Patents by Inventor Naohiro Matsukawa
Naohiro Matsukawa 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).
-
Publication number: 20230282747Abstract: The semiconductor wiring has the N-well layer of the impurity layer in the P substrate formed in the region where the poly wiring and P substrate face each other, wherein the N-well layer is electrically floating, is not used as a circuit element, and does not input or output signals. The semiconductor wiring is used as a transmission path of a high voltage signal, and used for a wiring that transmits a write signal of information at the memory cell array of the semiconductor memory device.Type: ApplicationFiled: May 12, 2023Publication date: September 7, 2023Applicant: KIOXIA CORPORATIONInventors: Takao SUEYAMA, Naohiro MATSUKAWA, Keiko KANEDA
-
Publication number: 20200203529Abstract: The semiconductor wiring has the N-well layer of the impurity layer in the P substrate formed in the region where the poly wiring and P substrate face each other, wherein the N-well layer is electrically floating, is not used as a circuit element, and does not input or output signals.Type: ApplicationFiled: September 12, 2019Publication date: June 25, 2020Applicant: Toshiba Memory CorporationInventors: Takao SUEYAMA, Naohiro MATSUKAWA, Keiko KANEDA
-
Patent number: 9183000Abstract: According to one embodiment, a memory system includes a nonvolatile semiconductor storage able to hold data, a temperature measurement section configured to measure the temperature of the semiconductor storage, a temperature varying section configured to change the temperature of the semiconductor storage, and a control circuit including a transmitter configured such that data received from a host is transferred to the semiconductor storage, and a temperature storage configured to store temperature information received from the temperature measurement section.Type: GrantFiled: August 29, 2012Date of Patent: November 10, 2015Assignee: KABUSHIKI KAISHA TOSHIBAInventors: Makoto Ichida, Hiroshi Sukegawa, Naohiro Matsukawa
-
Publication number: 20130227268Abstract: According to one embodiment, a memory system includes a nonvolatile semiconductor storage able to hold data, a temperature measurement section configured to measure the temperature of the semiconductor storage, a temperature varying section configured to change the temperature of the semiconductor storage, and a control circuit including a transmitter configured such that data received from a host is transferred to the semiconductor storage, and a temperature storage configured to store temperature information received from the temperature measurement section.Type: ApplicationFiled: August 29, 2012Publication date: August 29, 2013Inventors: Makoto ICHIDA, Hiroshi Sukegawa, Naohiro Matsukawa
-
Patent number: 8400833Abstract: A method of evaluating a semiconductor storage device of a floating gate type has calculating an electron density distribution of a tunnel insulating film of a memory cell by multiplying a change rate of a threshold voltage Vt of the memory cell of the semiconductor storage device with respect to the change of the logarithm of a time with ?*Cr*2k/Tox/q (where ? is the permittivity of the tunnel insulating film of the memory cell, Cr indicates a coupling ratio of the memory cell, Tox indicates the thickness of the tunnel insulating film, k indicates an attenuation rate of the existence probability when the charges are detrapped and is represented as k=(2mE/(h/2?)2)0.5, m indicates the mass of the electron, E indicates an energy level of the trap of the tunnel insulating film, h indicates a Planck's constant, and ? indicates a circumference ratio).Type: GrantFiled: March 23, 2011Date of Patent: March 19, 2013Assignee: Kabushiki Kaisha ToshibaInventor: Naohiro Matsukawa
-
Publication number: 20120081965Abstract: A method of evaluating a semiconductor storage device of a floating gate type has calculating an electron density distribution of a tunnel insulating film of a memory cell by multiplying a change rate of a threshold voltage Vt of the memory cell of the semiconductor storage device with respect to the change of the logarithm of a time with ?*Cr*2k/Tox/q (where ? is the permittivity of the tunnel insulating film of the memory cell, Cr indicates a coupling ratio of the memory cell, Tox indicates the thickness of the tunnel insulating film, k indicates an attenuation rate of the existence probability when the charges are detrapped and is represented as k=(2mE/(h/2?)2)0.5, m indicates the mass of the electron, E indicates an energy level of the trap of the tunnel insulating film, h indicates a Planck's constant, and ? indicates a circumference ratio).Type: ApplicationFiled: March 23, 2011Publication date: April 5, 2012Applicant: Kabushiki Kaisha ToshibaInventor: Naohiro MATSUKAWA
-
Patent number: 5650961Abstract: A cell characteristic measuring circuit for a nonvolatile memory is provided which, with the use of one circuit can satisfy both the requirements necessary to a characteristic evaluation using a cell array TEG and reliability evaluation using a memory circuit. The measuring circuit comprises a cell array having a matrix array of NAND strings each having a plurality of series-connected cell transistors, a first select gate and a second select gate connected in series. The cell array is divided into a plurality of blocks, a select gate line is connected to the gates of first select gates in each NAND string in the same block, and a word line is connected to the control gates of cell transistors in each row. A first external terminal is connected to a selected bit line, and a second external terminal is connected to each word line in the plurality of blocks.Type: GrantFiled: August 9, 1995Date of Patent: July 22, 1997Assignee: Kabushiki Kaisha ToshibaInventors: Toshihiko Himeno, Naohiro Matsukawa
-
Patent number: 5559736Abstract: After data is written into a desired memory cell of a memory cell array, a booster circuit verifies the threshold voltage of the memory cell in which data is written. An erase timing signal generation circuit connected to a control circuit generates a timing signal for a short period of time when a memory cell having a threshold voltage higher than the power supply voltage. An erasing voltage generation circuit applies a negative erasing voltage to the memory cell in which data is written for a short period of time according to the timing signal supplied from the erase timing signal generation circuit to slightly lower the threshold voltage of the memory cell so as to prevent the excessive writing.Type: GrantFiled: April 19, 1995Date of Patent: September 24, 1996Assignee: Kabushiki Kaisha ToshibaInventors: Naohiro Matsukawa, Keniti Imamiya, Toshiharu Watanabe, Michiharu Matsui
-
Patent number: 5515327Abstract: An EEPROM in which a select transistor to which any memory cell not selected is turned off to inhibit electron injections into the floating gate of the memory cell not selected. The memory cells of the EEPROM are arranged in rows and columns in a substrate. The memory cells forming each column are connected in series. The two endmost memory cells are connected to two select transistors, respectively. The bit lines are connected to a data latch/sense amplifier, which is connected to a column decoder. The column decoder controls the bit lines. A row decoder controls select gates and control gates. A voltage-boosting circuit generates a high voltage, which is applied to the substrate and the select gates to erase data in the EEPROM, and to the control gates to write data into the EEPROM. A low-voltage controller generates a low voltage, which is applied to the select gates for turning off the select transistors of the column not selected, thereby to prevent data-writing.Type: GrantFiled: December 20, 1994Date of Patent: May 7, 1996Assignee: Kabushiki Kaisha ToshibaInventors: Naohiro Matsukawa, Ryouhei Kirisawa, Riichiro Shirota
-
Patent number: 5350938Abstract: A memory cell transistor includes a semiconductor substrate, a N-type source region, a N-type drain region, a control gate and a P.sup.+ -type emitter region, which is formed in the surface region of the drain region. An insulating film overlies the source region, the drain region, the emitter region, and the control gate. A contact hole is formed in the insulating film so that the surface of the emitter region is exposed. An emitter electrode is formed in and around the contact hole. A PNP vertical bipolar transistor is constituted by the semiconductor substrate serving as a collector region, a P.sup.+ -type buried layer serving as a collector contact, and the drain region serving as a base region.Type: GrantFiled: June 26, 1991Date of Patent: September 27, 1994Assignee: Kabushiki Kaisha ToshibaInventors: Naohiro Matsukawa, Junichi Miyamoto
-
Patent number: 5172196Abstract: A nonvolatile semiconductor memory device has n.sup.+ -type source and drain regions formed in the surface of a p-type semiconductor substrate, a floating gate formed above and insulated from a channel region provided between the source and drain regions, and a control gate formed above and insulated from the floating gate. The memory device further has a capacitor provided between the control gate and drain region.Type: GrantFiled: November 21, 1989Date of Patent: December 15, 1992Assignee: Kabushiki Kaisha ToshibaInventors: Naohiro Matsukawa, Yoshihisa Mizutani
-
Patent number: 4845530Abstract: In a reduced projection type step- and repeat-exposure apparatus of the present invention, the angle of inclination of an exposure area on the wafer is first detected, and then corrected on the basis of the detected value. This measurement corrects the inclination of the exposure area. Hence, high precision patterning can be realized, even if an optical system having a small focus margin is used.Type: GrantFiled: December 8, 1987Date of Patent: July 4, 1989Assignee: Kabushiki Kaisha ToshibaInventor: Naohiro Matsukawa
-
Patent number: 4642881Abstract: A method of manufacturing a nonvolatile semiconductor memory device having a gate oxide layer including a relatively thin silicon dioxide layer. This gate oxide layer including the thin silicon dioxide layer is formed by the steps of forming the gate oxide film on a semiconductor element region in a silicon substrate; removing a portion of the gate oxide film to expose a portion of the silicon substrate; implanting impurity ions in the exposed portion of the substrate to an extent that a peak concentration of the impurity ions exceeds a solid solution limit at a temperature of the following thermal annealing step; activating the implanted impurity by thermal annealing so as to form a high impurity concentration layer and thermally oxidizing a surface of the high impurity concentration layer to form the thin silicon dioxide layer.Type: GrantFiled: May 17, 1985Date of Patent: February 17, 1987Assignee: Kabushiki Kaisha ToshibaInventors: Naohiro Matsukawa, Sigeru Morita, Hiroshi Nozawa
-
Patent number: 4620361Abstract: A method for producing a semiconductor device comprises a step of forming a first gate insulation layer on a portion of a single crystal silicon substrate and forming a floating gate of polycrystalline silicon on the first gate insulation layer, a step of forming an oxide layer on the exposed portion of the substrate and on the floating gate, and a step of forming a control gate on the floating gate through the oxide layer. In the formation of the oxide layer, a nitride pattern layer is formed on the floating gate, the entire structure is oxidized by using the nitride pattern layer as a mask, thus forming a protective layer on the exposed portion of the substrate, the nitride pattern layer is removed, and the entire structure is again oxidized, thus forming a second gate insulation layer on the floating gate.Type: GrantFiled: May 17, 1985Date of Patent: November 4, 1986Assignee: Kabushiki Kaisha ToshibaInventors: Naohiro Matsukawa, Hiroshi Nozawa, Shigeru Morita
-
Patent number: 4610078Abstract: There is disclosed a method of manufacturing a semiconductor device comprising a step of forming an isolation film having a patterned hole on a major surface of a semiconductor substrate of a P conductivity type, the wall of the isolation film defining the patterned hole having a large step, a step of forming a polysilicon layer on the major surface of the structure, a step of forming a first interlaid SiO.sub.2 layer on the polysilicon layer, a step of patterning the SiO.sub.2 layer and polysilicon layer using reactive ion etching process, thereby forming on the region of the substrate a gate electrode and a first SiO.sub.2 film superposed thereon, the continuous side wall of the gate electrode and first SiO.sub.2 film having a large step, a step of implanting an impurity ion into the substrate using the first SiO.sub.2 film as a mask, thereby forming an impurity diffused region of an N conductivity type in the substrate, a step of forming a second interlaid SiO.sub.Type: GrantFiled: December 21, 1984Date of Patent: September 9, 1986Assignee: Kabushiki Kaisha ToshibaInventors: Naohiro Matsukawa, Hiroshi Nozawa
-
Patent number: 4592026Abstract: In a memory device, a plurality of memory cells are connected to bit line pairs. A precharge circuit is controlled by a chip enable signal during a stand-by state and by an address transition detector signal during an active state, to charge the bit line pairs up to a given power source voltage.Type: GrantFiled: December 23, 1983Date of Patent: May 27, 1986Assignee: Shaibaura Denki Kabushiki KaishaInventors: Naohiro Matsukawa, Mitsuo Isobe, Takayasu Sakurai
-
Patent number: 4573143Abstract: A semiconductor memory device has at least one memory cell which includes first and second tunnel diodes connected in series in a forward-bias direction between first and second power source terminals. The first and second power source terminals are held at constant potentials. A switching MOS transistor is connected at one end to a connection point between the first and second tunnel diodes. The potential at the connection point between the first and second tunnel diodes is determined by the potential at the other end of the switching MOS transistor.Type: GrantFiled: March 7, 1983Date of Patent: February 25, 1986Assignee: Tokyo Shibaura Denki Kabushiki KaishaInventor: Naohiro Matsukawa
-
Patent number: 4459325Abstract: A method for element isolation utilizing insulating materials in a semiconductor substrate is proposed. In this method an oxidizable material layer of polycrystalline silicon or the like is formed and then the oxidizable material layer is selectively oxidized, using an oxidation-proof mask thereby forming a thick oxide layer. Thereafter, the oxidation-proof mask is removed and unoxidized oxidizable material below the mask is perpendicularly etched off, leaving part of the oxidizable material which is then oxidized to form together with the thick oxide layer an element isolation. This invention further proposes a semi-conductor device having element isolation layer whose bird's beak is very small in length.Type: GrantFiled: November 3, 1981Date of Patent: July 10, 1984Assignee: Tokyo Shibaura Denki Kabushiki KaishaInventors: Hiroshi Nozawa, Junichi Matsunaga, Naohiro Matsukawa
-
Patent number: 4419142Abstract: A method of manufacturing a semiconductor device which comprises the steps of: forming on a semiconductor substrate a layer of a material more quickly oxidizable than the semiconductor substrate; selectively oxidizing only that portion of the layer which is mounted on the element region of the semiconductor substrate; removing at least part of said oxidized layer; and wet oxidizing the retained portion of said more oxidizable material layer to provide an element-isolating oxide layer.Type: GrantFiled: October 20, 1981Date of Patent: December 6, 1983Assignee: Tokyo Shibaura Denki Kabushiki KaishaInventor: Naohiro Matsukawa