Kabushiki Kaisha Toshiba

Kioxia Corporation

Toshiba Memory Corporation

National Institute of Advanced Industrial Science and Technology

Kazutaka Ikegami

Shinobu Fujita

Hiroki Noguchi

Keiko Abe

Naoharu Shimomura

Tomoaki Inokuchi

Kumiko Nomura

Hiroaki Yoda

Katsuhiko Koui

Takashi Maeda

Hideyuki Sugiyama

Yuuzo Kamiguchi

Shinichi Yasuda

Tetsufumi Tanamoto

Rieko Funatsuki

Satoshi Shirotori

Hidehiro Shiga

Satoshi Takaya

Susumu Takeda

Yuichi Ohsawa

Atsuhiro Kinoshita

Daisuke Hagishima

Reiko Sumi

Kyosuke Sano

Yoshiaki Saito

Takayuki Miyazaki

Yoshifumi Nishi

Chikayoshi Kamata

Shinji Yuasa

Daisuke Saida

Masato Oda

Mari Matsumoto

Kazuya Matsuzawa

Saori Kashiwada

Megumi Yakabe

Nobuyuki Momo

Takayuki Nozaki

Sumiko Domae

Yoshishige Suzuki

Hiroaki Maekawa

Yoichi Shiota

Takurou Ikeura

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.

Memory system

A memory system according to an embodiment includes a first bit line, a source line, a first word line, a second word line, a first memory pillar and a control circuit. The control circuit performs a first verify operation to first and second memory cells, a second verify operation to the first memory cell, a third verify operation to the second memory cell and a write operation or a read operation with a lower voltage in accordance with a request from an external device.

Memory system with verify operations of odd and even word lines

A semiconductor memory device includes a first memory pillar and a sequencer. The first memory pillar is sandwiched between a first word line and a second word line, sandwiched between a third word line and a fourth word line, sandwiched between a fifth word line and a sixth word line, includes a first memory cell facing the first word line, a second memory cell facing the second word line, a third memory cell facing the third word line, a fourth memory cell facing the fourth word line, a fifth memory cell facing the fifth word line and a sixth memory cell facing the sixth word line. The sequencer executes an erase operation on the first to sixth memory cells to enable execution of a primary write operation for the first memory cell and a primary write operation for the second memory cell at different timings.

Semiconductor memory device

A semiconductor memory device comprises: a semiconductor layer extending in a first direction; a first and second conductive layer facing the semiconductor layer from one side and the other side in a second direction; and a charge storage layer comprising portions provided between the semiconductor layer and first conductive layer and between the semiconductor layer and second conductive layer. The semiconductor memory device is configured to execute erase operation, first write operation, and second write operation. In the first write operation, the first and second conductive layers are applied with first program voltage. In the second write operation, the first conductive layer is applied with second program voltage, and second conductive layer is applied with second voltage lower than the second program voltage. The second write operation is executed after execution of the erase operation and before execution of the first write operation.

Semiconductor memory device and method of controlling the same

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.

A semiconductor storage device includes a first word line, a second word line provided in the same layer with the first word line and configured to be controlled independently from the first word line, a plurality of memory pillars between the first word line and the second word line, each of the plurality of memory pillars including a first memory cell facing to the first word line and a second memory cell facing to the second word line, the plurality of memory pillars being arranged in a first direction and a second direction intersecting to the first direction and a control circuit. The control circuit is configured to perform a write operation to the second memory cell included in the plurality of memory pillars after performing a write operation to the first memory cell included in each of the plurality of memory pillars.

Semiconductor storage device having reduced threshold distribution interference

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.

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.

Semiconductor storage device having first and second memory strings formed on opposite sides of the same pillar and method of performing a read operation therein

According to one embodiment, an arithmetic device includes a first computational circuit including a first string, the first string having a first magnetoresistive effect element on a first conducting layer; a second computational circuit including a second strings, the second string having second magnetoresistive effect element on a second conducting layer; a third computational circuit executing computational processing using a first signal from the first computational circuit and a second signal from the second computational circuit; and a control circuit. The control circuit sets a condition on write operations with respect to at least one of the first and second magnetoresistive effect elements, based on information related to write error in at least one of the first and second magnetoresistive effect elements.

Arithmetic device having magnetoresistive effect elements

A magnetic device includes: a first conductive layer; a first magnetoresistive effect element disposed on the first conductive layer and including a first control terminal; and a first circuit configured to supply a first current in a first direction into the first conductive layer and apply a first control voltage to the first control terminal of the first magnetoresistive effect element, wherein in a case in which the first current is supplied to the first conductive layer, the first magnetoresistive effect element holds a value corresponding to a logical disjunction between a first value of first data in the first magnetoresistive effect element and a second value of the first control voltage corresponding to second data.

Magnetic device storing first and second values

According to one embodiment, a magnetic memory apparatus includes a first stacked body and a controller. The first stacked body includes a first magnetic layer, a first counter magnetic layer, and a first intermediate layer placed between the first magnetic layer and the first counter magnetic layer. The first intermediate layer is nonmagnetic. The controller is electrically connected to the first magnetic layer and the first counter magnetic layer. The controller is configured to perform a first operation of supplying first pulse current to the first stacked body. The first pulse current includes a first constant-current period. A first electrical resistance value of the first stacked body before the supply of the first pulse current is different from a second electrical resistance value of the first stacked body after the supply of the first pulse current.

Magnetic memory apparatus

According to one embodiment, a magnetic memory device includes a conductive member, a first element portion, and a controller. The conductive member includes a first portion, a second portion, and a third portion between the first portion and the second portion. The first element portion includes a first element, a first interconnect, and a first circuit. The first element includes a first magnetic layer, a first counter magnetic layer, and a first nonmagnetic layer. The first counter magnetic layer is provided between the third portion and the first magnetic layer. The first nonmagnetic layer is provided between the first counter magnetic layer and the first magnetic layer. The first interconnect is electrically connected to the first magnetic layer. The first circuit is electrically connected to the first interconnect. The first circuit includes a first switch, a first capacitance element, a first parallel switch, and a first parallel capacitance element.

Magnetic memory device

According to one embodiment, a magnetic memory includes: a memory area; a first memory unit disposed in the memory area and including h first magnetoresistive effect elements arrayed on a first conductive layer; and a first circuit configured to receive i-bit first data, convert the first data into j-bit (j=h) second data, and write the second data in the first memory unit. The second data includes m first values and (j&#x2212;m) second values, and m and j have a relationship given by 'j/2&#x2212;1&#x2264;m&#x2264;j/2+1'.

Magnetic memory including meomory units and circuits for reading and writing data and memory system

A memory device according to an embodiment includes: a plurality of memory cells including a storage element having a first and second terminals; a reference resistor having a third and fourth terminals; a first current source electrically connected to the first terminal of the storage element in the selected memory cell; a second current source electrically connected to the third terminal; and a determination circuit that determines the greater one among a resistance value of a storage element of selected one and a resistance value of the reference resistor, the resistance value of the reference resistor being smaller than a middle value between a mean value of first resistance values obtained from the storage elements in the high-resistance state and a mean value of second resistance values obtained from the storage elements in the low-resistance state, and greater than the mean value of the second resistance values.

Memory device

A cache memory has cache memory circuitry comprising a nonvolatile memory cell to store at least a portion of a data which is stored or is to be stored in a lower-level memory than the cache memory circuitry, a first redundancy code storage comprising a nonvolatile memory cell capable of storing a redundancy code of the data stored in the cache memory circuitry, and a second redundancy code storage comprising a volatile memory cell capable of storing the redundancy code.

Growing community of inventors

Tokyo, Japan

Kazutaka Ikegami