Abstract: Methods, systems, and devices for a capacitive pillar architecture for a memory array are described. An access line within a memory array may be, include, or be coupled with a pillar. The pillar may include an exterior electrode, such as a hollow exterior electrode, surrounding an inner dielectric material that may further surround an interior, core electrode. The interior electrode may be maintained at a voltage level during at least a portion of an access operation for a memory cell coupled with the pillar. Such a pillar structure may increase a capacitance of the pillar, for example, based on a capacitive coupling between the interior and exterior electrodes. The increased capacitance may provide benefits associated with operating the memory array, such as increased memory cell programming speed, programming reliability, and read disturb immunity.

Abstract: Methods, systems, and devices for techniques for forming self-aligned memory structures are described. Aspects include etching a layered assembly of materials including a first conductive material and a first sacrificial material to form a first set of channels along a first direction that creates a first set of sections. An insulative material may be deposited within each of the first set of channels and a second sacrificial material may be deposited onto the first set of sections and the insulating material. A second set of channels may be etched into the layered assembly of materials along a second direction that creates a second set of sections, where the second set of channels extend through the first and second sacrificial materials. Insulating material may be deposited in the second set of channels and the sacrificial materials removed leaving a cavity. A memory material may be deposited in the cavity.

Abstract: Methods, systems, and devices for decoding for a memory device are described. A decoder of a memory device may include transistors in a first layer between a memory array and a second layer that includes one or more components associated with the memory array. The second layer may include CMOS pre-decoding circuitry, among other components. The decoder may include CMOS transistors in the first layer. The CMOS transistors may control which voltage source is coupled with an access line based on a gate voltage applied to a p-type transistor and a n-type transistor. For example, a first gate voltage applied to a p-type transistor may couple a source node with the access line and bias the access line to a source voltage. A second gate voltage applied to the n-type transistor may couple a ground node with the access line and bias the access line to a ground voltage.

Abstract: A memory cell design is disclosed. The design is particularly well-suited for three-dimensional cross-point (3D X-point) memory configurations. Various embodiments of the memory cell design include one or more electrodes having an increased resistance compared to existing memory cell designs or compared to other electrodes within a same memory cell. A memory device includes an array of memory cells with each memory cell arranged between a word line and a bit line of the memory device. Some embodiments include additional material layers to increase memory cell resistance. Some embodiments include electrodes having an increased thickness to increase the resistance. Some embodiments include electrodes having a composition with a higher resistivity. Some embodiments include electrodes with increased interface resistance. Some embodiments include a combination of such features.

Abstract: Methods, systems, and devices for self-selecting memory with horizontal access lines are described. A memory array may include first and second access lines extending in different directions. For example, a first access line may extend in a first direction, and a second access line may extend in a second direction. At each intersection, a plurality of memory cells may exist, and each plurality of memory cells may be in contact with a self-selecting material. Further, a dielectric material may be positioned between a first plurality of memory cells and a second plurality of memory cells in at least one direction. each cell group (e.g., a first and second plurality of memory cells) may be in contact with one of the first access lines and second access lines, respectively.

Abstract: The present disclosure includes memory cells having resistors, and methods of forming the same. An example method includes forming a first conductive line, forming a second conductive line, and forming a memory element between the first conductive line and the second conductive line. Forming the memory element can include forming one or more memory materials, and forming a resistor in series with the one or more memory materials. The resistor can be configured to reduce a capacitive discharge through the memory element during a state transition of the memory element.

Abstract: Methods, systems, and devices for decoding for a memory device are described. A decoder may include a first vertical n-type transistor and a second vertical n-type transistor that extends in a third direction relative to a die of a memory array. The first vertical n-type transistor may be configured to selectively couple an access line with a source node and the second n-type transistor may be configured to selectively couple the access line with a ground node. To activate the access line coupled with the first and second vertical n-type transistors, the first vertical n-type transistor may be activated, the second vertical n-type transistor may be deactivated, and the source node coupled with the first vertical n-type transistor may have a voltage applied that differs from a ground voltage.

Abstract: Methods, systems, and devices for a capacitive pillar architecture for a memory array are described. An access line within a memory array may be, include, or be coupled with a pillar. The pillar may include an exterior electrode, such as a hollow exterior electrode, surrounding an inner dielectric material that may further surround an interior, core electrode. The interior electrode may be maintained at a voltage level during at least a portion of an access operation for a memory cell coupled with the pillar. Such a pillar structure may increase a capacitance of the pillar, for example, based on a capacitive coupling between the interior and exterior electrodes. The increased capacitance may provide benefits associated with operating the memory array, such as increased memory cell programming speed, programming reliability, and read disturb immunity.

Abstract: Methods, systems, and devices for decoding for a memory device are described. A decoder of a memory device may include transistors in a first layer between a memory array and a second layer that includes one or more components associated with the memory array. The second layer may include CMOS pre-decoding circuitry, among other components. The decoder may include CMOS transistors in the first layer. The CMOS transistors may control which voltage source is coupled with an access line based on a gate voltage applied to a p-type transistor and a n-type transistor. For example, a first gate voltage applied to a p-type transistor may couple a source node with the access line and bias the access line to a source voltage. A second gate voltage applied to the n-type transistor may couple a ground node with the access line and bias the access line to a ground voltage.

Abstract: Techniques are provided for programming a self-selecting memory cell that stores a first logic state. To program the memory cell, a pulse having a first polarity may be applied to the cell, which may result in the memory cell having a reduced threshold voltage. During a duration in which the threshold voltage of the memory cell may be reduced (e.g., during a selection time), a second pulse having a second polarity (e.g., a different polarity) may be applied to the memory cell. Applying the second pulse to the memory cell may result in the memory cell storing a second logic state different than the first logic state.

Abstract: Methods, systems, and devices for a resistive interface material are described. A memory device may be fabricated using a sequence of steps that include forming a stack of materials by depositing a first metal layer, depositing a first electrode layer on the metal layer, depositing a memory material on the first electrode layer to form one or more memory cells, depositing a second electrode layer on the memory material, and depositing a second metal layer on the second electrode layer. A lamina (or multiple) having a relatively high resistivity may be included in the stack of materials to reduce or eliminate a current spike that may otherwise occur across the memory cells during an access operation.

Abstract: An example apparatus includes a three-dimensional (3D) memory array including a sense line and a plurality of vertical stacks. Each respective on of the vertical stacks includes a different respective portion of the sense line, a first memory cell coupled to that portion of the sense line, a second memory cell coupled to that portion of the sense line, a first access line coupled to the first memory cell and a second access line coupled to the second memory cell. The first and second access lines are perpendicular to the sense line.

Abstract: Methods, systems, and devices for split pillar architectures for memory devices are described. A memory device may include a substrate arranged with conductive contacts in a pattern and openings through alternative layers of conductive and insulative material that may decrease the spacing between the openings while maintaining a dielectric thickness to sustain the voltage to be applied to the array. After etching material, an insulative material may be deposited in a trench. Portions of the insulative material may be removed to form openings, into which cell material is deposited. Conductive pillars may extend perpendicular to the planes of the conductive material and the substrate, and couple to conductive contacts. The conductive pillars may be divided to form first and second pillars.

Abstract: Methods, systems, and devices for programming enhancement in memory cells are described. An asymmetrically shaped memory cell may enhance ion crowding at or near a particular electrode, which may be leveraged for accurately reading a stored value of the memory cell. Programming the memory cell may cause elements within the cell to separate, resulting in ion migration towards a particular electrode. The migration may depend on the polarity of the cell and may create a high resistivity region and low resistivity region within the cell. The memory cell may be sensed by applying a voltage across the cell. The resulting current may then encounter the high resistivity region and low resistivity region, and the orientation of the regions may be representative of a first or a second logic state of the cell.

Abstract: Methods, systems, and devices for a capacitive pillar architecture for a memory array are described. An access line within a memory array may be, include, or be coupled with a pillar. The pillar may include an exterior electrode, such as a hollow exterior electrode, surrounding an inner dielectric material that may further surround an interior, core electrode. The interior electrode may be maintained at a voltage level during at least a portion of an access operation for a memory cell coupled with the pillar. Such a pillar structure may increase a capacitance of the pillar, for example, based on a capacitive coupling between the interior and exterior electrodes. The increased capacitance may provide benefits associated with operating the memory array, such as increased memory cell programming speed, programming reliability, and read disturb immunity.

Abstract: Methods, systems, and devices for polarity-written cell architectures for a memory device are described. In an example, the described architectures may include memory cells that each include or are otherwise associated with a material configured to store one of a set of logic states based at least in part on a polarity of a write voltage applied to the material. Each of the memory cells may also include a cell selection component configured to selectively couple the material with an access line. In some examples, the material may include a chalcogenide, and the material may be configured to store each of the set of logic states in an amorphous state of the chalcogenide. In various examples, different logic states may be associated with different compositional distributions of the material of a respective memory cell, different threshold characteristics of the material of a respective memory cell, or other characteristics.

Abstract: Methods, systems, and devices related to techniques to access a self-selecting memory device are described. A self-selecting memory cell may store one or more bits of data represented by different threshold voltages of the self-selecting memory cell. A programming pulse may be varied to establish the different threshold voltages by modifying one or more time durations during which a fixed level of voltage or current is maintained across the self-selecting memory cell. The self-selecting memory cell may include a chalcogenide alloy. A non-uniform distribution of an element in the chalcogenide alloy may determine a particular threshold voltage of the self-selecting memory cell. The shape of the programming pulse may be configured to modify a distribution of the element in the chalcogenide alloy based on a desired logic state of the self-selecting memory cell.

Abstract: Methods, systems, and devices for reading a multi-level memory cell are described. The memory cell may be configured to store three or more logic states. The memory device may apply a first read voltage to a memory cell to determine a logic state stored by the memory cell. The memory device may determine whether a first snapback event occurred and apply a second read voltage based on determining that the first snapback event failed to occur based on applying the first read voltage. The memory device may determine whether a second snapback event occurred and determine the logic state based on whether the first snapback event or the second snapback event occurred.

Abstract: Techniques are provided for programming a self-selecting memory cell that stores a first logic state. To program the memory cell, a pulse having a first polarity may be applied to the cell, which may result in the memory cell having a reduced threshold voltage. During a duration in which the threshold voltage of the memory cell may be reduced (e.g., during a selection time), a second pulse having a second polarity (e.g., a different polarity) may be applied to the memory cell. Applying the second pulse to the memory cell may result in the memory cell storing a second logic state different than the first logic state.

Abstract: Methods, systems, and devices for read refresh operations are described. A memory device may include a plurality of sub-blocks of memory cells. Each sub-block may undergo a quantity of access operations (e.g., read operations, write operations). Based on the quantity of access operations performed on any one sub-block over a period of time, a read refresh operation may be performed on the memory cells of the sub-block. A read refresh operation may refresh and/or restore the data stored to the memory cells of the sub-block, and be initiated based on the memory device receiving an operation code (e.g., from a host device).