Patents by Inventor Ryoiku Togei

Ryoiku Togei 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: 4672408
    Abstract: A non-volatile memory device which stores data by capturing charges in an amorphous semiconductor layer. The amorphous semiconductor layer is provided between a gate electrode and a semiconductor substrate via an insulating film and its edge is in contact with at least the one of the source or drain electrodes in the semiconductor substrate. When a high voltage (10 V or higher) is applied to the gate electrode, an electric field is generated and thereby charges are injected into the amorphous semiconductor layer from the source and/or drain electrode and a write operation is thus carried out. An erasing operation is carried out by injection of charges of inverse polarity. This memory device offers advantages of low operating voltage and excellent charge sustaining characteristic, resulting from the fact that the write operation is attained independently of the gate insulating film.
    Type: Grant
    Filed: March 17, 1986
    Date of Patent: June 9, 1987
    Assignee: Fujitsu Limited
    Inventor: Ryoiku Togei
  • Patent number: 4571607
    Abstract: The capacity of a capacitor constituted by a metal-insulator-semiconductor layer configuration varies depending on the quantity of electric charge staying in the neighborhood of the interface between the insulating layer and the semiconductor layer. Because interleaving of a thin semiconductor layer between the insulating layer and the semiconductor layer to form a P-N junction therebetween is effective to confine some quantity of electric charge in the thin semiconductor layer, the capacity of the capacitor can be regulated. When the quantity of electric charge confined in the thin semiconductor layer is given in the form of an electric pulse signal, the signal can be memorized in the form of capacity.
    Type: Grant
    Filed: January 26, 1984
    Date of Patent: February 18, 1986
    Assignee: Fujitsu Limited
    Inventor: Ryoiku Togei
  • Patent number: 4330849
    Abstract: Disclosed herein is a semiconductor memory device comprising a semiconductor substrate having a first conductivity type, first and second regions of a second conductivity type opposite to said first type formed in the surface of the semiconductor substrate and separated with a certain space therebetween, a third region of the first conductivity type formed in the second region, and a gate electrode formed on an insulating film on the semiconductor substrate between the first and the third regions. By applying a gate voltage to the gate electrode, charge carriers are transferred between the first and second regions in accordance with the data to be stored. The stored data is read out by applying a prescribed gate voltage to the gate electrode and by detecting the value of the current between the third region and the semiconductor substrate.
    Type: Grant
    Filed: August 27, 1980
    Date of Patent: May 18, 1982
    Assignee: Fujitsu Limited
    Inventors: Ryoiku Togei, Yoshihiko Hika
  • Patent number: 4292091
    Abstract: A method of producing a semiconductor device comprises a step of forming a field isolating oxide layer from an amorphous silicon layer by oxidation at a relatively low temperature. Prior to the oxidizing treatment, a portion of the amorphous silicon layer is recrystallized into a single-crystalline silicon layer by laser irradiation.
    Type: Grant
    Filed: February 25, 1980
    Date of Patent: September 29, 1981
    Assignee: VLSI Technology Research Association
    Inventor: Ryoiku Togei
  • Patent number: 4247863
    Abstract: Disclosed herein is a small-sized semiconductor memory device, wherein an N.sup.+ (P.sup.+)-type single region having an input function and an output function and an electrode for controlling the electrical potential in a P(N)-type Si substrate are provided on the top surface of the P(N)-type Si substrate. In order to store carriers, i.e., an information, in the bulk of the substrate, an N (P)-type buried layer is formed below the N.sup.+ (P.sup.+)-type input-output region, mentioned above. Information is quickly transferred from or into the buried layer by means of the punch-through effect, which is realized by spreading a depletion layer formed at a PN junction between the input-output region and the Si substrate. Since the carriers are stored in the bulk of the substrate, the size of the memory device is reduced and the surface property of the device does not exert a harmful influence on the carriers.
    Type: Grant
    Filed: August 30, 1978
    Date of Patent: January 27, 1981
    Assignee: Fujitsu Limited
    Inventor: Ryoiku Togei
  • Patent number: 4228444
    Abstract: On a semiconductor substrate (or layer) of one conductivity type, a semiconductor layer of the opposite conductivity type is formed and a source and a drain region of the same conductivity type as the semiconductor substrate are formed in the semiconductor layer. Junctions are respectively formed between the source and drain regions and the semiconductor layer at such positions where punch-through may easily occur between the source and drain regions and the semiconductor substrate when operating voltages are applied to these regions. A local potential distribution generation electrode, which makes an ohmic contact with the semiconductor layer, is formed between the source and drain regions.
    Type: Grant
    Filed: September 29, 1978
    Date of Patent: October 14, 1980
    Assignee: Fujitsu Limited
    Inventor: Ryoiku Togei
  • Patent number: 4062037
    Abstract: A semiconductor memory device, which comprises: a P-type semiconductor material comprising on the surface thereof, an N-type doped layer, one surface region of the substrate adjoining the doped layer being used as a gate region, and further comprising in the interior thereof an N-type buried layer below another surface region of said substrate adjoining said one surface region. Electric charges representing information are stored in the buried layer. The reading time and the refreshing period are improved by shortening said reading time and lengthening said refreshing time utilization of said N-type buried layer.
    Type: Grant
    Filed: April 15, 1976
    Date of Patent: December 6, 1977
    Assignee: Fujitsu Limited
    Inventors: Ryoiku Togei, Akira Takei, Kunihiko Wada
  • Patent number: 4060796
    Abstract: A semiconductor memory device provided with one transferring electrode, one gate electrode and one diode of a charge coupled device is produced by a process with a reduced number of steps of diffusion and patterning. Both electrodes consists of doped polycrystalline silicon and both are electrically connected to a resistive layer which consists of non-doped polycrystalline silicon. A potential barrier between the region of both electrodes is removed due to the resistive layer. Resistive layer is formed by utilization of a two-stage deposition of the polycrystalline silicon layer with appropriate mashing steps.
    Type: Grant
    Filed: January 11, 1977
    Date of Patent: November 29, 1977
    Assignee: Fujitsu Limited
    Inventors: Ryoiku Togei, Akira Takei, Yoshihiko Hika, Kunihiko Wada
  • Patent number: 4031608
    Abstract: A semiconductor memory device provided with one transferring electrode, one gate electrode and one diode of a charge coupled device is produced by a process with a reduced number of steps of diffusion and patterning. Both electrodes consist of doped polycrystalline silicon and both are electrically connected to a resistive layer which consists of non-doped polycrystalline silicon. A potential barrier between the region of both electrodes is removed due to the resistive layer. The resistive layer is formed by utilization of a two stage deposition of the polycrystalline silicon layer with appropriate masking steps.
    Type: Grant
    Filed: April 8, 1976
    Date of Patent: June 28, 1977
    Assignee: Fujitsu Ltd.
    Inventors: Ryoiku Togei, Akira Takei, Kunihiko Wada
  • Patent number: 3996658
    Abstract: A distance between two electrodes of a CCD device is reduced to an extremely small value, thereby increasing the memory density, of the CCD device. In the process of the present invention, upon formation of a first electrode, an insulating layer is formed on the entire top surface of the semiconductor wafer. The material of another electrode is then placed on the entire top surface of the wafer. These layers are then selectively removed to form a CCD structure.
    Type: Grant
    Filed: March 30, 1976
    Date of Patent: December 14, 1976
    Assignee: Fujitsu Ltd.
    Inventors: Akira Takei, Yoshihiko Hika, Ryoiku Togei