body contact region within the patterned semiconductor layer and between the first and second trenches, wherein the body contact region is spaced apart from the primary surface. Processes of forming the electronic device can take advantage of forming all trenches during processing sequence.

Abstract: In an insulated-gate type semiconductor device in which a gate-purpose conductive layer is embedded into a trench which is formed in a semiconductor substrate, and a source-purpose conductive layer is provided on a major surface of the semiconductor substrate, a portion of a gate pillar which is constituted by both the gate-purpose conductive layer and a cap insulating film for capping an upper surface of the gate-purpose conductive layer is projected from the major surface of the semiconductor substrate; a side wall spacer is provided on a side wall of the projected portion of the gate pillar; and the source-purpose conductive layer is connected to a contact region of the major surface of the semiconductor substrate, which is defined by the side wall spacer.

Abstract: In one embodiment, a semiconductor device includes an isolated trench-electrode structure. The semiconductor device is formed using a modified photolithographic process to produce alternating regions of thick and thin dielectric layers that separate the trench electrode from regions of the semiconductor device. The thin dielectric layers can be configured to control the formation channel regions, and the thick dielectric layers can be configured to reduce switching losses.

Abstract: A method for manufacturing a vertical trench IGBT includes: forming a body layer of a second conductivity type on a semiconductor substrate of a first conductivity type; forming a trench passing through the body layer; forming a trench gate in the trench via a gate insulating film; forming a polysilicon film containing an impurity of a first conductivity type on the body layer; diffusing the impurity from the polysilicon film into the body layer to form an emitter layer of a first conductivity type on the body layer; and forming a collector layer of a second conductivity type on a lower surface of the semiconductor substrate.

Abstract: A semiconductor device includes a trench extending from a surface of a P-base layer to a surface of a P-well layer. The trench has a trench end portion defined in the surface of the P-well layer and in a direction in which the trench extends. The trench has first and second regions. The first region extends from the trench end portion to get into the surface of the P-base layer near a boundary between the P-base layer and the P-well layer. The second region extends in the surface of the P-base layer from an end portion of the first region. A trench width is greater in the first region than in the second region.

Abstract: The present invention discloses a semiconductor structure and a manufacturing method thereof. The semiconductor structure is formed in a first conductive type substrate, which has an upper surface. The semiconductor structure includes: a protected device, at least a buried trench, and at least a doped region. The protected device is formed in the substrate. The buried trench is formed below the upper surface with a first depth, and the buried trench surrounds the protected device from top view. The doped region is formed below the upper surface with a second depth, and the doped region surrounds the buried trench from top view. The second depth is not less than the first depth.

Abstract: Disclosed herein are methods for better variable height control of FinFET patterned fins. In one example, the method includes forming a layer on a substrate, patterning that layer to create trenches, and forming a common stack material in the trenches. Next, a pFET masking material is formed over a portion of the structure, and an nFET channel material is formed in the unmasked trenches. The pFET masking material is removed and an nFET masking material is formed over the portion of the structure that includes the nFET channel material, and a pFET channel material is formed in the unmasked trenches. Next, the unmasked patterned material is made flush with the pFET channel material, thereby creating a difference in height with the masked pattern material. Finally, the nFET masking material is removed and the patterned layer is recessed to expose pFET and nFET channel material fin structures of differing heights.

Abstract: A semiconductor device includes a semiconductor substrate which functions as an n? drift layer, a trench IGBT formed in the front surface, an interlayer insulator film, and a metal electrode layer on the interlayer insulator film. There is a contact hole in the interlayer insulating film which has a first opening formed on the metal electrode layer side and a second opening on the semiconductor substrate side. Width w1 of the first opening on the metal electrode layer side is wider than width w2 of first opening on the semiconductor substrate side, in a direction perpendicular to the extending direction of the trench in the planar pattern of trenches. The metal electrode layer is connected to a p-type channel region and an n+ source region via the contact hole. The method of manufacturing improves the reliability of the device.

Abstract: Semiconductor switching devices include a first wide band-gap semiconductor layer having a first conductivity type. First and second wide band-gap well regions that have a second conductivity type that is opposite the first conductivity type are provided on the first wide band-gap semiconductor layer. A non-wide band-gap semiconductor layer having the second conductivity type is provided on the first wide band-gap semiconductor layer. First and second wide band-gap source/drain regions that have the first conductivity type are provided on the first wide band-gap well region. A gate insulation layer is provided on the non-wide band-gap semiconductor layer, and a gate electrode is provided on the gate insulation layer.

Abstract: A semiconductor device includes a semiconductor diode. The semiconductor diode includes a drift region and a first semiconductor region of a first conductivity type formed in or on the drift region. The first semiconductor region is electrically coupled to a first terminal via a first surface of a semiconductor body. The semiconductor diode includes a channel region of a second conductivity type electrically coupled to the first terminal, wherein a bottom of the channel region adjoins the first semiconductor region. A first side of the channel region adjoins the first semiconductor region.

Abstract: A method of fabricating a saddle-fin transistor may include: forming a buffer oxide film and a hard mask oxide film over a semiconductor substrate; etching the buffer oxide film, the hard mask oxide film and the semiconductor substrate corresponding to a mask pattern to form a trench corresponding to a gate electrode and a fin region; oxidizing the exposed semiconductor substrate in the trench to form a gate oxide film; depositing a gate lower electrode in the trench; and depositing a gate upper electrode over the gate lower electrode to fill the trench.

Abstract: In an insulated-gate type semiconductor device in which a gate-purpose conductive layer is embedded into a trench which is formed in a semiconductor substrate, and a source-purpose conductive layer is provided on a major surface of the semiconductor substrate, a portion of a gate pillar which is constituted by both the gate-purpose conductive layer and a cap insulating film for capping an upper surface of the gate-purpose conductive layer is projected from the major surface of the semiconductor substrate; a side wall spacer is provided on a side wall of the projected portion of the gate pillar; and the source-purpose conductive layer is connected to a contact region of the major surface of the semiconductor substrate, which is defined by the side wall spacer.

Abstract: A semiconductor device includes: a substrate; and depletion and enhancement mode JFETs. The depletion mode JFET includes: a concavity on the substrate; a channel layer in the concavity; a first gate region on the channel layer; first source and drain regions on respective sides of the first gate region in the channel layer; first gate, source and drain electrodes. The enhancement mode JFET includes: a convexity on the substrate; the channel layer on the convexity; a second gate region on the channel layer; second source and drain regions on respective sides of the second gate region in the channel layer; second gate, source and drain electrodes. A thickness of the channel layer in the concavity is larger than a thickness of the channel layer on the convexity.

Abstract: A semiconductor device includes a first-conductivity-type semiconductor layer including an active region in which a transistor having impurity regions is formed and a marginal region surrounding the active region, a second-conductivity-type channel layer formed between the active region and the marginal region and forming a front surface of the semiconductor layer, at least one gate trench formed in the active region to extend from the front surface of the semiconductor layer through the channel layer, a gate insulation film formed on an inner surface of the gate trench, a gate electrode formed inside the gate insulation film in the gate trench, and at least one isolation trench arranged between the active region and the marginal region to surround the active region and extending from the front surface of the semiconductor layer through the channel layer, the isolation trench having a depth equal to that of the gate trench.

Abstract: An embodiment of the invention provides a semiconductor fabrication method. The method comprises forming an isolation region between a first and a second region in a substrate, forming a recess in the substrate surface, and lining the recess with a uniform oxide. Embodiments further include doping a channel region under the bottom recess surface in the first and second regions and depositing a gate electrode material in the recess. Preferred embodiments include forming source/drain regions adjacent the channel region in the first and second regions, preferably after the step of depositing the gate electrode material. Another embodiment of the invention provides a semiconductor device comprising a recess in a surface of the first and second active regions and in the isolation region, and a dielectric layer having a uniform thickness lining the recess.

Abstract: A method for manufacturing a semiconductor device includes the steps of: forming a trench in a semiconductor substrate; and forming an epitaxial film on the substrate including a sidewall and a bottom of the trench so that the epitaxial film is filled in the trench. The step of forming the epitaxial film includes a final step before the trench is filled with the epitaxial film. The final step has a forming condition of the epitaxial film in such a manner that the epitaxial film to be formed on the sidewall of the trench has a growth rate at an opening of the trench smaller than a growth rate at a position of the trench, which is deeper than the opening of the trench.