Patents by Inventor Hiroshi Maejima
Hiroshi Maejima 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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Patent number: 10784275Abstract: A nonvolatile semiconductor storage device includes a memory cell array layer that includes a plurality of nonvolatile memory cells connected in series in a vertical direction above a semiconductor substrate, a plurality of word lines respectively connected to gates of the plurality of nonvolatile memory cells, a select gate transistor layer that is located above the memory cell array and includes at least first and second select gate transistors connected in series in the vertical direction and to the plurality of nonvolatile memory cells, and at least first and second select gate lines respectively connected to the at least first and second select gate transistors, and a control circuit configured to execute a read operation on the nonvolatile memory cells, such that during a read period of the read operation, signals having different voltage levels are supplied to the at least first and second select gate lines.Type: GrantFiled: August 26, 2019Date of Patent: September 22, 2020Assignee: Toshiba Memory CorporationInventor: Hiroshi Maejima
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Publication number: 20200295021Abstract: A nonvolatile semiconductor storage device includes a memory cell array layer that includes a plurality of nonvolatile memory cells connected in series in a vertical direction above a semiconductor substrate, a plurality of word lines respectively connected to gates of the plurality of nonvolatile memory cells, a select gate transistor layer that is located above the memory cell array and includes at least first and second select gate transistors connected in series in the vertical direction and to the plurality of nonvolatile memory cells, and at least first and second select gate lines respectively connected to the at least first and second select gate transistors, and a control circuit configured to execute a read operation on the nonvolatile memory cells, such that during a read period of the read operation, signals having different voltage levels are supplied to the at least first and second select gate lines.Type: ApplicationFiled: August 26, 2019Publication date: September 17, 2020Inventor: Hiroshi MAEJIMA
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Publication number: 20200294607Abstract: A memory device includes first and second memory strings, first and second word lines and a controller. The first memory string includes first and second memory cells, a first select transistor, a second select transistor, and a third select transistor between the first and second memory cells. The second memory string includes third and fourth memory cells, a fourth select transistor above the third memory cell, a fifth select transistor below the fourth memory cell, and a sixth select transistor between the third and fourth memory cells. The first word line is electrically connected to gates of the first and third memory cells. The second word line is electrically connected to gates of the second and fourth memory cells. The controller is configured to execute a read operation on one of the memory cells, the read operation including a first phase and a second phase after the first phase.Type: ApplicationFiled: June 3, 2020Publication date: September 17, 2020Inventor: Hiroshi MAEJIMA
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Publication number: 20200286560Abstract: A semiconductor memory device includes a memory cell array having memory strings that include memory cells and first and second selection transistors. During a read operation, a controller applies a first voltage higher than ground to a source line, and a second voltage to a first and second selection gate lines that are connected to a selected memory string. The second voltage is also applied to the first selection gate lines connected to non-selected memory strings during a first period of the read operation. A third voltage higher than ground and lower than the second voltage is applied to the first selection gate lines connected to non-selected memory strings during a second period of the read operation subsequent to the first period.Type: ApplicationFiled: May 26, 2020Publication date: September 10, 2020Inventor: Hiroshi MAEJIMA
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Publication number: 20200234766Abstract: A semiconductor storage device includes word lines extending in first and second directions, and separated from each other in a third direction, sense amplifier circuits that partially overlap the word lines in the third direction, memory strings intersecting the word lines and extending in the third direction, memory-side bit lines extending in the first direction, separated from each other in the second direction, and including first and second adjacent memory-side bit lines, circuit-side bit lines between the word lines and the sense amplifier circuits and partially overlapping the respective memory-side bit lines in the third direction, and contact plugs extending in the third direction and respectively connecting the memory-side bit lines and the circuit-side bit lines. The contact plugs include first and second contract plugs that are electrically connected to the first and second memory-side bit lines, respectively, and are not aligned along the first or second direction.Type: ApplicationFiled: April 7, 2020Publication date: July 23, 2020Inventor: Hiroshi MAEJIMA
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Memory in which the channel potential of a memory cell in a non-selected NAND cell unit is increased
Patent number: 10720216Abstract: A three dimensional stacked nonvolatile semiconductor memory according to an example of the present invention includes a memory cell array comprised of first and second blocks. The first block has a first cell unit which includes a memory cell to be programmed and a second cell unit which does not include a memory cell to be programmed, and programming is executed by applying a program potential or a transfer potential to word lines in the first block after the initial potential of channels of the memory cells in the first and second cell units is set to a plus potential. In the programming, the program potential and the transfer potential are not applied to word lines in the second block.Type: GrantFiled: January 18, 2019Date of Patent: July 21, 2020Assignee: Toshiba Memory CorporationInventor: Hiroshi Maejima -
Patent number: 10706931Abstract: A semiconductor memory device includes a memory cell array having memory strings that include memory cells and first and second selection transistors. During a read operation, a controller applies a first voltage higher than ground to a source line, and a second voltage to a first and second selection gate lines that are connected to a selected memory string. The second voltage is also applied to the first selection gate lines connected to non-selected memory strings during a first period of the read operation. A third voltage higher than ground and lower than the second voltage is applied to the first selection gate lines connected to non-selected memory strings during a second period of the read operation subsequent to the first period.Type: GrantFiled: August 14, 2019Date of Patent: July 7, 2020Assignee: TOSHIBA MEMORY CORPORATIONInventor: Hiroshi Maejima
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Patent number: 10699792Abstract: A memory device includes first and second memory strings, first and second word lines and a controller. The first memory string includes first and second memory cells, a first select transistor, a second select transistor, and a third select transistor between the first and second memory cells. The second memory string includes third and fourth memory cells, a fourth select transistor above the third memory cell, a fifth select transistor below the fourth memory cell, and a sixth select transistor between the third and fourth memory cells. The first word line is electrically connected to gates of the first and third memory cells. The second word line is electrically connected to gates of the second and fourth memory cells. The controller is configured to execute a read operation on one of the memory cells, the read operation including a first phase and a second phase after the first phase.Type: GrantFiled: December 5, 2018Date of Patent: June 30, 2020Assignee: TOSHIBA MEMORY CORPORATIONInventor: Hiroshi Maejima
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Publication number: 20200194088Abstract: A semiconductor memory device includes a first memory cell which is capable of being set to any one of at least eight threshold voltages, a first bit line connected to the first memory cell, a word line connected to a gate of the first memory cell, a sense amplifier connected to the first bit line, wherein the sense amplifier has at least four data latch circuits, and an extra data latch circuit connected to the sense amplifier through a data bus. A verification operation for verifying the threshold voltage of the first memory cell is performed after a programming operation is performed on the first memory cell, and the verification operation includes seven verification operations during which the four data latch circuits, but not the extra data latch circuit, are accessed.Type: ApplicationFiled: February 25, 2020Publication date: June 18, 2020Inventors: Hiroshi MAEJIMA, Noboru SHIBATA
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Publication number: 20200183593Abstract: A semiconductor storage device includes memory cells, select transistors, memory strings, first and second blocks, word lines, and select gate lines. In the memory string, the current paths of plural memory cells are connected in series. When data are written in a first block, after a select gate line connected to the gate of a select transistor of one of the memory strings in the first block is selected, the data are sequentially written in the memory cells in the memory string connected to the selected select gate line. When data are written in the second block, after a word line connected to the control gates of memory cells of different memory strings in the second block is selected, the data are sequentially written in the memory cells of the different memory strings in the second block which have their control gates connected to the selected word line.Type: ApplicationFiled: February 12, 2020Publication date: June 11, 2020Inventor: Hiroshi MAEJIMA
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Publication number: 20200176061Abstract: According to one embodiment, a semiconductor memory includes: a first bit line; a first select transistor having a first terminal connected to the first bit line; a first memory cell connected to a second terminal of the first select transistor; a circuit connected to the first bit line and applying an erase voltage to be applied to the first memory cell to the bit line via the first terminal and the second terminal; and a diode connected to the first bit line and the first circuit.Type: ApplicationFiled: September 11, 2019Publication date: June 4, 2020Applicant: Toshiba Memory CorporationInventors: Hiroshi MAEJIMA, Katsuaki ISOBE, Naohito MOROZUMO, Go SHIKATA, Susumu FUJIMURA
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Patent number: 10672483Abstract: A memory device includes a memory cell array with memory strings including a first and second select transistor and memory cells between the first and second select transistors. Each memory string has a bit line connected thereto. A different word line is connected to each of the memory cells of a memory strings. A control circuit is configured to execute a first read operation in which data is read at the same time from memory cells connected to all the bit lines and a second read operation in which data is read from memory cells connected to a first subset of bit lines and a shield voltage is applied to a second subset of bit lines in the plurality of bit lines. The controller selects the first or second read operation for execution according to the number of read voltage levels required for determining data in the memory cells.Type: GrantFiled: August 24, 2018Date of Patent: June 2, 2020Assignee: TOSHIBA MEMORY CORPORATIONInventor: Hiroshi Maejima
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Patent number: 10672487Abstract: A semiconductor memory device includes first and second memory cells, each of which includes a charge storage layer, a first bit line that is connected to the first memory cell, and a second bit line that is connected to the second memory cell. A writing operation includes multiple loops of a programming operation and a verification operation, and first data is written in the first memory cell, and second data different from the first data is written in the second memory cell through the writing operation. In a first loop of the writing operation, a first voltage is applied to the first bit line and the second bit line is maintained in an electrically floating state during the programming operation, and a verification operation relating to the second data is not performed and a verification operation relating to the first data is performed.Type: GrantFiled: July 1, 2019Date of Patent: June 2, 2020Assignee: Toshiba Memory CorporationInventors: Hiroshi Maejima, Koji Hosono, Tadashi Yasufuku, Noboru Shibata
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Patent number: 10643702Abstract: A semiconductor storage device includes word lines extending in first and second directions, and separated from each other in a third direction, sense amplifier circuits that partially overlap the word lines in the third direction, memory strings intersecting the word lines and extending in the third direction, memory-side bit lines extending in the first direction, separated from each other in the second direction, and including first and second adjacent memory-side bit lines, circuit-side bit lines between the word lines and the sense amplifier circuits and partially overlapping the respective memory-side bit lines in the third direction, and contact plugs extending in the third direction and respectively connecting the memory-side bit lines and the circuit-side bit lines. The contact plugs include first and second contract plugs that are electrically connected to the first and second memory-side bit lines, respectively, and are not aligned along the first or second direction.Type: GrantFiled: April 22, 2019Date of Patent: May 5, 2020Assignee: TOSHIBA MEMORY CORPORATIONInventor: Hiroshi Maejima
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Publication number: 20200126628Abstract: A semiconductor storage device includes first and second memory cell transistors at opposite sides of a first semiconductor body, third and fourth memory cell transistors at opposite sides of a second semiconductor body, a first word line connected to gates of the first and third memory cell transistors, a second word line connected to gates of the second and fourth memory cell transistors, and a controller. During a program operation on the third memory cell transistor, the controller determines a program voltage on the basis of a first number of loops determined during the write operation performed on the first memory cell transistor, and during a program operation on the fourth memory cell transistor, the controller determines a program voltage on the basis of a second number of loops determined during the write operation performed on the second memory cell transistor.Type: ApplicationFiled: August 26, 2019Publication date: April 23, 2020Inventor: Hiroshi MAEJIMA
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Patent number: 10614900Abstract: A semiconductor memory device includes a first memory cell which is capable of being set to any one of at least eight threshold voltages, a first bit line connected to the first memory cell, a word line connected to a gate of the first memory cell, a sense amplifier connected to the first bit line, wherein the sense amplifier has at least four data latch circuits, and an extra data latch circuit connected to the sense amplifier through a data bus. A verification operation for verifying the threshold voltage of the first memory cell is performed after a programming operation is performed on the first memory cell, and the verification operation includes seven verification operations during which the four data latch circuits, but not the extra data latch circuit, are accessed.Type: GrantFiled: May 13, 2019Date of Patent: April 7, 2020Assignee: TOSHIBA MEMORY CORPORATIONInventors: Hiroshi Maejima, Noboru Shibata
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Publication number: 20200091175Abstract: According to one embodiment, a memory system includes: a semiconductor memory device; and a controller. The semiconductor memory device includes: first interconnection layers; second interconnection layers; a semiconductor pillar. The semiconductor memory device executes an operation in a first mode or in a second mode. In the first mode, the device selects a third interconnection layer among the first interconnection layers independently with a fourth interconnection layer among the second interconnection layers. In the second mode, the device selects a fifth interconnection layer among the first interconnection layers and sixth interconnection layer among the second interconnection layers in a batch. The controller sends an instruction to the device to execute the operation in the first mode or the second mode.Type: ApplicationFiled: February 25, 2019Publication date: March 19, 2020Applicant: Toshiba Memory CorporationInventor: Hiroshi MAEJIMA
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Patent number: 10564860Abstract: A semiconductor storage device includes memory cells, select transistors, memory strings, first and second blocks, word lines, and select gate lines. In the memory string, the current paths of plural memory cells are connected in series. When data are written in a first block, after a select gate line connected to the gate of a select transistor of one of the memory strings in the first block is selected, the data are sequentially written in the memory cells in the memory string connected to the selected select gate line. When data are written in the second block, after a word line connected to the control gates of memory cells of different memory strings in the second block is selected, the data are sequentially written in the memory cells of the different memory strings in the second block which have their control gates connected to the selected word line.Type: GrantFiled: October 11, 2018Date of Patent: February 18, 2020Assignee: Toshiba Memory CorporationInventor: Hiroshi Maejima
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Publication number: 20190392905Abstract: According to one embodiment, a semiconductor memory device includes first and second memory cells; a first word line connected to the first and second memory cells; a first bit line connected to the first memory cell; a second bit line connected to the second memory cell; a first sense amplifier connected to the first bit line; a second sense amplifier connected to the second bit line; a voltage generation circuit; and a first row decoder which supplies a voltage to the first word line.Type: ApplicationFiled: June 3, 2019Publication date: December 26, 2019Applicant: Toshiba Memory CorporationInventors: Takeshi Hioka, Tsukasa Kobayashi, Koji Kato, Yuki Shimizu, Hiroshi Maejima
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Publication number: 20190371403Abstract: A semiconductor memory device includes a memory cell array having memory strings that include memory cells and first and second selection transistors. During a read operation, a controller applies a first voltage higher than ground to a source line, and a second voltage to a first and second selection gate lines that are connected to a selected memory string. The second voltage is also applied to the first selection gate lines connected to non-selected memory strings during a first period of the read operation. A third voltage higher than ground and lower than the second voltage is applied to the first selection gate lines connected to non-selected memory strings during a second period of the read operation subsequent to the first period.Type: ApplicationFiled: August 14, 2019Publication date: December 5, 2019Inventor: Hiroshi MAEJIMA