A memory cell is manufactured by: (a) forming a stack comprising a first layer made of a phase change material and a second layer made of a conductive material; (b) forming a mask on the stack covering only the memory cell location; and (c) etching portions of the stack not covered by the first mask. The formation of the mask covering only the memory cell location comprises defining a first mask extending in a row direction for each row of memory cell locations and then patterning the first mask in a column direction for each column of memory cell locations.

A three-dimensional memory device includes: a plurality of word line groups including a plurality of word lines; a plurality of bit line groups extending in a vertical direction and including a plurality of bit lines spaced apart from the plurality of word lines; a plurality of memory cells arranged between the plurality of word lines and the plurality of bit lines and including a switching component and a variable resistance memory component; a plurality of global bit line groups connected to the plurality of bit line groups, wherein each of the plurality of global bit line groups includes a plurality of global bit lines electrically connected to a plurality of bit lines included in one bit line group, respectively; and a pad structure including a plurality of connection units and a plurality of pad layers, wherein the plurality of connection units are connected to the plurality of word line groups.

Methods, systems, and devices for techniques for memory cells with sidewall and bulk regions in vertical structures are described. A memory cell may include a first electrode, a second electrode, and a self-selecting storage element between the first electrode and the second electrode. The bulk region may extend between the first electrode and the sidewall region. The bulk region may include a chalcogenide material having a first composition, and the sidewall region may include the chalcogenide material having a second composition that is different than the first composition. Also, the sidewall region may separate the bulk region from the second electrode.

Methods, systems, and devices for techniques for memory cells with sidewall and bulk regions in planar structures are described. A memory cell may include a first electrode, a second electrode, and a self-selecting storage element between the first electrode and the second electrode. A conductive path between the first electrode and the second electrode may extend in a direction away from a plane defined by a substrate. The self-selecting storage element may include a bulk region and a sidewall region. The bulk region may include a chalcogenide material having a first composition, and the sidewall region may include the chalcogenide material having a second composition that is different than the first composition. The bulk region and sidewall region may extend between the first electrode and the second electrode and in the direction away from the plane defined by the substrate.

Methods, systems, and devices for a memory device with laterally formed memory cells are described. A material stack that includes a conductive layer between multiple dielectric layers may be formed, where the conductive layer and dielectric layers may form a channel in a sidewall of the material stack. The channel may be filled with one or more materials, where a first side of an outermost material of the one or more materials may be exposed. An opening may be formed in the material stack that exposes a second side of at least one material of the one or more materials. The opening may be used to replace a portion of the at least one material with a chalcogenide material where the electrode materials may be formed before replacing the portion of the at least one material with the chalcogenide material.

Methods, systems, and devices for techniques that support sidewall structures for memory cells in vertical structures are described. A memory cell may include a first electrode, a second electrode, and a self-selecting storage element between the first electrode and the second electrode. The self-selecting storage element may extend between the first electrode and the second electrode in a direction that is parallel with a plane defined by the substrate. The self-selecting storage element may also include a bulk region and a sidewall region. The bulk region may include a chalcogenide material having a first composition, and the sidewall region may include the chalcogenide material having a second composition that is different than the first composition. Also, the sidewall region may extend between the first electrode and the second electrode.

A semiconductor device includes first conductive lines extending in a first direction, second conductive lines extending in a second direction, memory cells disposed between the first conductive lines and the second conductive lines, each memory cell disposed at an intersection of a first conductive line and a second conductive line, and a passive material between the memory cells and at least one of the first conductive lines and the second conductive lines. Related semiconductor devices and electronic devices are disclosed.

An example apparatus can include a memory array and a memory controller. The memory array can include a first portion including a first plurality of memory cells. The memory array can further include a second portion including a second plurality of memory cells. The memory controller can be coupled to the first portion and the second portion. The memory controller can be configured to operate the first plurality of memory cells for short-term memory operations. The memory controller can be further configured to operate the second plurality of memory cells for long-term memory operations.

A selective non-volatile memory device includes a first electrode, a second electrode and at least one layer made of an active material. The device has at least two programmable memory states associated with two voltage thresholds and also provides a selective role when it is in a highly resistive state.

A memory cell includes a bottom electrode, a first dielectric layer, a variable resistance layer, and a top electrode. The first dielectric layer laterally surrounds the bottom electrode. A top surface of the bottom electrode is located at a level height lower than that of a top surface of the first dielectric layer. The variable resistance layer is disposed on the bottom electrode and the first dielectric layer. The variable resistance layer contacts the top surface of the bottom electrode and the top surface of the first dielectric layer. The top electrode is disposed on the variable resistance layer.