A selector according to an embodiment of the present disclosure includes a first electrode; a second electrode disposed opposite to the first electrode; an ion supply layer disposed between the first electrode and the second electrode to be on the side of the first electrode and doped with a metal, wherein the doped metal diffuses toward the second electrode; a switching layer disposed between the first electrode and the second electrode to be on the side of the second electrode, wherein the doped metal diffuses from the ion supply layer into the switching layer so that metal concentration distribution inside the switching layer is changed to generate metal filaments; and a diffusion control layer inserted between the ion supply layer and the switching layer, wherein the diffusion control layer serves to adjust electrical characteristics related to the generated metal filaments as the amount of the diffusing metal is adjusted in proportion to a thickness of the diffusion control layer.

A semiconductor device includes a substrate, a plurality of word line structures disposed over the substrate to be spaced apart from each other in a first direction perpendicular to a surface of the substrate. Each of the plurality of word line structures extends in a second direction parallel to the surface of the substrate. In addition, the semiconductor device includes a switching layer disposed over the substrate to contact side surfaces of the plurality of word line structures, and bit line structures disposed over the substrate to extend in the first direction and to contact a surface of the switching layer. The switching layer is configured to perform a threshold switching operation, and has a variable programmable threshold voltage.

A non-volatile memory structure, and methods of manufacture, which may include a first memory element and a second memory element between a first terminal and a second terminal. The first memory element and the second memory element may be in parallel with each other between the first and second terminal. This may enable the hybrid non-volatile memory structure to store values as a combination of the conductance for each memory element, thereby enabling better tuning of set and reset conductance parameters.

Methods, systems, and devices for tapered memory cell profiles are described. A tapered profile memory cell may mitigate shorts in adjacent word lines, which may be leveraged for accurately reading a stored value of the memory cell. The memory device may include a self-selecting memory component with a bottom surface and a top surface opposite the bottom surface. In some cases, the self-selecting memory component may taper from the bottom surface to the top surface. In other examples, the self-selecting memory component may taper from the top surface to the bottom surface. The top surface of the self-selecting memory component may be coupled to a top electrode, and the bottom surface of the self-selecting memory component may be coupled to a bottom electrode.

Methods, systems, and devices for fabrication of memory cells are described. An electrode layer may have an initial thickness variation after being formed. The electrode layer may be smoothened prior to forming additional layers of a memory cell, thus decreasing the thickness variation. The subsequent layer fabricated may have a thickness variation that may be dependent on the thickness variation of the electrode layer. By decreasing the thickness variation of the electrode layer prior to forming the subsequent layer, the subsequent layer may also have a decreased thickness variation. The decreased thickness variation of the subsequent layer may impact the electrical behavior of memory cells formed from the subsequent layer. In some cases, the decreased thickness variation of the subsequent layer may allow for more predictable voltage thresholds for such memory cells, thus increasing the read windows for the memory cells.

A method of forming a metal chalcogenide material. The method comprises introducing a metal precursor and a chalcogenide precursor into a chamber, and reacting the metal precursor and the chalcogenide precursor to form a metal chalcogenide material on a substrate. The metal precursor is a carboxylate of an alkali metal, an alkaline earth metal, a transition metal, a post-transition metal, or a metalloid. The chalcogenide precursor is a hydride, alkyl, or aryl precursor of sulfur, selenium, or tellurium or a silylhydride, silylalkyl, or silylaryl precursor of sulfur, selenium, or tellurium. Methods of forming a memory cell including the metal chalcogenide material are also disclosed, as are memory cells including the metal chalcogenide material.

A memory cell design is disclosed. The memory cell structure includes phase change and selector layers stacked between top and bottom electrodes. An ohmic contact may be included between the phase change and selector layers. A multi-layer liner structure is provided on sidewalls of the phase change layer. In some such cases, the liner structure is above and not on sidewalls of the selector layer. The liner structure includes a first dielectric layer, and a second dielectric layer on the first dielectric layer. The liner structure includes a third dielectric layer on the second dielectric layer and that is sacrificial in nature, and may not be present in the final structure. The second dielectric layer comprises a high-k dielectric material or a metal silicate material. The second dielectric layer protects the phase change layer from lateral erosion and physical vertical etch and provides etch selectivity during the fabrication process.

Methods, systems, and devices for memory arrays having graded memory stack resistances are described. An apparatus may include a first subset of memory stacks having a first resistance based on a physical and/or electrical distance of the first subset of memory stacks from at least one of a first driver component or a second driver component. The apparatus may include a second subset of memory stacks having a second resistance that is less than the first resistance based on a physical and/or electrical distance of the second subset of memory from at least one of the first driver component or the second driver component.

A new liner structure for improving memory cell design is disclosed that incorporates a boron nitride dielectric layer. An example memory device includes an array of memory cells with each of at least some of the memory cells having a stack of layers, the stack comprising at least one phase change layer. A dielectric layer is provisioned over one or more sidewalls of at least the phase change layer. The dielectric layer comprises both nitrogen and boron. The dielectric layer may be part of a liner structure that includes multiple layers, such as an alternating layer stack of boron nitride and silicon nitride. The dielectric layer can be deposited at low temperature (e.g., less than about 300° C.) while maintaining a low hydrogen content and a relatively high thermal conductivity.

A metasurface unit cell for use in constructing a metasurface array is provided. The unit cell may include a ground plane layer comprising a first conductive material, and a phase change material layer operably coupled to the ground plane layer. The phase change material layer may include a phase change material configured to transition between an amorphous phase and a crystalline phase in response to a stimulus. The unit cell may further include a patterned element disposed adjacent to the phase change material layer and includes a second conductive material. In response to the phase change material transitioning from a first phase to a second phase, the metasurface unit cell may resonate to generate an electromagnetic signal having a defined wavelength. The first phase may be the amorphous phase or the crystalline phase and the second phase may be the other of the amorphous phase or the crystalline phase.