A method includes providing a substrate having a conductive column, a dielectric layer over the conductive column, and a plurality of sacrificial blocks over the dielectric layer, the plurality of sacrificial blocks surrounding the conductive column from a top view; depositing a sacrificial layer covering the plurality of sacrificial blocks, the sacrificial layer having a dip directly above the conductive column; depositing a hard mask layer over the sacrificial layer; removing a portion of the hard mask layer from a bottom of the dip; etching the bottom of the dip using the hard mask layer as an etching mask, thereby exposing a top surface of the conductive column; and forming a conductive material inside the dip, the conductive material being in physical contact with the top surface of the conductive column.

A method includes providing a substrate having a conductive column, a dielectric layer over the conductive column, and a plurality of sacrificial blocks over the dielectric layer, the plurality of sacrificial blocks surrounding the conductive column from a top view; depositing a sacrificial layer covering the plurality of sacrificial blocks, the sacrificial layer having a dip directly above the conductive column; depositing a hard mask layer over the sacrificial layer; removing a portion of the hard mask layer from a bottom of the dip; etching the bottom of the dip using the hard mask layer as an etching mask, thereby exposing a top surface of the conductive column; and forming a conductive material inside the dip, the conductive material being in physical contact with the top surface of the conductive column.

The present disclosure provides an apparatus, including: a substrate; a bottom electrode formed on the substrate; a first base oxide layer formed on the bottom electrode; a first geometric confining layer formed on the first base oxide layer, wherein the first geometric confining layer comprises a first plurality of pin-holes; a second base oxide layer formed on the first geometric confining layer and connected to a first top surface of the first base oxide layer via the first plurality of pin-holes; and a top electrode formed on the second base oxide layer. The first base oxide layer includes TaOx, HfOx, TiOx, ZrOx, or a combination thereof. The first geometric confining layer comprises Al.sub.2O.sub.3, SiO.sub.2, Si.sub.3N.sub.4, Y.sub.2O.sub.3, Gd.sub.2O.sub.3, Sm.sub.2O.sub.3, CeO.sub.2, Er.sub.2O.sub.3, or a combination thereof.

Embodiments disclosed herein include an RRAM cell. The RRAM cell may include a first nanowire electrically connected to a first wordline electrode. The nanowire may include a first sharpened point distal from the first wordline electrode. The RRAM cell may also include a metal contact electrically connected to a bitline electrode and a high-κ dielectric layer directly between the nanowire and the metal contact.

A semiconductor memory device has a first wiring extending in a first direction and a second wiring extending in a second direction. The first and second wirings are spaced from each other in a third direction. The second wiring has a first recess facing the first wiring. A resistance change memory element is connected between the first and second wirings. A conductive layer is between the resistance change memory element and the second wiring and includes a first protrusion facing the second wiring. A switching portion is between the conductive layer and the second wiring and includes a second recess facing the conductive layer and a second protrusion facing the second wiring. The first protrusion is in the second recess. The second protrusion is in the first recess. The switching portion is configured to switch conductivity state according to voltage between the first wiring and the second wiring.

Structures for a resistive memory element and methods of forming a structure for a resistive memory element. A resistive memory element has a first electrode, a second electrode partially embedded in the first electrode, a third electrode, and a switching layer positioned between the first electrode and the third electrode. The second electrode includes a tip positioned in the first electrode adjacent to the switching layer and a sidewall that tapers to the tip.

A memory device may be provided, including a substrate; one or more bottom electrodes arranged over the substrate; one or more switching layers arranged over the one or more bottom electrodes; and a plurality of top electrodes arranged over the one or more switching layers. Each of the one or more bottom electrodes may include at least one corner tip facing the switching layer, and an angle of each of the at least one corner tip may be less than ninety degrees.

A memory cell includes a bottom electrode, a memory element, a selector, a top electrode and a connecting structure. The memory element is disposed on the bottom electrode. The selector is disposed on the memory element. The top electrode is disposed on the selector. The connecting structure is electrically connecting the memory element to the selector, wherein the connecting structure includes a base portion and a pillar portion. The base portion disposed on the memory element. The pillar portion is disposed on the base portion, wherein the pillar portion is physically connected to the selector, and includes a tapered pillar foot.

The disclosed subject matter relates generally to structures, memory devices and a method of forming the same. More particularly, the present disclosure relates to resistive random-access (ReRAM) memory devices having a spacer element on a side of the electrode. The present disclosure provides a memory device including a first electrode having a side, the side has upper and lower portions, a spacer element on the lower portion of the side of the first electrode, a resistive layer on the upper portion of the side of the first electrode, and a second electrode laterally adjacent to the side of the first electrode. The second electrode has a top surface, in which the top surface has a concave profile.

A memory device includes a bottom electrode, an insulating layer, and a top electrode. The bottom electrode includes a plurality of carbon nanotubes. The insulating layer is disposed over the plurality of carbon nanotubes. The top electrode includes a graphene layer separated from the plurality of carbon nanotubes by the insulating layer.