A semiconductor memory includes a substrate including a cell region, first and second peripheral circuit regions disposed on two sides of the cell region; first lines extending across the cell region and a first peripheral circuit region; second lines disposed over the first lines and extending across the cell region and the second peripheral circuit region; a contact plug in the second peripheral circuit region and connected to the second line; third lines disposed over the second lines and respectively overlapping the second lines; and first memory cells disposed in the cell region and located at intersections of the first lines and the second lines between the first lines and the second lines, wherein portions of the third line located in the cell region and over the contact plug contact the second line, and part of a remainder of the third line is spaced apart from the second line.

According to some embodiments of the present invention a phase change device (PCD) has a first and second semiconductor layer. The first semiconductor layer made of a first semiconductor material and has a first semiconductor thickness, a first interface surface, and a first electrode surface. The first interface surface and first electrode surface are on opposite sides of the first semiconductor layer. The first semiconductor material can transition between a first amorphous state and a first crystalline state at one or more first conditions. The second semiconductor layer is made of a second semiconductor material and has a second semiconductor thickness, a second interface surface, and a second electrode surface. The second interface surface and second electrode surface are on opposite sides of the second semiconductor layer. The first interface surface and the second interface surface are in electrical, physical, and chemical contact with one another at an interface. The second semiconductor material can transition between a second amorphous state and a second crystalline state at one or more second conditions. A first electrode in physical and electrical contact with the first electrode surface of the first semiconductor layer and a second electrode in physical and electrical contact with the second electrode surface of the second semiconductor layer. The first conditions and second conditions are different. Therefore, in some embodiments, the first and second semiconductor materials can be in different amorphous and/or crystalline states. The layers can have split amorphous/crystalline states. By controlling how the layers are split, the PCD can be in different resistive states.

A security key associated with a plurality of programmable switches included in an integrated circuit is received. The plurality of programmable switches are set causing the plurality of programmable switches to be conductive. Reset pulses are applied to a first set of programmable switches included in the plurality of programmable switches based on the received security key.

A resistive random access memory and a manufacture method thereof are provided. The resistive random access memory includes: a first electrode, a second electrode, a resistive layer between the first electrode and the second electrode, and at least one thermal enhanced layer; the thermal enhanced layer is adjacent to the resistive layer, and a thermal conductivity of the thermal enhanced layer is less than a thermal conductivity of the first electrode and a thermal conductivity of the second electrode.

According to some embodiments of the present invention a phase change device (PCD) has a first and second semiconductor layer. The first semiconductor layer made of a first semiconductor material and has a first semiconductor thickness, a first interface surface, and a first electrode surface. The first interface surface and first electrode surface are on opposite sides of the first semiconductor layer. The first semiconductor material can transition between a first amorphous state and a first crystalline state at one or more first conditions. The second semiconductor layer is made of a second semiconductor material and has a second semiconductor thickness, a second interface surface, and a second electrode surface. The second interface surface and second electrode surface are on opposite sides of the second semiconductor layer. The first interface surface and the second interface surface are in electrical, physical, and chemical contact with one another at an interface. The second semiconductor material can transition between a second amorphous state and a second crystalline state at one or more second conditions. A first electrode in physical and electrical contact with the first electrode surface of the first semiconductor layer and a second electrode in physical and electrical contact with the second electrode surface of the second semiconductor layer. The first conditions and second conditions are different. Therefore, in some embodiments, the first and second semiconductor materials can be in different amorphous and/or crystalline states. The layers can have split amorphous/crystalline states. By controlling how the layers are split, the PCD can be in different resistive states.

Methods, systems, and devices related to a memory device with a thermal barrier are described. The thermal barrier (e.g., a low density thermal barrier) may be positioned between an access line (e.g., a digit line or a word line) and a cell component. The thermal barrier may be formed on the surface of a barrier material by applying a plasma treatment to the barrier material. The thermal barrier may have a lower density than the barrier material and may be configured to thermally insulate the cell component from thermal energy generated in the memory device, among other benefits.

A method is presented for enabling heat dissipation in resistive random access memory (RRAM) devices. The method includes forming a first thermal conducting layer over a bottom electrode, depositing a metal oxide liner over the first thermal conducting layer, forming a second thermal conducting layer over the metal oxide liner, recessing the second thermal conducting layer to expose the first thermal conducting layer, and forming a top electrode in direct contact with the first and second thermal conducting layers.

A method is presented for enabling heat dissipation in resistive random access memory (RRAM) devices. The method includes forming a first thermal conducting layer over a bottom electrode, depositing a metal oxide liner over the first thermal conducting layer, forming a second thermal conducting layer over the metal oxide liner, recessing the second thermal conducting layer to expose the first thermal conducting layer, and forming a top electrode in direct contact with the first and second thermal conducting layers.

A radio frequency (RF) device includes a phase-change material (PCM) situated over a sheet of thermally conductive and electrically insulating material, a heating element situated under the sheet of thermally conductive and electrically insulating material, and an input/output terminal situated over the PCM. The heating element is situated in a dielectric. A heat spreader is situated under the dielectric and over a substrate. Metal interconnect layers can be situated under and/or over the PCM, with the substrate situated below the metal interconnect layers.

Circuits and methods that enable stacking of phase change material (PCM) switches and that accommodate variations in the resistance of the resistive heater(s) of such switches. Stacking is enabled by providing isolation switches for the resistive heater(s) in a PCM switch to reduce parasitic capacitance caused by the proximity of the resistive heater(s) to the PCM region of a PCM switch. Variations in the resistance of the resistive heater(s) of a PCM switch are mitigated or eliminated by sensing the actual resistance of the resistive heater(s) and then determining a suitable adjusted electrical pulse profile for the resistive heater(s) that generates a precise thermal pulse to the PCM region, thereby reliably achieving a desired switch state while extending the life of the resistive heater(s) and the phase-change material.