Abstract: An improved structure and a manufacturing method of a vertical type power MOSFET having a super junction configuration is disclosed. The improved structure and the manufacturing method of the vertical type power MOSFET comprising: a step of preparing a semiconductor substrate SB including an n-type semiconductor layer SL and a p-type epitaxial layer EP on the semiconductor layer SL; a step of forming a trench GT in the p-type epitaxial layer EP by using an etching mask with a predetermined opening width; and a step of introducing an n-type impurity into a bottom portion of the trench GT using the etching mask with the predetermined opening width, whereby forming an n-type column NC at the bottom of trench GT and reaching the semiconductor layer SL.

Abstract: Variations of characteristics of a semiconductor device provided with a power MOSFET having a super junction structure are suppressed, and reliability of the semiconductor device is improved. A trench embedding an insulating film, which constitutes an insulator column therein, is formed in a first main surface of a semiconductor substrate whose crystal plane is a (110) plane. A crystal plane of a side surface of the trench in a short-side direction is a (111) plane, and a p-type diffusion layer constituting a p-column is formed in the above-mentioned side surface.

Abstract: Reliability of a semiconductor device is improved by suppressing occurrence of variation in characteristics of the semiconductor device provided with a power MOSFET that has a super junction structure. A fixed charge layer FC is formed in a trench T2 that is formed in an upper surface of a semiconductor substrate SB and is adjacent to a p type body region BD and an n type drift layer DL. The fixed charge layer FC constituting a p column accumulates holes in the semiconductor substrate SB located at a side surface of the trench T2 to form a hole accumulation region HC.

Abstract: In a trench gate type power MOSFET having a super-junction structure, both improvement of a breakdown voltage of a device and reduction of on-resistance are achieved. The trench gate and a column region are arranged so as to be substantially orthogonal to each other in a plan view, and a base region (channel forming region) and the column region are arranged separately in a cross-sectional view.

Abstract: The semiconductor device according to one embodiment includes a semiconductor substrate having a first surface and a second surface on an opposite side of the first surface, a gate insulating film formed on the first surface, a gate formed on the first surface via the gate insulating film, a source region formed in the first surface side of the semiconductor substrate, a body region formed so as to be in contact with the source region and including a channel region, a drain region formed in the second surface side of the semiconductor substrate, and a drift region formed so as to be in contact with the second surface side of the body region and the first surface side of the drain region. The semiconductor substrate has at least one concave portion formed in the second surface and being recessed toward the first surface.

Abstract: A Semiconductor device includes a substrate and a thermal conductive film. The substrate has a top surface and a back surface which oppose with each other. A first opening is formed on the back surface of substrate. The thermal conductive film includes a first thermal conductive portion formed in the first opening. The first thermal conductive portion is embedded in the first opening such that a void is formed in the first opening.

Abstract: In a trench gate type power MOSFET having a super-junction structure, both improvement of a breakdown voltage of a device and reduction of on-resistance are achieved. The trench gate and a column region are arranged so as to be substantially orthogonal to each other in a plan view, and a base region (channel forming region) and the column region are arranged separately in a cross-sectional view.

Abstract: A gallium oxide diode includes: a gallium oxide substrate having an n-type gallium oxide drift layer; an anode electrode of a metal film formed over a front surface of the n-type gallium oxide drift layer; a cathode electrode formed over a rear surface of the gallium oxide substrate; and a reaction layer of a metal oxide film of p-type conductivity formed between the anode electrode and the n-type gallium oxide drift layer. Further, a manufacturing method of a gallium oxide diode includes steps of forming an anode electrode of a metal film over an n-type gallium oxide drift layer formed over a gallium oxide substrate; and forming a reaction layer between the anode electrode and the n-type gallium oxide drift layer by performing a heat treatment to the gallium oxide substrate after forming the anode electrode, the reaction layer being made of a metal oxide film with p-type conductivity.

Abstract: A Semiconductor device includes a substrate and a thermal conductive film. The substrate has a top surface and a back surface which oppose with each other. A first opening is formed on the back surface of substrate. The thermal conductive film includes a first thermal conductive portion formed in the first opening. The first thermal conductive portion is embedded in the first opening such that a void is formed in the first opening.

Abstract: An airbag apparatus cover has a module cover with a module cover main body, and a door frame with a door frame movable member and a door frame fixed member. When an inflator discharges gas, the door frame movable member is moved upward by an expanding airbag. The module cover is broken along a tear line, and a door portion is cut off and separated from the surrounding module cover. The door portion is moved farther upward with the door frame movable member, and a tear line of the door portion is burst as it is pressed by the airbag. The door portion and its lining plate portions open like a door, and the airbag is expanded into a vehicle cabin. The fixed member, the movable member, and the module cover are integrally formed by a double-shot molding process, which facilitates the manufacture of the cover with high dimensional accuracy.

Abstract: An airbag apparatus cover has a module cover with a module cover main body, and a door frame with a door frame movable member and a door frame fixed member. When an inflator discharges gas, the door frame movable member is moved upward by an expanding airbag. The module cover is broken along a tear line, and a door portion is cut off and separated from the surrounding module cover. The door portion is moved farther upward with the door frame movable member, and a tear line of the door portion is burst as it is pressed by the airbag. The door portion and its lining plate portions open like a door, and the airbag is expanded into a vehicle cabin. The fixed member, the movable member, and the module cover are integrally formed by a double-shot molding process, which facilitates the manufacture of the cover with high dimensional accuracy.

Abstract: An airbag apparatus cover has a module cover with a module cover main body, and a door frame with a door frame movable member and a door frame fixed member. When an inflator discharges gas, the door frame movable member is moved upward by the expanding airbag. The module cover is broken along a tear line, and a door portion is cut off and separated from the surrounding module cover. The door portion is further moved upward with the door frame movable member, and a tear line of the door portion is burst as it is pressed by the airbag. The door portion and its lining plate portions open like a door, and the airbag is expanded into a vehicle cabin. The fixed member, the movable member, and the module cover are a double-shot molded integrally formed unit, thus facilitating the manufacture of a cover with high dimensional accuracy.

Abstract: An airbag cover mold includes a core member and a cavity member, and a resin material is supplied to a cavity between the core member and the cavity member. The core member has a plate-shaped blade block that functions as a protruding piece for forming a tear line. The blade block has openings for allowing the resin material to flow from one side of the blade block to the other side. An edged portion is provided at the top edge of each opening so as to point downward. Injection of the resin material is started after the blade block is moved to the cavity. After the injection, the blade block is moved outward to form the tear line. The mold provides an airbag cover in which smoothness in a region around a tear line is ensured.

Abstract: A vertical MOSFET of the present invention comprises a semiconductor wafer having a groove selectively etching in the semiconductor wafer to have substantially vertical side walls. The groove is oxidized using local oxidation of silicon (LOCOS) at 1100.degree. C. or greater to form a LOCOS film on the semiconductor wafer in the groove so that a whole side surface of said semiconductor wafer exposed by the groove is substantially vertical and essentially flat. The LOCOS film in the groove is removed and a thermal insulating film on the semiconductor wafer in the groove. Then a gate electrode made of a conductive film is formed on the thermal insulating film. An interlayer insulating film is formed on the gate electrode and a source electrode is formed in ohmic contact with a source region and a base region. A drain electrode is connected to the opposite side of the semiconductor wafer.

Abstract: A method of manufacturing a MOSFET having a p-type gate electrode made of polycrystalline silicon formed through a gate insulating film on a surface of a conductive semiconductor substrate. The gate electrode contains an n-type impurity in addition to a boron impurity. Low threshold voltage can be obtained with less fluctuation. Preferably, the n-type impurity is phosphorus and/or arsenic, and the concentration thereof ranges from 5.times.10.sup.18 to 1.times.10.sup.20 cm.sup.-3. A channel, which is formed in the surface of the gate insulating film side of the substrate, preferably has a positive polarity.

Abstract: A vertical type field effect transistor includes N-type base regions formed on the surface of a P-type semiconductor substrate, a P-type source region formed in each of the N-type base regions, a gate insulating film formed between the P-type source regions, and a gate electrode formed of polysilicon on the gate insulating film. The transistor has the P-type source regions, the N-type base regions and a lower portion of the P-type semiconductor substrate as three terminals. A method for manufacturing the transistor comprises the steps of: forming the gate insulating film; growing a polysilicon layer; performing ion injection of an N-type impurity for the grown polysilicon layer; and performing heat treatment after the ion injection.

Abstract: A two-way conductive directional circuit formed in a polycrystalline silicon layer separated by an insulation film from a semiconductive element is one-way biased for sensing a temperature of the semiconductive element. The directional circuit may be provided with a bias in either conductive direction thereof for sensing a temperature of the semiconductive element, before being provided with a bias in the other conductive direction thereof for sensing the temperature of the semiconductive element.

Abstract: An air bag-containing cover comprising:a soft surface skin layer made of a thermoplastic polymer containing the following ingredients A, B, C and D:ingredient A: a hydrogenated derivative of a block copolymer comprising styrene an conjugated diene,ingredient B: an olefinic resin,ingredient C: polyisobutylene with a viscosity average molecular weight of not greater than 70,000, andingredient D: a hydrocarbon series rubber softening agent with a kinetic viscosity at 40.degree. C. of not greater than 500 cSt and/or polybutene with a number average molecular weight of not greater than 2500, in which blending ratio is:ingredient A=40 to 80% by weight,ingredient B=5 to 30% by weightingredient C=2 to 30% by weightingredient D=0 to 20% by weight, and having a JIS-A hardness according to JIS-K6301 of from 20 to 90, anda rigid core layer comprising an olefinic resin having a modulus in flexure according to JIS-K7203 of from 1000 to 7000 kg/cm.sup.

Abstract: A cover for accommodating an air bag, which is provided at its inner surface with an array of spaced holes for starting tear at a start of an operation of the air bag, is characterized in that ends of the holes in the direction of the array have acute shapes converging toward the adjacent holes, respectively.

Abstract: A cover for a vehicle air bag comprises an external surface layer injection-molded from a thermoplastic material having a JIS-A hardness of 20 to 90 and a core layer injection-molded from a thermoplastic material having a bending elastic modulus (JIS K 7203) of not less than about 1000 kg/cm.sup.2 and a hardness greater than that of the surface layer. The core has weakened zones along which the cover breaks when the air bag is inflated.