Patents by Inventor Rieko FUNATSUKI
Rieko FUNATSUKI 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: 11967371Abstract: A semiconductor memory device includes i first word lines connected to the i first memory cells, i second word lines connected to the i second memory cells, a driver capable of supplying voltage to each of the i first word lines and each of the i second word lines, and a logic control circuit controlling both a write operation including a verify operation and a read operation including a verify operation. In the semiconductor memory device, when an order of performing a sense operation for determining whether or not a threshold voltage of the k-th first memory cell has reached a j-th threshold voltage in the verify operation is different from that of in the read operation, a voltage applied to the k-th first word line in the verify operation is different from a voltage applied to the k-th first word line in the read operation.Type: GrantFiled: June 10, 2022Date of Patent: April 23, 2024Assignee: Kioxia CorporationInventors: Rieko Funatsuki, Takashi Maeda, Hidehiro Shiga
-
Publication number: 20240096413Abstract: A control circuit of a semiconductor memory device performs a write operation on a memory cell transistor of the semiconductor memory device by performing a first pulse application operation of lowering a threshold voltage of the memory cell transistor, a precharge operation, and then a second pulse application operation. In the precharge operation, in a state in which first and second select transistors connected to the memory cell transistor are turned on, a bit line connected to the memory cell transistor is charged by applying a ground voltage to a word line connected to a gate of the memory cell transistor and applying a voltage higher than the ground voltage to a source line. In the second pulse application operation, in a state in which the first select transistor is turned on and the second select transistor is turned off, a program voltage is applied to the word line.Type: ApplicationFiled: March 2, 2023Publication date: March 21, 2024Inventors: Natsuki SAKAGUCHI, Takashi MAEDA, Rieko FUNATSUKI, Hidehiro SHIGA
-
Publication number: 20240071477Abstract: A memory system for speeding up a read operation in the memory system includes a first pillar, a first string including a first transistor and a first memory cell, a second string including a second transistor and a second memory cell, a first bit line, a first gate line, a first word line, a second gate line, a second word line and a control circuit. When the control circuit executes a read operation with respect to the first memory cell, the control circuit is configured to apply a read voltage to the first word line, apply a voltage turning off the second memory cell regardless of an electric charge stored in the second memory cell to the second word line, apply a voltage turning on the first transistor to the first gate line, and apply a voltage turning on the second transistor to the second gate line.Type: ApplicationFiled: November 2, 2023Publication date: February 29, 2024Applicant: Kioxia CorporationInventors: Kazutaka IKEGAMI, Rieko FUNATSUKI, Nobuyuki MOMO, Hidehiro SHIGA
-
Publication number: 20240062822Abstract: A semiconductor memory device includes a first to eighth memory cell groups arranged along a first direction, a first word line extending in the first direction and a first to an eighth sense amplifier groups configured to be capable of supplying voltages to the first to the eighth memory cell groups, respectively. Each of the first to the eighth memory cell groups includes a plurality of memory cells and a plurality of bit lines each connected to the plurality of memory cells. In a write operation of supplying a program voltage to the first word line, the first sense amplifier group supplies a first voltage to the bit line connected to a write target memory cell of the first memory cell group, and the second sense amplifier group supplies a second voltage to the bit line connected to a write target memory cell of the second memory cell group.Type: ApplicationFiled: November 2, 2023Publication date: February 22, 2024Applicant: Kioxia CorporationInventors: Rieko FUNATSUKI, Takashi MAEDA
-
Publication number: 20230413584Abstract: A memory device includes: a first interconnect; a second interconnect; a first string and a second string whose first ends are coupled to the first interconnect; a third string and a fourth string whose second ends are coupled to the second interconnect; a third interconnect; and driver. The third interconnect is coupled to second ends of the first and second strings and to first ends of the third and fourth strings. Each of the first, second, third, and fourth strings includes a first switch element and a memory cell coupled in series. The memory cell includes a second switch element and a resistance change element coupled in parallel. The third interconnect is coupled to the driver via the first interconnect or the second interconnect.Type: ApplicationFiled: August 8, 2023Publication date: December 21, 2023Applicant: Kioxia CorporationInventors: Takahiko IIZUKA, Daisaburo TAKASHIMA, Ryu OGIWARA, Rieko FUNATSUKI, Yoshiki KAMATA, Misako MOROTA, Yoshiaki ASAO, Yukihiro NOMURA
-
Patent number: 11769554Abstract: A semiconductor memory device of embodiments includes: a substrate; a memory pillar; first to sixth conductive layers provided above the substrate; first to sixth memory cells formed between the first to sixth conductive layers and the memory pillar, respectively; and a control circuit. The control circuit applies a first voltage to the first, second, a sixth conductive layer and applies a second voltage to the third, fifth conductive layer, then applies a third voltage to the first conductive layer, applies a fourth voltage to the sixth conductive layer, and applies a fifth voltage to the second conductive layer, and then applies a sixth voltage to the first conductive layer, applies a seventh voltage to the sixth conductive layer, and applies an eighth voltage lower than the fifth voltage to the second conductive layer.Type: GrantFiled: September 13, 2021Date of Patent: September 26, 2023Assignee: Kioxia CorporationInventors: Kyosuke Sano, Kazutaka Ikegami, Takashi Maeda, Rieko Funatsuki
-
Publication number: 20230297245Abstract: A semiconductor memory device includes a semiconductor pillar including first and second memory cells electrically connected in series and formed on opposite sides of the semiconductor pillar, first word lines connected to the first memory cells, respectively, and second word lines connected to the second memory cells, respectively. A verify operation includes a channel clean operation for supplying a reference voltage to a semiconductor channel shared by the first and second memory cells followed by at least first and second sense operation for determining whether a threshold voltage of a target memory cell has reached first and second threshold voltage states, respectively, then a second channel clean operation for supplying the reference voltage to the semiconductor channel, and then at least a third sense operation for determining whether the threshold voltage of the target memory cell has reached a third threshold voltage state.Type: ApplicationFiled: August 31, 2022Publication date: September 21, 2023Inventors: Rieko FUNATSUKI, Takashi MAEDA, Sumiko DOMAE, Kazutaka IKEGAMI
-
Patent number: 11765916Abstract: A memory device includes: a first interconnect; a second interconnect; a first string and a second string whose first ends are coupled to the first interconnect; a third string and a fourth string whose second ends are coupled to the second interconnect; a third interconnect; and driver. The third interconnect is coupled to second ends of the first and second strings and to first ends of the third and fourth strings. Each of the first, second, third, and fourth strings includes a first switch element and a memory cell coupled in series. The memory cell includes a second switch element and a resistance change element coupled in parallel. The third interconnect is coupled to the driver via the first interconnect or the second interconnect.Type: GrantFiled: June 16, 2021Date of Patent: September 19, 2023Assignee: Kioxia CorporationInventors: Takahiko Iizuka, Daisaburo Takashima, Ryu Ogiwara, Rieko Funatsuki, Yoshiki Kamata, Misako Morota, Yoshiaki Asao, Yukihiro Nomura
-
Patent number: 11715527Abstract: A semiconductor storage device includes a semiconductor pillar, a first string having first memory cells connected in series, first word lines connected to the first memory cells, a second string having second memory cells connected in series, and second word lines connected to the second memory cells. Each of the first memory cells faces, and shares a channel in the semiconductor pillar with, one of the second memory cells. When reading data of the k-th first memory cell, a voltage of the first word line connected to the k-th first memory cell reaches a first voltage at a first timing, and a voltage of the second word line connected to at least one of the second memory cells other than the k-th second memory cell in the second string facing the k-th first memory cell reaches the first voltage at a second timing that is later than the first timing.Type: GrantFiled: August 26, 2021Date of Patent: August 1, 2023Assignee: Kioxia CorporationInventors: Kazutaka Ikegami, Hidehiro Shiga, Takashi Maeda, Rieko Funatsuki, Takayuki Miyazaki
-
Patent number: 11715534Abstract: A semiconductor storage device includes a memory cell array including a plurality of memory strings, each connected between one of a plurality of bit lines and a source line and includes a first select transistor, a second select transistor, and memory cell transistors that are connected in series between the first select transistor and the second select transistor, and a plurality of word lines respectively connected to gates of the memory cell transistors in each memory string. A threshold voltage of the memory cell transistor is increased when a voltage that is applied to the word line connected to the gate thereof is lower than a voltage of a channel thereof. In the erase operation, data stored in the memory cell transistors connected to a selected one of the word lines are erased while data stored in the memory cell transistors not connected to the selected word line are not erased.Type: GrantFiled: August 27, 2021Date of Patent: August 1, 2023Assignee: Kioxia CorporationInventors: Rieko Funatsuki, Takashi Maeda, Reiko Sumi, Reika Tanaka, Masumi Saitoh
-
Publication number: 20230197148Abstract: A semiconductor memory device includes i first word lines connected to the i first memory cells, i second word lines connected to the i second memory cells, a driver capable of supplying voltage to each of the i first word lines and each of the i second word lines, and a logic control circuit controlling both a write operation including a verify operation and a read operation including a verify operation. In the semiconductor memory device, when an order of performing a sense operation for determining whether or not a threshold voltage of the k-th first memory cell has reached a j-th threshold voltage in the verify operation is different from that of in the read operation, a voltage applied to the k-th first word line in the verify operation is different from a voltage applied to the k-th first word line in the read operation.Type: ApplicationFiled: June 10, 2022Publication date: June 22, 2023Applicant: Kioxia CorporationInventors: Rieko FUNATSUKI, Takashi MAEDA, Hidehiro SHIGA
-
Publication number: 20220301636Abstract: A semiconductor memory device of embodiments includes: a substrate; a memory pillar; first to sixth conductive layers provided above the substrate; first to sixth memory cells formed between the first to sixth conductive layers and the memory pillar, respectively; and a control circuit. The control circuit applies a first voltage to the first, second, a sixth conductive layer and applies a second voltage to the third, fifth conductive layer, then applies a third voltage to the first conductive layer, applies a fourth voltage to the sixth conductive layer, and applies a fifth voltage to the second conductive layer, and then applies a sixth voltage to the first conductive layer, applies a seventh voltage to the sixth conductive layer, and applies an eighth voltage lower than the fifth voltage to the second conductive layer.Type: ApplicationFiled: September 13, 2021Publication date: September 22, 2022Applicant: Kioxia CorporationInventors: Kyosuke SANO, Kazutaka IKEGAMI, Takashi MAEDA, Rieko FUNATSUKI
-
Publication number: 20220301643Abstract: A semiconductor storage device includes a memory cell array including a plurality of memory strings, each connected between one of a plurality of bit lines and a source line and includes a first select transistor, a second select transistor, and memory cell transistors that are connected in series between the first select transistor and the second select transistor, and a plurality of word lines respectively connected to gates of the memory cell transistors in each memory string. A threshold voltage of the memory cell transistor is increased when a voltage that is applied to the word line connected to the gate thereof is lower than a voltage of a channel thereof. In the erase operation, data stored in the memory cell transistors connected to a selected one of the word lines are erased while data stored in the memory cell transistors not connected to the selected word line are not erased.Type: ApplicationFiled: August 27, 2021Publication date: September 22, 2022Inventors: Rieko FUNATSUKI, Takashi MAEDA, Reiko SUMI, Reika TANAKA, Masumi SAITOH
-
Publication number: 20220180942Abstract: A semiconductor storage device includes a semiconductor pillar, a first string having first memory cells connected in series, first word lines connected to the first memory cells, a second string having second memory cells connected in series, and second word lines connected to the second memory cells. Each of the first memory cells faces, and shares a channel in the semiconductor pillar with, one of the second memory cells. When reading data of the k-th first memory cell, a voltage of the first word line connected to the k-th first memory cell reaches a first voltage at a first timing, and a voltage of the second word line connected to at least one of the second memory cells other than the k-th second memory cell in the second string facing the k-th first memory cell reaches the first voltage at a second timing that is later than the first timing.Type: ApplicationFiled: August 26, 2021Publication date: June 9, 2022Inventors: Kazutaka IKEGAMI, Hidehiro SHIGA, Takashi MAEDA, Rieko FUNATSUKI, Takayuki MIYAZAKI
-
Publication number: 20220093152Abstract: According to one embodiment, a memory device includes: a third layer between first and a second layers above a substrate; a pillar being adjacent to the first to third layers and including a ferroelectric layer; a memory cell between the third layer and the pillar; and a circuit which executes a first operation for a programming, a second operation for an erasing using a first voltage, and a third operation of applying a second voltage between the third layer and the pillar. The first voltage has a first potential difference, the second voltage has a second potential difference smaller than the first potential difference. A potential of the third conductive layer is lower than a potential of the pillar in each of the first and second voltages. The third operation is executed between the first operation and the second operation.Type: ApplicationFiled: March 15, 2021Publication date: March 24, 2022Applicant: Kioxia CorporationInventors: Reika TANAKA, Masumi SAITOH, Takashi MAEDA, Rieko FUNATSUKI, Hidehiro SHIGA
-
Patent number: 11282578Abstract: A semiconductor storage apparatus includes a memory cell array including a plurality of memory string structures each including a pair of memory string formation sections each formed by a channel formation film and a charge storage film and including a select gate transistor and a plurality of memory cell transistors connected in series and a partial conductive layer configured to electrically connect the memory string formation sections. During a reading operation of a memory cell transistor, at least one of the plurality of memory cell transistors and the select gate transistor belonging to the memory string formation section is turned off such that a channel of a memory cell transistor is fixed to a potential of a source line or a potential of bit lines.Type: GrantFiled: June 19, 2020Date of Patent: March 22, 2022Assignee: Kioxia CorporationInventors: Rieko Funatsuki, Takahiko Hara, Takashi Maeda
-
Patent number: 11282559Abstract: According to one embodiment, a memory device includes: a third layer between first and a second layers above a substrate; a pillar being adjacent to the first to third layers and including a ferroelectric layer; a memory cell between the third layer and the pillar; and a circuit which executes a first operation for a programming, a second operation for an erasing using a first voltage, and a third operation of applying a second voltage between the third layer and the pillar. The first voltage has a first potential difference, the second voltage has a second potential difference smaller than the first potential difference. A potential of the third conductive layer is lower than a potential of the pillar in each of the first and second voltages. The third operation is executed between the first operation and the second operation.Type: GrantFiled: March 15, 2021Date of Patent: March 22, 2022Assignee: Kioxia CorporationInventors: Reika Tanaka, Masumi Saitoh, Takashi Maeda, Rieko Funatsuki, Hidehiro Shiga
-
Publication number: 20210399049Abstract: A memory device includes: a first interconnect; a second interconnect; a first string and a second string whose first ends are coupled to the first interconnect; a third string and a fourth string whose second ends are coupled to the second interconnect; a third interconnect; and driver. The third interconnect is coupled to second ends of the first and second strings and to first ends of the third and fourth strings. Each of the first, second, third, and fourth strings includes a first switch element and a memory cell coupled in series. The memory cell includes a second switch element and a resistance change element coupled in parallel. The third interconnect is coupled to the driver via the first interconnect or the second interconnect.Type: ApplicationFiled: June 16, 2021Publication date: December 23, 2021Applicant: Kioxia CorporationInventors: Takahiko IIZUKA, Daisaburo TAKASHIMA, Ryu OGIWARA, Rieko FUNATSUKI, Yoshiki KAMATA, Misako MOROTA, Yoshiaki ASAO, Yukihiro NOMURA
-
Patent number: 11200951Abstract: According to one embodiment, a semiconductor memory device includes a plurality of memory cells; a first circuit configured to convert first data into second data relating to an order of thresholds of the memory cells; and a second circuit configured to perform a write operation on the memory cells based on the second data.Type: GrantFiled: September 5, 2019Date of Patent: December 14, 2021Assignee: TOSHIBA MEMORY CORPORATIONInventors: Rieko Funatsuki, Takahiko Sasaki, Tomonori Kurosawa
-
Patent number: 11049573Abstract: A semiconductor storage device includes a first memory cell and a second memory cell which are connected to each other in series, a first word line which is connected to the first memory cell, a second word line which is connected to the second memory cell, and a control circuit. The control circuit is configured to charge a first node while applying a second voltage to the second word line and a first voltage to the first word line, to charge a second node on the basis of a voltage of the charged first node, to discharge the second node while applying the second voltage to the second word line and a third voltage to the first word line, and to read data from the first memory cell on the basis of voltages of the charged and discharged second node.Type: GrantFiled: February 26, 2020Date of Patent: June 29, 2021Assignee: KIOXIA CORPORATIONInventors: Rieko Funatsuki, Takashi Maeda, Hidehiro Shiga, Hiroshi Maejima