The switching device includes three terminals including an inner surface, an oxide layer on the inner surface of the third terminal, and a chalcogenide pillar extending through the oxide layer and the third terminal, the pillar being in electrical communication with the first terminal and the second terminal, wherein the voltage difference between the first terminal and the second terminal changes the channel from a first state to a second state when a threshold voltage between the first terminal and the second terminal is exceeded, the threshold voltage being dependent on temperature. The third terminal is resistive and receives a control signal to apply heat to the pillar and modulate the threshold voltage. The switching device can be used to select the memory stack through the bitline and provide a nearly limitless current based on the threshold switching conduction providing avalanche current conduction through the switching device.

A radio frequency (RF) switch includes a phase-change material (PCM), a heating element underlying an active segment of the PCM and extending outward and transverse to the PCM, a capacitive RF terminal, and an ohmic RF terminal. The capacitive RF terminal can include a first trench metal liner situated on a first passive segment of the PCM, and a dielectric liner separating the first trench metal liner from a first trench metal plug. The ohmic RF terminal can include a second trench metal liner situated on a second passive segment of the PCM, and a second trench metal plug ohmically connected to the second trench metal liner. Alternatively, the capacitive RF terminal and the ohmic RF terminal can include lower metal portions and upper metal portions. A MIM capacitor can be formed by the upper metal portion of the capacitive RF terminal, an insulator, and a patterned top plate.

Methods and structures for fabricating a semiconductor device that includes a reduced programming current phase change memory (PCM) are provided. The method includes forming a bottom electrode. The method further includes forming a PCM and forming a conductive bridge filament in a dielectric to serve as a heater for the PCM. The method also includes forming a top electrode.

A method of integrating a phase change switch (PCS) into a Bipolar (Bi)/Complementary Metal Oxide Semiconductor (CMOS) (BiCMOS) process, comprises providing a base structure including BiCMOS circuitry on a semiconductor substrate, and forming on the base structure a dielectric contact window layer having metal through-plugs that contact the BiCMOS circuitry. The method includes constructing the PCS on the contact window layer. The PCS includes: a phase change region, between ohmic contacts on the phase change region, to operate as a switch controlled by heat. The method further includes forming, on the contact window layer and the PCS, a stack of alternating patterned metal layers and dielectric layers that interconnect the patterned metal layers, such that the stack connects a first of the ohmic contacts to the BiCMOS circuitry and provides connections to a second of the ohmic contacts and to the resistive heater.

A phase-change material (PCM) switching device includes: a base dielectric layer over a semiconductor substrate; a first heater element disposed on the base dielectric layer, the first heater element comprising a first metal element characterized by a first coefficient of thermal expansion (CTE); a second heater element disposed on the first heater element, the second heater element comprising a second metal element characterized by a second CTE larger than the first CTE; a first metal pad and a second metal pad; and a PCM region comprising a PCM operable to switch between an amorphous state and a crystalline state in response to heat generated by the first heater element and the second heater element, wherein the PCM region is disposed above a top surface of the second heater element, and an air gap surrounds the first heater element and the second heater element from three sides.

A semiconductor structure comprising a first electrode, a second electrode, a phase-change material (PCM) line in contact with and positioned between the first electrode and the second electrode, at least two heater lines positioned between the first electrode and the second electrode, and an isolation layer positioned between the PCM line and the at least two heater lines is provided. A method of forming a semiconductor structure is provided, the method including forming a dielectric isolation layer having a planar top surface over a substrate, forming at least two heater lines over the planar top surface, forming at least one heater-capping dielectric plate over the at least two heater lines, forming a phase-change material (PCM) line over the at least one heater-capping dielectric plate, forming a first electrode and a second electrode, and forming a PCM-capping dielectric plate over the PCM line.

A method for fabricating a semiconductor device includes forming first contacts to a heater for programming, and forming second contacts to a phase-change material layer for resistance readout. The phase-change material layer is formed in proximity to the heater, and the first contacts are electrically isolated from the second contacts to provide separate programming and resistance readout control.

A semiconductor device includes a base structure of a memory device including a first electrode, first dielectric material having a non-uniform etch rate disposed on the base structure, a via within the first dielectric material, and a ring heater within the via on the first electrode. The ring heater has a geometry based on a shape of the via that produces a resistance gradient.

Phase change memory devices and methods of forming the same include forming a fin structure from a first material. A phase change memory cell is formed around the fin structure, using a phase change material that includes two solid state phases at an operational temperature.

A non-volatile adjustable phase shifter is coupled to a transceiver in a wireless communication device. The non-volatile adjustable phase shifter includes a non-volatile radio frequency (RF) switch. In one implementation, the non-volatile RF switch is a phase-change material (PCM) RF switch. In one approach, the non-volatile adjustable phase shifter includes a selectable transmission delay arm and a selectable transmission reference arm. A phase shift caused by the non-volatile adjustable phase shifter is adjusted when the non-volatile RF switch engages with or disengages from the selectable transmission delay arm. In another approach, the non-volatile adjustable phase shifter includes a selectable impedance element. A phase shift caused by the non-volatile adjustable phase shifter is adjusted when the non-volatile RF switch engages with or disengages from the selectable impedance element. In either approach, the phase shift changes a phase of RF signals being transmitted from or received by the transceiver.