Patents by Inventor Kaoru Narita

Kaoru Narita 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: 5869871
    Abstract: In a semiconductor device including a semiconductor substrate, first and second external terminals, a first impurity diffusion region connected to the first external terminal, and second and third impurity diffusion regions forming a MIS transistor, one of the second and third impurity diffusion regions facing the first impurity region is connected to the second external terminal. The distance between the first diffusion region and the MIS transistor is substantially smaller than a certain value compared to conventional device.
    Type: Grant
    Filed: July 18, 1997
    Date of Patent: February 9, 1999
    Assignee: NEC Corporation
    Inventor: Kaoru Narita
  • Patent number: 5859451
    Abstract: A memory cell comprising a MOSFET formed on a principle surface of a semiconductor substrate and an information storage capacitor having a storage electrode formed in or on the substrate so as to contact with a drain region of the MOSFET, and a capacitor electrode formed adjacent to the storage electrode with a capacitor insulator film being sandwiched between the storage electrode and the capacitor electrode. The storage electrode is connected to the drain region of the MOSFET through a thin barrier layer which is formed between the drain region and the storage electrode region so as to prevent impurities in the storage electrode from being diffused into the drain region.
    Type: Grant
    Filed: June 19, 1991
    Date of Patent: January 12, 1999
    Assignee: NEC Corporation
    Inventor: Kaoru Narita
  • Patent number: 5844281
    Abstract: An input terminal and an input protective resistor of an N-type diffusion layer connected thereto are provided on a P-type semiconductor substrate. First and second N-type MOS transistors for internal circuit are connected to a grounding wiring at respective source diffusion layers. The first MOS transistor is located at closer distance from the input protective resister than the second MOS transistor. The source diffusion layer of the first MOS transistor and the grounding wiring are connected via a high melting point metal layer wiring, such as a tungsten silicide or so forth to increase a resistance to improve electrostatic breakdown potential. Accordingly, the distance between the input protective resistor and the first MOS transistor can be made smaller to eliminate dead space around the input protective resistor to enable reduction of a chip area.
    Type: Grant
    Filed: January 11, 1996
    Date of Patent: December 1, 1998
    Assignee: NEC Corporation
    Inventor: Kaoru Narita
  • Patent number: 5828107
    Abstract: When an element of an internal circuit is arranged in the vicinity of an input/output terminal of an LSI chip, electrostatic break down is caused in an internal circuit element by discharge current generated between an input/output terminal and a grounding terminal or a power source terminal. Therefore, the elements are arranged with a distance to cause dead space therebetween to make down-sizing of the LSI chip difficult. Therefore, a resistor is disposed between an input/output terminal and a protection element connected thereto. The resistor causes increasing of resistance of a current path from the input/output terminal to the grounding terminal, at the common wiring. Thus influence of the electrostatic break down for the element of the internal circuit can be restricted to permit location of the resistor to permit the internal circuit element to be arranged in the vicinity of the protection element of the input/output terminal.
    Type: Grant
    Filed: November 8, 1996
    Date of Patent: October 27, 1998
    Assignee: NEC Corporation
    Inventor: Kaoru Narita
  • Patent number: 5724219
    Abstract: A semiconductor device according to this invention comprises a first power supply (Vcc) wiring, a second power supply (Gnd) wiring, a first, a second and a third protective elements (3-1, 3-2 and 3-3), a first connecting wiring which connects in common one ends of the first, the second and the third protective elements, a second connecting wiring which connects the other ends of the first, the second and the third protective elements, and a third connecting wiring which connects the first connecting wiring and the first power supply wiring. The third connecting wiring has a resistance which is higher than that of the first connecting wiring.
    Type: Grant
    Filed: May 30, 1996
    Date of Patent: March 3, 1998
    Assignee: NEC Corporation
    Inventor: Kaoru Narita
  • Patent number: 5717559
    Abstract: An input/output protection device for protecting an internal circuit of an integrated circuit formed on a P-type substrate, from an electrostatic discharge (ESD), includes a thyristor connected between a terminal connected to the internal circuit and a common wiring conductor. The protection device comprises a N-well formed in the P-type substrate, a first P-type diffused region formed in the N-well and connected to the terminal, a first N-diffused region formed to adjoin the first N-well, a second P-type diffused region formed in close proximity to the first N-type diffused region, and a second N-type diffused region formed in the P-type substrate and connected to the common wiring conductor. An external resistor is connected between the first P-type diffused region and the first N-type diffused region, and another external resistor is connected between the second P-type diffused region and the second N-type diffused region.
    Type: Grant
    Filed: July 26, 1996
    Date of Patent: February 10, 1998
    Assignee: NEC Corporation
    Inventor: Kaoru Narita
  • Patent number: 5710452
    Abstract: A semiconductor device includes a metallic main line connected between an external terminal and an internal circuit, and a plurality of divided protection bipolar transistors connected in parallel to one another. Each of the divided protection bipolar transistors includes a collector and an emitter composed of first and second N diffused regions formed in a semiconductor substrate which are separated from each other. Each of the divided protection bipolar transistors also includes a base formed of a portion of a semiconductor substrate between the collector and the emitter. The collector is connected to a metallic sub line branched from the main line, and the emitter is connected to ground. The plurality of divided protection bipolar transistors have an equal breakdown voltage between the collector of the divided protection bipolar transistor and the semiconductor substrate.
    Type: Grant
    Filed: April 3, 1996
    Date of Patent: January 20, 1998
    Assignee: NEC Corporation
    Inventor: Kaoru Narita
  • Patent number: 5706156
    Abstract: A semiconductor device has a protective circuitry including a common discharge line, a first protective device connected between one of input/output terminals and the discharge line, and a second protective device connected between one of Vcc and ground terminals and the discharge line. The second protective device has an on-resistance as much as 1/2 of the on-resistance of the first protective device. Each of the power terminals and ground terminals generally has a large capacitance to accumulate a large amount of electric charge during a CDM test after charging of the semiconductor device as a whole. The low on-resistance prevents the inner circuit and input/output buffers of the semiconductor device from being applied with a higher potential during subsequent grounding of the semiconductor device in the CDM test.
    Type: Grant
    Filed: January 25, 1996
    Date of Patent: January 6, 1998
    Assignee: NEC Corporation
    Inventor: Kaoru Narita
  • Patent number: 5689120
    Abstract: The present invention provides a field effect transistor comprising the following elements. An insulation film is provided on a semiconductor substrate. The insulation film has an opening positioned on a predetermined region of the semiconductor substrate. A first polysilicon film is provided over the insulation film. A second polysilicon film is provided in contact with the first polysilicon film. The second polysilicon film extends on inside walls of the opening of the insulation film and over a peripheral portion of the predetermined region of the semiconductor substrate so that the first polysilicon film is connected through the second polysilicon film to the peripheral portion in the predetermined region of the semiconductor substrate.
    Type: Grant
    Filed: October 15, 1996
    Date of Patent: November 18, 1997
    Assignee: NEC Corporation
    Inventor: Kaoru Narita
  • Patent number: 5559362
    Abstract: In a semiconductor device having two metal connection layers formed on a scribe line area, the metal connection layers are connected to each other and further to a semiconductor substrate. The two metal connection layers are connected to each other via contact holes arranged along the scribe line area. This enhances heat dissipation and heat conductivity to allow heat to be rapidly transferred to the semiconductor substrate.
    Type: Grant
    Filed: October 17, 1994
    Date of Patent: September 24, 1996
    Assignee: NEC Corporation
    Inventor: Kaoru Narita
  • Patent number: 5521413
    Abstract: On the surface of a p-type semiconductor substrate, an n-type diffusion layer is formed. The diffusion layer is in contact with an aluminum wiring via a contact hole formed through an interlayer insulation layer to electrical connection. Immediately beneath the contact portion of the aluminum wiring, a contact n-type diffusion layer having higher impurity concentration than the n-type diffusion layer and having deeper junction depth. Outside of the contact n-type diffusion layer is surrounded by a low impurity concentration n well. With the construction, when an electrostatic pulse is applied to an external terminal connected to the shallow diffusion layer, junction breakdown of the diffusion layer can be successfully prevented.
    Type: Grant
    Filed: November 23, 1994
    Date of Patent: May 28, 1996
    Assignee: NEC Corporation
    Inventor: Kaoru Narita
  • Patent number: 5449939
    Abstract: A semiconductor device has an internal circuit, an output transistor and a protective transistor for protecting the output transistor and the internal circuit against an ESD-induced destruction caused by a surge pulse entering from an input/output terminal. The sum of a first distance between a contact for connecting an input/output terminal with the collector of the protective transistor and a field oxide film and a second distance between a contact for connecting the input/output terminal with the emitter of the protective transistor and the field oxide film overlying the base of the laterally formed protective transistor is made smaller than the sum of a third distance between a contact for connecting the input/output terminal with the drain of the output transistor and the gate electrode of the output transistor and a fourth distance between a contact for connecting a potential line with the source of the output transistor and the gate electrode of the output transistor.
    Type: Grant
    Filed: December 27, 1994
    Date of Patent: September 12, 1995
    Assignee: NEC Corporation
    Inventors: Yoko Horiguchi, Kaoru Narita
  • Patent number: 5436487
    Abstract: In an output circuit having first and second MOS transistors in series between a first power supply line and a second power supply line, and a third MOS transistor, the gates of the first and second transistors are connected to first and second input nodes, respectively, and an output node is provided between the first and second MOS transistors. The third MOS transistor is connected between one of the input nodes and the output node. The gate of the third MOS transistor is connected to a third power supply line.
    Type: Grant
    Filed: May 25, 1994
    Date of Patent: July 25, 1995
    Assignee: NEC Corporation
    Inventor: Kaoru Narita
  • Patent number: 5307310
    Abstract: A dynamic random access memory comprises a p-type semiconductor substrate and a plurality of first n-type diffused regions embedded in the substrate so that they extend along a first axis of the substrate parallel with first and second, opposed major surfaces of the substrate to form parallel bit lines. A matrix array of insulated gate electrodes extend along a second axis of the substrate normal to the first axis from the first major surface into the first n-type diffused regions, so that those of the insulated gate electrodes which are arranged along rows of the matrix are connected together by the parallel bit lines. Second n-type diffused regions are embedded in the substrate adjacent to the first major surface as well as to corresponding ones of the insulated gate electrodes.
    Type: Grant
    Filed: August 9, 1991
    Date of Patent: April 26, 1994
    Assignee: NEC Corporation
    Inventor: Kaoru Narita
  • Patent number: 5256564
    Abstract: In order to prevent a passivation film on an inner wall of a contact hole from being thinned to thereby improve an ability of the passivation film, an interlayer insulating film is formed on a semiconductor substrate in a surface region of which a diffusion layer is formed and a contact hole is formed therethrough to expose the diffusion layer. An aluminum wiring layer covering the inner wall of the contact hole and in contact with the diffusion layer is formed, on which a first thin passivation film is formed. After burying the contact hole with a polyimide layer, a second thick passivation film is formed.
    Type: Grant
    Filed: May 22, 1992
    Date of Patent: October 26, 1993
    Assignee: NEC Corporation
    Inventor: Kaoru Narita
  • Patent number: 5170232
    Abstract: In a n-channel MOS transistor of LDD structure with sidewall spacers, a p-type diffusion layer is formed to be on the surface of a n.sup.- drain layer just underneath the sidewall spacer and to be separated from the channel region. The low impurity concentration drain layer therefore becomes separated from the sidewall spacer, and thus degradation incident to LDD due to injection of hot carriers into the sidewall spacer can be prevented.
    Type: Grant
    Filed: June 4, 1991
    Date of Patent: December 8, 1992
    Assignee: NEC Corporation
    Inventor: Kaoru Narita