Memory devices and methods of forming the same are provided. A memory device includes a substrate, a first conductive layer, a phase change layer, a selector layer and a second conductive layer. The first conductive layer is disposed over the substrate. The phase change layer is disposed over the first conductive layer. The selector layer is disposed between the phase change layer and the first conductive layer. The second conductive layer is disposed over the phase change layer. In some embodiments, at least one of the phase change layer and the selector layer has a narrow-middle profile.

The present disclosure, in some embodiments, relates to a method of forming a resistive random access memory (RRAM) device. The method includes forming one or more bottom electrode films over a lower interconnect layer within a lower inter-level dielectric layer. A data storage film having a variable resistance is formed above the one or more bottom electrode films. A lower top electrode film including a metal is over the data storage film, one or more oxygen barrier films are over the lower top electrode film, and an upper top electrode film including a metal nitride is formed over the one or more oxygen barrier films. The one or more oxygen barrier films include one or more of a metal oxide film and a metal oxynitride film. The upper top electrode film is formed to be completely confined over a top surface of the one or more oxygen barrier films.

A single memory cell array is formed to maintain current delivery and mitigate current spike through the deposition of resistive materials in two or more regions of the array, including at least one region of memory cells nearer to contacts on the conductive lines and at least one region of memory cells farther from the contacts, where the contacts connect the conductive lines to the current source. Higher and lower resistive materials are introduced during the formation of the memory cells and the conductive lines based on the boundaries and dimensions of the two or more regions using a photo mask. Multiple memory cell arrays formed to maintain current delivery and mitigate current spike can be arranged into a three-dimensional memory cell array. The regions of memory cells in each memory cell array can vary depending on resistance at the contacts on the conductive lines that provide access to the memory cells, where the resistance can vary from one memory cell array to another.

The present disclosure, in some embodiments, relates to a memory device. The memory device includes a dielectric protection layer having sidewalls defining an opening over a conductive interconnect within an inter-level dielectric (ILD) layer. A bottom electrode structure extends from within the opening to directly over the dielectric protection layer. A variable resistance layer is over the bottom electrode structure and a top electrode is over the variable resistance layer. A top electrode via is disposed on the top electrode and directly over the dielectric protection layer.

Provided are a resistive random access memory and a manufacturing method thereof. The resistive random access memory includes first, second, and third electrodes, a variable resistance layer, a selection layer, and first and second bit lines. The second electrode and the third electrode are on the first electrode. The second and third electrodes are separated from each other and overlapped with the sidewall and the top surface of the first electrode. The variable resistance layer is between the first and second electrodes and between the first and third electrodes. The selection layer is between the variable resistance layer and the first electrode. The first bit line is on the second electrode and electrically connected to the second electrode via a first contact. The second bit line is on the third electrode and electrically connected to the third electrode via a second contact.

Some embodiments relate to a memory device. The memory device includes a first electrode overlying a substrate. A data storage layer overlies the first electrode. A second electrode overlies the data storage layer. A conductive bridge is selectively formable within the data storage layer to couple the first electrode to the second electrode. An active metal layer is disposed between the data storage layer and the second electrode. A buffer layer is disposed between the active metal layer and the second electrode. The buffer layer has a lower reactivity to oxygen than the active metal layer.

Provided is a memristor including an active electrode made of a first conductive material including an active metal; an inert electrode spaced from and facing toward the active electrode and made of a second conductive material having an ionization energy greater than the ionization energy of the first conductive material; and a resistive switching layer including: a porous insulating layer disposed between the active electrode and the inert electrode, wherein the porous insulating layer has through-channel holes defined therein extending from a bottom face to a top face thereof; and conductive filaments respectively formed inside the through-channel holes.

A method of manufacturing a memory device includes sequentially forming and then etching a preliminary selection device layer, a preliminary middle electrode layer, and a preliminary variable resistance layer on a substrate, thereby forming a selection device, a middle electrode, and a variable resistance layer. At least one of a side portion of the selection device or a side portion of the variable resistance layer is removed so that a first width of the middle electrode in a first direction parallel to a top of the substrate is greater than a second width of the variable resistance layer in the first direction or a third width of the selection device in the first direction. A capping layer is formed on at least one of a side wall of the etched side portion of the selection device or a side wall of the etched side portion of the variable resistance layer.

A memory cell including a two-terminal re-writeable non-volatile memory element having at least two layers of conductive metal oxide (CMO), which, in turn, can include a first layer of CMO including mobile oxygen ions, and a second layer of CMO formed in contact with the first layer of CMO to cooperate with the first layer of CMO to form an ion obstruction barrier. The ion obstruction barrier is configured to inhibit transport or diffusion of a subset of mobile ion to enhance, among other things, memory effects and cycling endurance of memory cells. At least one layer of an insulating metal oxide that is an electrolyte to the mobile oxygen ions and configured as a tunnel barrier is formed in contact with the second layer of CMO.

A phase change memory device based on a nano current channel is provided. A nano current channel layer structure is adopted and configured to limit the current channel. As such, when flowing through the layer, the current enters the phase change layer from nano crystal grains with high electrical conductivity, and the current is thereby confined in the nano current channels. By using the nano-scale conductive channels, the contact area between the phase change layer and the electrode layer is significantly decreased, the current density at local contact channel is significantly increased, and heat generation efficiency of the current in the phase change layer is improved. Moreover, an electrically insulating and heat-insulating material with low electrical conductivity and low thermal conductivity prevents heat in the phase change layer from being dissipated to the electrode layer, and Joule heat utilization efficiency of the phase change layer is thereby improved.