Micron Technology Incorporated

Other

Stmicroelectronics S.r.l.

Efrem Bolandrina

Ferdinando Bedeschi

Daniele Vimercati

Andrea Martinelli

Christophe Vincent Antoine Laurent

Graziano Mirichigni

Umberto Di Vincenzo

Riccardo Muzzetto

Stefan Frederik Schippers

Corrado Villa

Gerald J Barkley

Federico Pio

Paolo Fantini

Pierguido Garofalo

Andrea Ghetti

Claudio Nava

Marco Onorato

Claudia Palattella

Sara Fiorina

Methods, systems, and devices for memory array seasoning are described. Some memory cells may have an undesirably high threshold voltage and thus a seasoning operation may be performed on a target memory cell. To season the target memory cell, a bit line and a word line associated with the cell may be activated. Additionally or alternatively, a word line coupled with a second memory cell (e.g., a helper memory cell) that shares the activated bit line may be activated. Accordingly, current flowing across the target memory cell may be increased, which may reduce its threshold voltage.

Memory array seasoning

Methods, systems, and devices for parallel access in a memory array are described. A set of memory cells of a memory device may be associated with an array of conductive structures, where such structures may be coupled using a set of transistors or other switching components that are activated by a first driver. The set of memory cells may be divided into two or more subsets of memory cells, where each subset may be associated with a respective second driver for driving access currents through memory cells of the subset. Two or more of such second drivers may operate concurrently, which may support distributing current or distributing associated circuit structures across a different footprint of the memory device than other different implementations with a single such second driver.

Parallel access in a memory array

Methods, systems, and devices for shared decoder architecture for three-dimensional memory arrays are described. A memory device may include pillars coupled to an access line using two transistors positioned between the pillar and the access line. The gates of the two transistors may be coupled with respective gate lines coupled with circuitry configured to bias the gate line as part of an access operation for a memory cell coupled with the pillar. In some cases, the circuitry may be positioned between tiles of the memory device, at an end of one or more tiles of the memory device, between word line combs of a tile of the memory device, or a combination thereof.

Shared decoder architecture for three-dimensional memory arrays

Methods, systems, and devices for a single plate configuration and memory array operation are described. A non-volatile memory array may utilize a single plate to cover a subset of the array. One or more memory cells of the subset may be selected by operating the plate and an access line of an unselected memory cell at a fixed voltage. A second voltage may be applied to an access line of the selected cell, and subsequently reduced to perform an access operation. Removing the applied voltage may allow for the memory cell to undergo a recovery period prior to a subsequent access operation.

Single plate configuration and memory array operation

Methods, systems, and devices for techniques for indicating row activation are described. A memory device may receive an indication associated with an activation command, which may enable the memory device to begin some aspects of an activation operation before receiving the associated activation command. The indication may include a location of a next row to access as part of the activation command. The indication may be included in a previous activation command or in a precharge command. The memory device may begin activation operations for the next row before the precharge operation of the current row is complete. The memory device may receive the activation command for the next row after receiving the indication, and may complete the activation operations upon receiving the activation command.

Techniques for indicating row activation

Systems, methods, and apparatus related to memory devices. In one approach, a vertical three-dimensional cross-point memory device uses digit line decoders that include, on the digit line side of memory cells, a current limiter and sensing circuit configured to control program current in either of positive or negative program polarities, as selected by a controller. Two current limiters are each used on the digit line side of each memory cell. A negative polarity current limiter is used for pull-up, and a positive polarity current limiter is used for pull-down. A negative polarity sensing circuit is used between the respective digit line decoder and a positive supply voltage. A positive polarity sensing circuit is used between the respective digit line decoder and a negative supply voltage. The current limiter and sensing circuit pair of the same polarity is coupled to each digit line decoder based on the selected program polarity.

Program current controller and sense circuit for cross-point memory devices

The present disclosure provides a memory device and accessing/de-selecting methods thereof. The memory device comprises a memory layer including a vertical three-dimensional (3D) memory array of memory cells formed therein, wherein a memory cell is accessed through a word line and a digit line orthogonal to each other, and the digit line is in a form of conductive pillar extending vertically; a pillar selection layer formed under the memory layer and having thin film transistors (TFTs) formed therein for accessing memory cells; and a peripheral circuit layer formed under the pillar selection layer and having a sense amplifier and a decoding circuitry for word lines and bit lines, wherein a TFT is configured for each pillar.

Vertical 3D memory device and accessing method

Techniques are described for maintaining a stable voltage difference in a memory device, for example, during a critical operation (e.g., a sense operation). The voltage difference to be maintained may be a read voltage across a memory cell or a difference associated with a reference voltage, among other examples. A component (e.g., a local capacitor) may be coupled, before the operation, with a node biased to a first voltage (e.g., a global reference voltage) to sample a voltage difference between the first voltage and a second voltage while the circuitry is relatively quiet (e.g., not noisy). The component may be decoupled from the node before the operation such that a node of the component (e.g., a capacitor) may be allowed to float during the operation. The voltage difference across the component may remain stable during variations in the second voltage and may provide a stable voltage difference during the operation.

Reference voltage management

Techniques herein may allow a row of a subarray in a bank of a memory device to be activated before a precharge operation has been completed for a previously opened row of memory cells in the same bank. Each subarray within the bank may be associated with a respective local latching circuit, which may be used to maintain phases at the subarray independent of subsequent commands to the same bank. For example, the latching circuit may internalize timing signals triggered by a precharge command for a first row such that if an activation command is received for a different subarray in the same bank at a time before the precharge operation of the first row is complete, the precharge operation may continue until the first row is closed, as the timing signals triggered by the precharge command may be maintained locally at the subarray using the latching circuit.

Parallel access for memory subarrays

A memory device with single transistor drivers and methods to operate the memory device are described. In some embodiments, the memory device may comprise memory cells at cross points of access lines of a memory array, a first even single transistor driver configured to drive a first even access line to a discharging voltage during an IDLE phase, to drive the first even access line to a floating voltage during an ACTIVE phase, and to drive the first even access line to a read/program voltage during a PULSE phase, and a first odd single transistor driver configured to drive a first odd access line, the first odd access line physically adjacent to the first even access line, to the discharging voltage during the IDLE phase, to drive the first odd access line to the floating voltage during the ACTIVE phase, and to drive the first odd access line to a shielding voltage during the PULSE phase.

Memory device with single transistor drivers and methods to operate the memory device

Methods, systems, and devices for sensing techniques for a memory cell are described to enable a latch to sense a logic state of a memory cell. A transistor coupled with a memory cell may boost a first voltage associated with the memory cell to a second voltage via one or more parasitic capacitances of the transistor. The second voltage may be developed on a first node of a sense component, and the second voltage may be shifted to a third voltage at a first node of the sense component by applying a voltage to a shift node coupled with a capacitor of the sense component. Similar boosting and shifting operations may be performed to develop a reference voltage on a second node of the sense component. The sense component may sense the state of the memory cell by comparing with the reference voltage.

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Fiorano al Serio, Italy

Efrem Bolandrina