The present disclosure provides a 2-dimensional (2D) non-volatile switch (2DNS), with a vertical metal-insulator-metal (MIM) structure that includes a semiconducting monolayer crystalline non-metallic atomic sheet sandwiched between a top metal electrode and a bottom metal electrode. The 2DNS is able to perform stable non-volatile resistance switching, including both unipolar and bipolar switching, with a high ON/OFF ratio, low ON resistance, and low operating voltage. The monolayer atomic sheet may include hexagonal boron nitride (h-BN) or a transition metal dichalcogenide (TMD), such as MoS.sub.2, MoSe.sub.2, WS.sub.2, or WSe.sub.2. The present disclosure also provides methods for synthesizing a semiconducting monolayer crystalline non-metallic atomic sheet on a target substrate. The monolayer atomic sheet may include h-BN or a TMD, such as MoS.sub.2, MoSe.sub.2, WS.sub.2, or WSe.sub.2.

A switching element includes a lower barrier electrode disposed on a substrate, a switching pattern disposed on the lower barrier electrode, and an upper barrier electrode disposed on the switching pattern. The switching pattern includes a first switching pattern, and a second switching pattern disposed on the first switching pattern and having a density different from a density of the first switching pattern.

A memory device and method of forming the same are provided. The memory device includes a first memory cell disposed over a substrate. The first memory cell includes a transistor and a data storage structure coupled to the transistor. The transistor includes a gate pillar structure, a channel layer laterally wrapping around the gate pillar structure, a source electrode surrounding the channel layer, and a drain electrode surrounding the channel layer. The drain electrode is separated from the source electrode a dielectric layer therebetween. The data storage structure includes a data storage layer surrounding the channel layer and sandwiched between a first electrode and a second electrode. The drain electrode of the transistor and the first electrode of the data storage structure share a common conductive layer.

A variable resistance memory device includes first conductive lines, second conductive lines arranged on the first conductive lines, first cell structures at intersections between the first conductive lines and the second conductive lines, each first cell structure including a switching pattern and a variable resistance pattern, first buried structures filling first trenches between the first conductive lines, and second buried structures filling second trenches between the first cell structures. Each first buried structure includes a first liner pattern covering sidewalls of a corresponding first trench, a first filling pattern being disposed on the first liner pattern and in the corresponding first trench, and a first capping pattern sealing the corresponding first trench. The second buried structures extend in the plurality of second trenches and are connected with first capping patterns of the first buried structures.

A memory device includes first conductive lines extending in a first direction, second conductive lines extending in a second direction, and a plurality of memory cells each arranged between the first and second conductive lines and each including a variable resistance memory layer and a switch material pattern. The switch material pattern includes an element injection area arranged in an outer area of the switch material pattern, and an internal area covered by the element injection area. The internal area contains a first content of at least one element from arsenic (As), sulfur (S), selenium (Se), and tellurium (Te), the element injection area contains a second content of the at least one element from As, S, Se, and Te, and the second content has a profile in which a content of the at least one element decreases away from the at least one surface of the switch material pattern.

A method of switching between first and second states of a van der Waals heterostructure, vdWH, memory device, a vdWH memory device, and a method of fabricating a vdWH memory device. The vdWH memory device comprises a first two-dimensional, 2D, material; and a second 2D material, wherein, in a first storage state of the memory device, an interface between the first and second 2D material comprises interfacial states; and wherein, in a second storage state of the memory device, interfacial states are modulated compared to the first memory state.

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.

A method of forming a memory device that includes depositing a first dielectric material within a trench of composed of a second dielectric material; positioning a nanotube within the trench using chemical recognition to the first dielectric material; depositing a dielectric for cation transportation within the trench on the nanotube; and forming a second electrode on the dielectric for cation transportation, wherein the second electrode is composed of a metal.

A memory includes: a first electrode comprising a top boundary and a sidewall; a resistive material layer, disposed above the first electrode, that comprises at least a first portion and a second portion coupled to a first end of the first portion, wherein the resistive material layer presents a variable resistance value; and a second electrode disposed above the resistive material layer.

A memory structure can include a memory cell and a first barrier layer having a maximum hydrogen diffusion coefficient of 1×10.sup.−17 cm.sup.2/s, said first barrier layer adjacent to the memory cell to minimize contaminant movement to or from the memory cell.