143results about How to "Reduce electric field concentration" patented technology

The invention discloses a high-flexible polymer matrix composite membrane with high energy density and a preparation method thereof. The composite membrane is composed of a polymer matrix and core-shell structured nano-fibre dispersed in the polymer matrix; the core layer of the core-shell structured nano-fibre is ceramic fibre; the shell layer is an organic matter coated layer, wherein the mass percentage of the polymer matrix is 50-95%; and the mass percentage of the core-shell structured nano-fibre is 5-50%. The polymer matrix and the core-shell structured nano-fibre are composited into the membrane by adopting a solution blending and tape casting method or a bidirectional membrane pulling method, so that a flexible polymer matrix composite material having the advantages of being good in dielectric property, high in breakdown field strength and high in energy density is obtained. The dielectric constant of the composite material can be modulated to 10-40 by adjusting the content of nano ceramic fibre; simultaneously, the dielectric loss Tan delta is kept to be less than 5%, the breakdown field strength is more than 210 kV/mm, and the energy density is 2-6 kJ/L; and the composite material is a material which can be used for capacitors and high power static energy storage.

A semiconductor device 1 includes a square substrate 2, first RESURF structures 3 in the shape of planar stripes on an element area 10 of a main surface of the substrate 2, a transistor T arranged between the first RESURF structures 3, a first high withstand voltage section 11 constituted by second RESURF structures 3a in the shape of planar strips on a periphery of the main surface of the substrate 2, and a second high withstand voltage section 12 constituted by third RESURF structures 3b which are symmetrically arranged at corners of the substrate 2 with respect to a diagonal line D of the main surface of the substrate 2.

The invention provides a semiconductor device and a method of manufacturing the same. The semiconductor device which provides compactness and enhanced drain withstand voltage. The semiconductor device includes: a gate electrode; a source electrode spaced from the gate electrode; a drain electrode located opposite to the source electrode with respect to the gate electrode in a plan view and spaced from the gate electrode; at least one field plate electrode located between the gate and drain electrodes in a plan view, provided over the semiconductor substrate through an insulating film and spaced from the gate electrode, source electrode and drain electrode; and at least one field plate contact provided in the insulating film, coupling the field plate electrode to the semiconductor substrate. The field plate electrode extends from the field plate contact at least either toward the source electrode or toward the drain electrode in a plan view.

The invention relates to a high-voltage insulation circuit board which is used in an electric power apparatus such as an electric power converter or the like such as power semiconductor device, inverter module, or the like and provides an insulation circuit board in which electric field concentration at the end sections of a wiring pattern is reduced, partial discharging is suppressed, and a reliability is high. According to the invention, there is provided an insulation circuit board having: a metal base substrate; and wiring patterns which are formed onto at least one of the surfaces of the metal base substrate through an insulation layer, characterized in that between two adjacent wiring patterns in which an electric potential difference exists among the wiring patterns, at least one or more wiring patterns or conductors which are in contact with the insulation layer and have an electric potential in a range of the electric potential difference between the adjacent wiring patterns are arranged. According to the invention, the electric field concentration at the end sections of the wiring pattern to which a high voltage is applied is reduced and partial-discharge-resistant characteristics are improved.

A method for manufacturing a semiconductor device includes the steps of: forming, on a principal face of a substrate, a semiconductor layer including a first semiconductor region of a first conductivity type; and forming, in the semiconductor layer, a trench having a bottom located in the first semiconductor region. The method further includes a step of forming a trench bottom impurity region being of a second conductivity type and covering the bottom of the trench by performing annealing to cause part of the semiconductor layer corresponding to an upper corner portion of the trench to move to be placed on the bottom of the trench.

In a silicon carbide semiconductor device, a p-type SiC layer is disposed in a corner of a bottom of a trench. Thus, even if an electric field is applied between a drain and a gate when a MOSFET is turned off, a depletion layer in a pn junction between the p-type SiC layer and an n⁻ type drift layer greatly extends toward the n⁻ type drift layer, and a high voltage caused by an influence of a drain voltage hardly enters a gate insulating film. Hence, an electric field concentration within the gate insulating film can be reduced, and the gate insulating film can be restricted from being broken. In this case, although the p-type SiC layer may be in a floating state, the p-type SiC layer is formed in only the corner of the bottom of the trench. Thus, the deterioration of the switching characteristic is relatively low.

The invention discloses a bidirectional spiral electrostatic spinning device, and relates to an electrostatic spinning device. The bidirectional spiral electrostatic spinning device is provided with bidirectional threaded guide rods, liquid storage sliders, vertical slide bars, guide rails, a framework, a controllable injection device, a liquid guide pipe, a liquid distributing device, a high-voltage power source, air pumps, pressure regulating valves, air guide pipes, partition plates, motors, driven belt pulleys, driving belt pulleys, V-shaped belts, air hole arrays and collecting devices. The bidirectional spiral electrostatic spinning device has the advantages that large-area and multi-jet injection effects can be realized by the aid of the bidirectional threaded guide rods, so that the electrostatic spinning efficiency further can be improved, phenomena of electrostatic interference among spinning jets and electric field concentration can be reduced, uniform distribution of nano-fibers on collecting plates can be promoted, the thickness uniformity of collected nano-fiber membranes can be improved, the quality of the nano-fiber membranes can be enhanced, the multiple jets can be assuredly stably and quickly injected, and large-area uniform nano-membranes can be collected; the bidirectional spiral electrostatic spinning device is applicable to injection devices with different bidirectional threaded guide rods and different thread shapes, and the lengths, the quantities and the shapes of the bidirectional threaded guide rods of the injection devices can be different from one another.

A semiconductor module includes an insulated circuit board that includes an insulating substrate, a first conductive plate arranged on a first principal surface of the insulating substrate and within the outer edges of the insulating substrate, and a second conductive plate arranged within the outer edges of the insulating substrate on a second principal surface of the insulating substrate that faces the first principal surface. Furthermore, boundary edges between the first principal surface of the insulating substrate and the side faces of the first conductive plate are covered by an ion gel that contains an ionic liquid.

In a conventional semiconductor device, there has been a problem that, in a region where a wiring layer to which a high electric potential is applied traverses a top surface of an isolation region, the withstand voltage is deteriorated. In a semiconductor device of the present invention, an epitaxial layer is deposited on a substrate, and an LDMOSFET is formed in one region divided by an isolation region. In a region where a wiring layer connected to a drain electrode traverses a top surface of the isolation region, a conductive plate having a ground electric potential and another conductive plate in a floating state are formed under the wiring layer. With this structure, electric field is reduced in the vicinity of the isolation region under the wiring layer, whereby a withstand voltage of the LDMOSFET is increased.

In first and second gate electrodes constituting a gate electrode, the gate length of the second gate electrode is set shorter than the gate length of the first gate electrode and short enough to produce the short channel effect. The threshold voltage of a second transistor corresponding to the second gate electrode can thereby be made lower than the threshold voltage of a first transistor corresponding to the first gate electrode. When the same voltage is applied to the first and second gate electrodes, an electric field concentration at the channel edge on the drain side is reduced. This in result reduces the channel length modulation effect.

An object is to reduce the adverse influence which a portion of a gate insulating layer where the thickness has decreased, that is, a step portion, has on semiconductor element characteristics so that the reliability of the semiconductor element is improved. A semiconductor layer is formed over an insulating surface; a side surface of the semiconductor layer is oxidized using wet oxidation to form a first insulating layer; a second insulating layer is formed over the semiconductor layer and the first insulating layer; and a gate electrode is formed over the semiconductor layer and the first insulating layer with the second insulating layer interposed therebetween.

There is provided a semiconductor device in which the degradation of electric characteristics can be inhibited. A semiconductor substrate has a main surface, and a trench in the main surface. A buried insulating film is buried in the trench. The trench has one wall surface and the other wall surface which oppose each other. A gate electrode layer is located over at least the buried insulating film. The trench has angular portions which are located between the main surface of at least either one of the one wall surface and the other wall and a bottom portion of the trench.

This silicon carbide semiconductor device has a substrate (1), drift layer (2), current dispersion layer (3), base region (4), source region (5), trench (7), gate insulating film (8), gate electrode (9), source electrode (12), drain electrode (14), and bottom layer (10). The current dispersion layer is formed on the drift layer, and has a first conductivity-type impurity concentration set higher than that of the drift layer. The bottom layer has a second conductivity type, is disposed below the base region, covers a bottom portion of the trench, including corner portions of the bottom portion of the trench, and has more depth than the current dispersion layer.

A device comprises a substrate, an n-layer and a p-layer, an n-electrode, and a p-electrode. A step is formed at an outer circumference of the device. A protective film is formed so as to continuously cover a side surface and a bottom surface of the step. A field plate electrode connected with the p-electrode is formed on the protective film. When a distance from the pn junction interface to the surface of the protective film on the bottom surface of the step is defined as h (μm), a dielectric constant of the protective film is defined as ∈_s, and a thickness of the protective film at the pn junction interface on the side surface of the step is defined as d (μm), (∈_s·h)/d is 4 or more, and ∈_s/d is 3 (1/μm) or more.

An object of the present invention is to provide a method for manufacturing electrodes that can effectively suppress edge-curl when metal electrodes such as bus electrodes and data electrodes are patterned mainly by a photolithography method.

In order to achieve the above object, in the manufacturing method in the present invention, an amount of undercut generated by difference in a degree of dissolution caused by developing solution is controlled, and baking is performed at a temperature such that glass in a protrusion formed at side edges becomes soft so as to touch a substrate by gravity. With such method for manufacturing, it becomes possible to make the side edges rounded whose curvature changes continuously.

A first trench is formed in a surface of an n⁺-type semiconductor substrate that forms a source region. A p-type base region, an n⁻-type drift region, and an n⁺-type drain region are deposited in this order in the first trench using epitaxial growth. A second trench extending from the source region to the drift region through the base region is formed in the surface. A gate insulating film and a gate electrode are formed on a surface defining the second trench. The n⁺-type drain region has a location where growing surfaces come together in epitaxial growth and where a defect is likely to occur, and the gate electrode lacks such a location and thus avoids an increase in normalized ON resistance. Therefore, the breakdown voltage remains high without increasing the ON resistance.

Disclosed is an LDMOS device, which is configured to reduce an electric field concentrated to a gate oxide film and lower an ON-resistance produced when the device conducts a forward action, and a method for manufacturing the same. More specifically, when an n-drift region is formed on a P-type substrate, a p-body is formed on the n-drift region through an epitaxial process, and then the p-body region is partially etched to form a plurality of p-epitaxial layers, so that when the device executes an action for blocking a reverse voltage, depletion layers are formed between the junction surfaces of the p-epitaxial layers and the n-drift region including the junction surfaces between the n-drift region and the p-body.

A Schottky metal 9 is in Schottky-contact with a center portion of a surface of an epitaxial layer 4. A peripheral trench 13 is formed by digging from the surface of the epitaxial layer 4 on a boundary portion between an active region 21 where the Schottky metal 9 is in Schottky-contact with the surface of the epitaxial layer 4 and a peripheral region 22 outside of the active region in a surface layer portion of the epitaxial layer 4. An insulating film 14 is formed on an entire area of inner wall surfaces of the peripheral trench 13. There is provided with a conductor 15 which is connected to the Schottky metal 9 and is opposed to the entire area of the inner wall surfaces of the peripheral trench 13 via the insulating film 14 in the peripheral trench 13.

The present invention relates to a semiconductor structure suitable for a charge-coupled device and a manufacturing method thereof. On the cross section of the semiconductor device, a second well region of a second conductivity type is provided in a first conductivity type drift region of a terminal protection region, The second well region of the second conductivity type is located in the upper part of the drift region of the first conductivity type, and a plurality of terminal trenches are arranged in the terminal protection zone, and the terminal trenches are located in the second well region of the second conductivity type, and the depth extends to into the drift region of the first conductivity type under the second well region of the second conductivity type; the termination dielectric body and the terminal conductor are filled in the termination trench, and the termination conductor is the same as the adjacent active region outside the termination trench The second conductivity type second well region on the side is electrically connected. The invention has a compact structure, can effectively improve the high-voltage resistance characteristic of the device, is compatible with the existing technology, reduces the cost, has wide application range, and is safe and reliable.

A protective diode has a basic structure including an n⁺ layer, an n⁻ layer, a p⁺ layer, and an n⁻ layer in this order. A p-type layer forming the protective diode is the p⁺ layer with high impurity concentration. Therefore, the spreading of a depletion layer is suppressed and it is possible to reduce the area of the protective diode. In addition, phosphorus ions with a large diffusion coefficient are implanted to form the n⁻ layer with low impurity concentration in the polysilicon layer forming the protective diode. A heat treatment is performed at a temperature of 1000° C. or higher to diffuse the phosphorus ions implanted into the polysilicon layer. Therefore, the impurity profile of the n⁻ layer in the depth direction can be uniformized in the depth direction.

A formation method of an element isolation film according to which a high-voltage transistor with an excellent characteristic can be formed is provided. On a substrate, a gate oxide film is previously formed. A CMP stopper film is formed thereon, and thereafter, a gate oxide film and a CMP stopper film are etched. The semiconductor substrate is etched to form a trench. Further, before the trench is filled with a field insulating film, an liner insulating film is formed at a trench interior wall, and a concave portion at the side surface of the gate oxide film under the CMP stopper film is filled with the liner insulating film. In this manner, formation of void in the element isolation film laterally positioned with respect to the gate oxide film can be prevented.