Patents by Inventor Hiroki Date
Hiroki Date 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).
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Publication number: 20240420782Abstract: According to one embodiment, a semiconductor memory device includes a first memory cell and a second memory cell arranged adjacent to each other and coupled in series; and a control circuit, wherein the control circuit is configured to: at a time of the program operation in a first program loop operation targeted for the first memory cell, during a first period, while suppling a first write voltage to the first memory cell, supply a first voltage smaller than the first write voltage to the second memory cell, and during a second period, while supplying a second voltage smaller than the first voltage to the first memory cell, supply a third voltage greater than the second voltage to the second memory cell.Type: ApplicationFiled: April 17, 2024Publication date: December 19, 2024Applicant: Kioxia CorporationInventor: Hiroki DATE
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Publication number: 20240339139Abstract: In a semiconductor memory device, in a write operation performed to a memory cell transistor, a first voltage is applied to a first word line and a second voltage lower than the first voltage is applied to a second word line. When a stop command is received during the write operation, a third voltage lower than the second voltage is applied to the first and second word lines, thereafter a fourth voltage higher than the third voltage is applied to a first selection line, thereon or thereafter a fifth voltage higher than the fourth voltage is applied to the first and second word lines, thereafter a sixth voltage lower than the fourth voltage is applied to the first selection line, and thereafter a seventh voltage is applied to the first and second word lines.Type: ApplicationFiled: June 18, 2024Publication date: October 10, 2024Applicant: Kioxia CorporationInventor: Hiroki DATE
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Patent number: 12051483Abstract: In a semiconductor memory device, in a write operation performed to a memory cell transistor, a first voltage is applied to a first word line and a second voltage lower than the first voltage is applied to a second word line. When a stop command is received during the write operation, a third voltage lower than the second voltage is applied to the first and second word lines, thereafter a fourth voltage higher than the third voltage is applied to a first selection line, thereon or thereafter a fifth voltage higher than the fourth voltage is applied to the first and second word lines, thereafter a sixth voltage lower than the fourth voltage is applied to the first selection line, and thereafter a seventh voltage is applied to the first and second word lines.Type: GrantFiled: April 26, 2022Date of Patent: July 30, 2024Assignee: Kioxia CorporationInventor: Hiroki Date
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Publication number: 20240223925Abstract: An optical path route design device (20A) includes a transmission/reception route selection unit (20), a candidate selection unit (21), an existence judgement unit (22), a maximum resource 3R selection unit (23), and a new 3R selection unit (24). The design device (20A) selects relay stations in which two transmission/reception end points are arranged, selects a route pair of an active system-0 route and a standby system-1 route, which connects the transmission/reception end points with each other and does not overlap each other, and a backup third route detouring from the route pair via one or more relay stations, and arranges a resource amount of predetermined wavelengths in a shared 3R which is on the third route and shared by a plurality of route pairs.Type: ApplicationFiled: June 14, 2021Publication date: July 4, 2024Inventors: Hiroki DATE, Takeshi SEKI, Takeshi KAWASAKI, Hideki Maeda
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Patent number: 12027208Abstract: A semiconductor memory device includes a memory cell array, a decoder circuit, a voltage supply circuit, and a control circuit. The voltage supply circuit is configured to generate a first voltage supplied to the decoder circuit, a second voltage supplied to a select gate line, and a third voltage supplied to a word line. The control circuit, during a read operation with respect to a memory cell transistor, starts a first control operation on the voltage supply circuit to boost the first voltage to a first target voltage, during the first control operation, starts a second control operation to boost the second voltage, and during the second control operation, starts a third control operation to boost the third voltage. During the first control operation, the first voltage is increased to and maintained at an intermediate voltage lower than the first target voltage for a certain period of time.Type: GrantFiled: February 24, 2022Date of Patent: July 2, 2024Assignee: Kioxia CorporationInventor: Hiroki Date
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Patent number: 12014773Abstract: A semiconductor storage device includes: a first memory cell and a second memory cell that are adjacent to each other and connected to each other in series; a first word line connected to the first memory cell; a second word line connected to the second memory cell; and a control circuit. The control circuit is configured to, in a first read operation to read a first bit stored in the first memory cell, apply a first voltage to the first word line, and then, apply a first read voltage lower than the first voltage, to the first word line, and apply a second voltage to the second word line, and then, apply a third voltage lower than the second voltage and higher than the first voltage, to the second word line. The third voltage is applied to the second word line after the first read voltage is applied to the first word line.Type: GrantFiled: August 5, 2022Date of Patent: June 18, 2024Assignee: KIOXIA CORPORATIONInventors: Hiroki Date, Takeshi Nakano
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Publication number: 20240096430Abstract: In one embodiment, a semiconductor storage device includes memory cell transistors, and a word line electrically connected to the memory cell transistors. The device further includes a voltage generator configured to generate a first voltage transferred to the word line, the voltage generator including a voltage divider configured to divide the first voltage with first and second resistance elements, the first or second resistance element being a variable resistance element that receives a first digital signal indicating a resistance value and is changeable to the resistance value. The device further includes a control unit configured to output the first digital signal, wherein the control unit outputs the first digital signal such that a theoretical waveform of the first voltage in boosting the first voltage in an erasing verifying operation is different from a theoretical waveform of the first voltage in boosting the first voltage in a reading operation.Type: ApplicationFiled: June 20, 2023Publication date: March 21, 2024Applicant: Kioxia CorporationInventor: Hiroki DATE
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Patent number: 11869597Abstract: A semiconductor storage device in an embodiment includes a plurality of planes each including a memory cell array, a voltage generation circuit configured to apply a first intermediate voltage to an adjacent word line adjacent to a selected word line in a former half of a program period and apply a second intermediate voltage higher than the first intermediate voltage to the adjacent word line in a latter half of the program period, a discharge circuit configured to feed a discharge current from the selected word line in a period corresponding to a period in which the second intermediate voltage is applied to the adjacent word line, and a control circuit configured to set a discharge characteristic of the discharge circuit according to a number of the planes.Type: GrantFiled: September 1, 2021Date of Patent: January 9, 2024Assignee: Kioxia CorporationInventors: Takeshi Nakano, Yuzuru Shibazaki, Hideyuki Kataoka, Junichi Sato, Hiroki Date
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Patent number: 11749348Abstract: A semiconductor storage device includes: a plurality of first memory cells; a word line connected to gates of the first memory cells; a voltage generation circuit configured to generate voltage to be supplied to the word line on the basis of a set value; and a control unit configured to execute a write sequence that includes a plurality of loops, each loop including a program operation to increase a threshold voltage of at least part of the first memory cells to thereby write data to the first memory cells and a verify operation to verify the data written to the first memory cells. The voltage generation circuit generates voltage to be supplied to the word line at start of the verify operation on the basis of a first set value, and the control unit adjusts the first set value in accordance with progress of the write sequence.Type: GrantFiled: August 26, 2021Date of Patent: September 5, 2023Assignee: Kioxia CorporationInventor: Hiroki Date
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Publication number: 20230088312Abstract: A semiconductor memory device includes a memory cell array, a decoder circuit, a voltage supply circuit, and a control circuit. The voltage supply circuit is configured to generate a first voltage supplied to the decoder circuit, a second voltage supplied to a select gate line, and a third voltage supplied to a word line. The control circuit, during a read operation with respect to a memory cell transistor, starts a first control operation on the voltage supply circuit to boost the first voltage to a first target voltage, during the first control operation, starts a second control operation to boost the second voltage, and during the second control operation, starts a third control operation to boost the third voltage. During the first control operation, the first voltage is increased to and maintained at an intermediate voltage lower than the first target voltage for a certain period of time.Type: ApplicationFiled: February 24, 2022Publication date: March 23, 2023Inventor: Hiroki DATE
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Publication number: 20220375517Abstract: A semiconductor storage device includes: a first memory cell and a second memory cell that are adjacent to each other and connected to each other in series; a first word line connected to the first memory cell; a second word line connected to the second memory cell; and a control circuit. The control circuit is configured to, in a first read operation to read a first bit stored in the first memory cell, apply a first voltage to the first word line, and then, apply a first read voltage lower than the first voltage, to the first word line, and apply a second voltage to the second word line, and then, apply a third voltage lower than the second voltage and higher than the first voltage, to the second word line. The third voltage is applied to the second word line after the first read voltage is applied to the first word line.Type: ApplicationFiled: August 5, 2022Publication date: November 24, 2022Applicant: Kioxia CorporationInventors: Hiroki DATE, Takeshi NAKANO
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Publication number: 20220301630Abstract: A semiconductor storage device in an embodiment includes a plurality of planes each including a memory cell array, a voltage generation circuit configured to apply a first intermediate voltage to an adjacent word line adjacent to a selected word line in a former half of a program period and apply a second intermediate voltage higher than the first intermediate voltage to the adjacent word line in a latter half of the program period, a discharge circuit configured to feed a discharge current from the selected word line in a period corresponding to a period in which the second intermediate voltage is applied to the adjacent word line, and a control circuit configured to set a discharge characteristic of the discharge circuit according to a number of the planes.Type: ApplicationFiled: September 1, 2021Publication date: September 22, 2022Applicant: Kioxia CorporationInventors: Takeshi NAKANO, Yuzuru SHIBAZAKI, Hideyuki KATAOKA, Junichi SATO, Hiroki DATE
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Publication number: 20220301627Abstract: A semiconductor storage device includes: a plurality of first memory cells; a word line connected to gates of the first memory cells; a voltage generation circuit configured to generate voltage to be supplied to the word line on the basis of a set value; and a control unit configured to execute a write sequence that includes a plurality of loops, each loop including a program operation to increase a threshold voltage of at least part of the first memory cells to thereby write data to the first memory cells and a verify operation to verify the data written to the first memory cells. The voltage generation circuit generates voltage to be supplied to the word line at start of the verify operation on the basis of a first set value, and the control unit adjusts the first set value in accordance with progress of the write sequence.Type: ApplicationFiled: August 26, 2021Publication date: September 22, 2022Applicant: Kioxia CorporationInventor: Hiroki DATE
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Patent number: 11450383Abstract: A semiconductor storage device includes: a first memory cell and a second memory cell that are adjacent to each other and connected to each other in series; a first word line connected to the first memory cell; a second word line connected to the second memory cell; and a control circuit. The control circuit is configured to, in a first read operation to read a first bit stored in the first memory cell, apply a first voltage to the first word line, and then, apply a first read voltage lower than the first voltage, to the first word line, and apply a second voltage to the second word line, and then, apply a third voltage lower than the second voltage and higher than the first voltage, to the second word line. The third voltage is applied to the second word line after the first read voltage is applied to the first word line.Type: GrantFiled: February 24, 2021Date of Patent: September 20, 2022Assignee: KIOXIA CORPORATIONInventors: Hiroki Date, Takeshi Nakano
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Publication number: 20220254393Abstract: In a semiconductor memory device, in a write operation performed to a memory cell transistor, a first voltage is applied to a first word line and a second voltage lower than the first voltage is applied to a second word line. When a stop command is received during the write operation, a third voltage lower than the second voltage is applied to the first and second word lines, thereafter a fourth voltage higher than the third voltage is applied to a first selection line, thereon or thereafter a fifth voltage higher than the fourth voltage is applied to the first and second word lines, thereafter a sixth voltage lower than the fourth voltage is applied to the first selection line, and thereafter a seventh voltage is applied to the first and second word lines.Type: ApplicationFiled: April 26, 2022Publication date: August 11, 2022Applicant: Kioxia CorporationInventor: Hiroki DATE
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Patent number: 11335388Abstract: In a semiconductor memory device, in a write operation performed to a memory cell transistor, a first voltage is applied to a first word line and a second voltage lower than the first voltage is applied to a second word line. When a command to stop is received during the write operation, a third voltage lower than the second voltage is applied to the first and second word lines, thereafter a fourth voltage higher than the third voltage is applied to a first selection line, thereon or thereafter a fifth voltage higher than the fourth voltage is applied to the first and second word lines, thereafter a sixth voltage lower than the fourth voltage is applied to the first selection line, and thereafter a seventh voltage is applied to the first and second word lines.Type: GrantFiled: April 30, 2020Date of Patent: May 17, 2022Assignee: KIOXIA CORPORATIONInventor: Hiroki Date
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Patent number: 11238941Abstract: A semiconductor memory device comprises a bit line and source line, a first memory cell and first and second transistors connected therebetween, a second memory cell and third and fourth transistors connected therebetween, and first through fifth wirings connected to the first and the second memory cells and gate electrodes of the first to the fourth transistors. At a first timing of a read operation, voltages of the first through third wirings are larger than voltages of the fourth and fifth wirings. At a second timing, voltages of the second and third wirings are larger than voltages of the fourth and fifth wirings. At a third timing, voltages of the fourth and fifth wirings are larger than their voltages at the second timing. At a fourth timing, voltages of the second and third wirings are larger than a voltage of the fourth wiring.Type: GrantFiled: August 31, 2020Date of Patent: February 1, 2022Assignee: Kioxia CorporationInventor: Hiroki Date
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Publication number: 20220020428Abstract: A semiconductor storage device includes: a first memory cell and a second memory cell that are adjacent to each other and connected to each other in series; a first word line connected to the first memory cell; a second word line connected to the second memory cell; and a control circuit. The control circuit is configured to, in a first read operation to read a first bit stored in the first memory cell, apply a first voltage to the first word line, and then, apply a first read voltage lower than the first voltage, to the first word line, and apply a second voltage to the second word line, and then, apply a third voltage lower than the second voltage and higher than the first voltage, to the second word line. The third voltage is applied to the second word line after the first read voltage is applied to the first word line.Type: ApplicationFiled: February 24, 2021Publication date: January 20, 2022Applicant: Kioxia CorporationInventors: Hiroki DATE, Takeshi NAKANO
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Publication number: 20210241837Abstract: A semiconductor memory device comprises a bit line and source line, a first memory cell and first and second transistors connected therebetween, a second memory cell and third and fourth transistors connected therebetween, and first through fifth wirings connected to the first and the second memory cells and gate electrodes of the first to the fourth transistors. At a first timing of a read operation, voltages of the first through third wirings are larger than voltages of the fourth and fifth wirings. At a second timing, voltages of the second and third wirings are larger than voltages of the fourth and fifth wirings. At a third timing, voltages of the fourth and fifth wirings are larger than their voltages at the second timing. At a fourth timing, voltages of the second and third wirings are larger than a voltage of the fourth wiring.Type: ApplicationFiled: August 31, 2020Publication date: August 5, 2021Applicant: Kioxia CorporationInventor: Hiroki DATE
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Patent number: 10984858Abstract: A semiconductor storage device includes: a voltage generation circuit configured to generate a read voltage to be supplied to a selected word line to which a read-target memory cell transistor is connected and a read-pass voltage to be supplied to an adjacent word line; a word line driver configured to, when the read voltage transitions, apply the read voltage to the selected word line with a first kick voltage amount and apply the read-pass voltage to the adjacent word line with a second kick voltage amount; and a control circuit configured to set each of the first kick voltage amount and the second kick voltage amount to a voltage corresponding to an amount of the transition.Type: GrantFiled: February 10, 2020Date of Patent: April 20, 2021Assignee: Kioxia CorporationInventor: Hiroki Date