Patents by Inventor Masami Yamaoka

Masami Yamaoka has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5250449
    Abstract: The present invention has as an object the provision of a vertical type semiconductor device whereby miniaturization and lowered ON resistance of the cell can be achieved without impairing the functioning of the device.The line width of the gate electrode is made smaller to meet the demand for miniaturization of the cell, but the distance between the channel regions diffused into the portions below the gate at the time of double diffusion is kept to be virtually equal to that in the device of larger cell size having a low J.sub.FET resistance component. Here, the reason for making the line width of the gate electrode smaller is for securing an area for the source contact.The point is that, while the width of the gate electrode is set to be smaller, the mask members as the mask for double diffusion, having the width allowing the source region to diffuse to the portion under the gate, are attached to the side walls of the gate electrode.
    Type: Grant
    Filed: September 30, 1991
    Date of Patent: October 5, 1993
    Assignee: Nippondenso Co., Ltd.
    Inventors: Akira Kuroyanagi, Masami Yamaoka, Yoshifumi Okabe
  • Patent number: 5248623
    Abstract: A diode which includes a first region formed in a polycrystalline silicon layer formed on a substrate. The diode has a predetermined width W and is one of an intrinsic region and a region including impurities at a low concentration therein, a second region and a third region including P-type impurities and N-type impurities therein respectively and both being oppositely arranged from each other with the first region therebetween in the polycrystalline silicon layer. Electrodes are electrically connected to the second region and the third region respectively, and further the film characteristic of the polycrystalline silicon layer and the predetermined width W thereof are determined in such a manner as to fulfill the following equation:W.sub.D .ltoreq.W.ltoreq.LL represents a carrier diffusion length and W.sub.
    Type: Grant
    Filed: October 7, 1991
    Date of Patent: September 28, 1993
    Assignee: Nippondenso Co., Ltd.
    Inventors: Hiroshi Muto, Masami Yamaoka
  • Patent number: 5242862
    Abstract: A semiconductor device including an N-type semiconductor substrate which includes arsenic as an impurity, a first electrode formed on a main surface of the N-type semiconductor substrate, a ground surface formed on another surface of the N-type semiconductor substrate, a second electrode formed on the ground surface and ohmically-contacted with the N-type semiconductor substrate, a semiconductor element formed in the N-type semiconductor substrate and flowing current between the first electrode and the second electrode during ON-state thereof. The device has a reduced ON-resistance thereof.
    Type: Grant
    Filed: February 8, 1991
    Date of Patent: September 7, 1993
    Assignee: Nippondenso Co., Ltd.
    Inventors: Yoshifumi Okabe, Masami Yamaoka, Akira Kuroyanagi
  • Patent number: 5204282
    Abstract: A semiconductor circuit structure including a semiconductor substrate portion and at least one region provided on one main surface thereof insulatedly isolated from other regions provided on the same surface, by an burying means made of an oxide film, the burying means including a bottom flat portion and at least one side wall portion provided at least in the vicinity of an edge portion of and integrally formed with the bottom flat portion, thereby a semiconductor circuit structure provided with a plurality of insulatedly isolated regions on a main surface thereof and having a high withstand voltage can be obtained in a short production process.
    Type: Grant
    Filed: June 29, 1990
    Date of Patent: April 20, 1993
    Assignee: Nippon Soken, Inc.
    Inventors: Kazuhiro Tsuruta, Seizi Huzino, Mitutaka Katada, Tadashi Hattori, Masami Yamaoka
  • Patent number: 5168337
    Abstract: A diode which includes a first region formed in a polycrystalline silicon layer formed on a substrate. The diode has a predetermined width W and is one of an intrinsic region and a region including impurities at a low concentration therein, a second region and a third region including P-type impurities and N-type impurities therein respectively and both being oppositely arranged from each other with the first region therebetween in the polycrystalline silicon layer. Electrodes are electrically connected to the second region and the third region respectively, and further the film characteristic of the polycrystalline silicon layer and the predetermined width W thereof are determined in such a manner as to fulfill the following equation:W.sub.D .ltoreq.W.ltoreq.LL represents a carrier diffusion length and W.sub.
    Type: Grant
    Filed: April 8, 1992
    Date of Patent: December 1, 1992
    Assignee: Nippondenso Co., Ltd.
    Inventors: Hiroshi Muto, Masami Yamaoka
  • Patent number: 5164218
    Abstract: A semiconductor device of vertical arrangement includes an anode region formed of a first semiconductor substrate and a second semiconductor substrate joined with the first semiconductor substrate. The first semiconductor substrate forms a high-resistance layer with a predetermined impurity density, and the second semiconductor substrate forms a low-resistance layer whose impurity density is higher than that of the high-resistance layer. A PN junction is formed inside the first semiconductor substrate. The periphery of the first semiconductor substrate including the PN junction is configured in an inverted mesa structure and coated with an insulation material. With this arrangement, the semiconductor device has a high withstand voltage and enables an employment of a large diameter wafer.
    Type: Grant
    Filed: July 17, 1991
    Date of Patent: November 17, 1992
    Assignee: Nippon Soken, Inc.
    Inventors: Kazuhiro Tsuruta, Mitutaka Katada, Seiji Fujino, Masami Yamaoka
  • Patent number: 5136348
    Abstract: A structure and manufacturing method for a thin film semiconductor device consisting of a single diode or a plurality of diodes connected in series, the device being formed of at least one pair of mutually adjacent P-type (23a) and N-type (23b) regions formed in a layer of polycrystalline silicon (23) deposited on an insulating film (22) upon a substrate (21), to thereby define at least one PN junction. Each of the p-type regions and N-type regions is shaped as a rectangle, with opposite ends of each PN junction formed between these regions being respectively defined by two opposing sides of the polycrystalline silicon layer. Since each of the PN junctions is substantially rectilinear, an even distribution of current flow through each PN junction is attained, whereby a high resistance to destruction and an extremely stable value of reverse bias breakdown voltage are achieved.
    Type: Grant
    Filed: January 28, 1991
    Date of Patent: August 4, 1992
    Assignee: Nippondenso Co., Ltd.
    Inventors: Yukio Tsuzuki, Masami Yamaoka, Hiroshi Muto
  • Patent number: 5128823
    Abstract: A power MOS transistor and a current sensing MOS transistor have a common drain electrode connected to a load. The gates of these MOS transistors are commonly controlled in response to an input control signal. A load current sensing resistor element is connected between the source electrodes of these transistors. A voltage signal sensed by the load sensing resistor element is amplified by a differential amplifier constituted by a pair of depletion type MOS transistors. The amplified output controls the MOS transistors, and the MOS transistors variably control a voltage of the input control signal to be supplied to the power and current sensing MOS transistors. The power MOS transistor, the current sensing MOS transistor, the depletion MOS transistor, the current control MOS transistor, and the like have the same conductivity type.
    Type: Grant
    Filed: June 14, 1989
    Date of Patent: July 7, 1992
    Assignee: Nippondenso Co., Ltd.
    Inventors: Hiroshi Fujimoto, Masami Yamaoka, Yukio Tsuzuki
  • Patent number: 5072277
    Abstract: A semiconductor device is provided which comprises a single crystalline substrate having a main surface, an insulating layer formed on the main surface of the single crystalline substrate, and a semiconductor region of a single crystal formed on the insulating layer, wherein the semiconductor region has top and bottom surfaces and a thickness of not more than 6 .mu.m and an impurity is doped in the semiconductor region from the top to bottom surfaces thereof, a concentration of the impurity gradually decreasing from the top to bottom surfaces, whereby the semiconductor region is made a first conductivity type by the doped impurity. The semiconductor device further comprises an insulating gate type field effect transistor including source and drain regions in the semiconductor region, the source and drain regions having a conductive type opposite to that of the first conductivity type, and further there is provided a process for manufacturing such a semiconductor device.
    Type: Grant
    Filed: July 9, 1990
    Date of Patent: December 10, 1991
    Assignee: Nippondenso Co., Ltd.
    Inventors: Toshio Sakakibara, Masami Yamaoka
  • Patent number: 4994880
    Abstract: Base regions of first and second stage transistors are formed in a semiconductor substrate consisting of low and high resistivity collector layers, and emitter regions are formed in the respective base regions. The emitter region of the second stage transistor has an interdigital structure with a plurality of finger portions, and an emitter surface electrode is formed on the emitter region of the second stage transistor. The second stage transistor emitter surface electrode has an extending portion at a position spaced apart from a transistor operation region where the finger portions are formed. An emitter connection electrode is formed on the extending portion, and a lead is connected by soldering or the like to the emitter connection electrode.
    Type: Grant
    Filed: September 25, 1989
    Date of Patent: February 19, 1991
    Assignee: Nippondenso Co., Ltd.
    Inventors: Naohito Kato, Yoshiyuki Miyase, Tomoatsu Makino, Kasuhiro Yamada, Masami Yamaoka, Takeshi Matsui, Masahiro Yamamoto, Yoshiki Ishida, Tohru Nomura
  • Patent number: 4896199
    Abstract: A semiconductor substrate has a power region and a control region. The control region is located in the center portion of the substrate, and the power region surrounds the control region and is separated therefrom. A vertical type, MOS transistor, i.e., an active semiconductor element, is formed on the power region. An insulation film is formed on part of the control region. A polycrystalline silicon diode, which functions as a heat-sensitive element, is formed on the insulation film. A control section comprising a lateral type, MOS transistor is also formed on the control region. The lateral type, MOS transistor is connected to receive a signal form the polycrystalline silicon diode. Further, a polycrystalline silicon resistor, which determines a circuit constant, is formed on the insulation film.
    Type: Grant
    Filed: March 16, 1988
    Date of Patent: January 23, 1990
    Assignee: Nippondenso Co., Ltd.
    Inventors: Yukio Tsuzuki, Masami Yamaoka
  • Patent number: 4879254
    Abstract: A method for manufacturing a DMOS which comprises forming a first conductive type layer on a substrate, forming a gate oxide layer thereon, forming a gate electrode layer and a second insulating layer successively on the gate oxide layer, forming a second conductive type body region and a first conductive type source region having a narrower width by implanting impurities utilizing the second insulating layer as a mask, forming a side wall spacer of an insulating material on at least a side portion of the gate electrode, forming a conductive passage penetrating the source region and extending into the body region while utilizing the second insulating layer and the side wall spacer as mask, optionally implanting the exposed body region, further excessively etching the sidewall spacer, the masking layer overlying the gate, and the gate oxide prior to providing an electrode connecting the source and body regions.
    Type: Grant
    Filed: June 9, 1988
    Date of Patent: November 7, 1989
    Assignee: Nippondenso Co., Ltd.
    Inventors: Yukio Tsuzuki, Masami Yamaoka
  • Patent number: 4760434
    Abstract: A semiconductor substrate has a power region and a control region. The control region is located in the center portion of the substrate, and the power region surrounds the control region and is separated therefrom. A vertical type, MOS transistor, i.e., an active semiconductor element, is formed on the power region. An insulation film is formed on part of the control region. A polycrystalline silicon diode, which functions as a heat-sensitive element, is formed on the insulation film. A control section comprising a lateral type, MOS transistor is also formed on the control region. The lateral type, MOS transistor is connected to receive a signal form the polycrystalline silicon diode. Further, a polycrystalline silicon resistor, which determines a circuit constant, is formed on the insulation film.
    Type: Grant
    Filed: November 28, 1986
    Date of Patent: July 26, 1988
    Assignee: Nippondenso Co., Ltd.
    Inventors: Yukio Tsuzuki, Masami Yamaoka
  • Patent number: 4680608
    Abstract: This application describes a semiconductor device having a power amplifier pattern consisting of a plurality of parallel-connected transistor unit cells with emitters thereof being arrayed like meshes, wherein the width of the emitter of each transistor unit cell is not in excess of 50 microns. The limitation of the emitter width contributes to enhancement of the reverse-bias breakdown endurance.
    Type: Grant
    Filed: February 1, 1985
    Date of Patent: July 14, 1987
    Assignee: Nippondenso Co., Ltd.
    Inventors: Yukio Tsuzuki, Masami Yamaoka, Shoji Toyoshima
  • Patent number: 4672402
    Abstract: In a semiconductor circuit device having a diode as an overvoltage protection element, a semiconductor substrate is comprised of an N-type collector substrate integral with a transistor. An N.sup.+ type collector diffusion layer is formed on the rear surface of the substrate. A P-type anode region and a N.sup.+ cathode region are formed in the major surface of the substrate so that they are spaced apart from each other and the N.sup.+ cathode region has the same type of impurity, but at a higher impurity concentration level than, the semiconductor substrate. An insulating film is formed on the surface of the resultant structure. A gate electrode is formed in an overlapping relation to the anode region and cathode region with an insulating film therebetween. A gate potential is established between the gate electrode and the underlying substrate.
    Type: Grant
    Filed: September 25, 1986
    Date of Patent: June 9, 1987
    Assignee: Nippondenso Co., Ltd.
    Inventors: Masami Yamaoka, Yukio Tsuzuki, Shoji Toyoshima