A fabricating method of a resistive random access memory (RRAM) structure is disclosed. The method includes sequentially forming a bottom electrode, a resistive switching layer, and a top electrode. Specifically, the bottom electrode is a first cylinder, the resistive switching layer includes a second cylinder and a three-dimensional disk, and the top electrode is a third cylinder having a top base, a second bottom base, and a sidewall. Next, a spacer that surrounds the resistive switching layer is formed, and a conductive line that encapsulates and directly contacts the top base and sidewall of the third cylinder is subsequently formed. The RRAM structure features the first cylinder embedded within the second cylinder and the three-dimensional disk, and the second cylinder embedded within the third cylinder, enabling increased contact area and resistance difference

Neural network systems and methods are provided. In one embodiment, a method of making a neural network device includes: forming a mesh layer on a substrate, the mesh layer including a matrix of randomly dispersed conductive nano-strands insulated from one another; forming an isolation trench extending into the mesh layer; forming a memristor device extending into the mesh layer, the memristor device including: an electrical conductor, and a layer of memristive material in electrical contact with individual nano-strands of a first set of conductive nano-strands in the mesh layer; forming an electrode extending into the mesh layer and spaced from the memristor device by the isolation trench, wherein the electrode is in electrical contact with individual conductive nano-strands of a second set of conductive nano-strands in the mesh layer; and forming a modulating device bridging the memristor device and the electrode.

Neural network systems and methods are provided. In one embodiment, a method of making a neural network device includes: forming a mesh layer on a substrate, the mesh layer including a matrix of randomly dispersed conductive nano-strands insulated from one another; forming an isolation trench extending into the mesh layer; forming a memristor device extending into the mesh layer, the memristor device including: an electrical conductor, and a layer of memristive material in electrical contact with individual nano-strands of a first set of conductive nano-strands in the mesh layer; forming an electrode extending into the mesh layer and spaced from the memristor device by the isolation trench, wherein the electrode is in electrical contact with individual conductive nano-strands of a second set of conductive nano-strands in the mesh layer; and forming a modulating device bridging the memristor device and the electrode.

A phase change material switching circuit may be provided by forming a semiconductor circuit including a power amplifier and a low noise amplifier on a substrate; forming metal interconnect structures embedded in first dielectric material layers over the power amplifier and the low noise amplifier; forming a first phase change material (PCM) switch and a second PCM switch over the first dielectric material layers, wherein the first PCM switch includes a first electrode and a second electrode, and the second PCM switch includes a third electrode and a fourth electrode, wherein the second electrode is electrically connected to the third electrode to form a common electrical node; and electrically connecting a radio-frequency (RF) antenna to the common electrical node.

A phase change material switching circuit may be provided by forming a semiconductor circuit including a power amplifier and a low noise amplifier on a substrate; forming metal interconnect structures embedded in first dielectric material layers over the power amplifier and the low noise amplifier; forming a first phase change material (PCM) switch and a second PCM switch over the first dielectric material layers, wherein the first PCM switch includes a first electrode and a second electrode, and the second PCM switch includes a third electrode and a fourth electrode, wherein the second electrode is electrically connected to the third electrode to form a common electrical node; and electrically connecting a radio-frequency (RF) antenna to the common electrical node.