Abstract: A phase-change memory device includes a first insulator having a hole therethrough, a first electrode that conforms at least partially to the hole, a phase-change material in electrical communication with the first electrode, and a second electrode in electrical communication with the phase-change material. When current is passed from the first electrode to the second electrode through the phase-change material, at least one of the first and second electrodes remains unreactive with the phase change material.

Abstract: A read circuit for reading at least one memory cell adapted to storing a logic value, the at least one memory cell including: a storage element made of a phase-change material; and an access element for coupling the storage element to the read circuit in response to a selection of the memory cell, the read circuit including: a sense current supply arrangement for supplying a sense current to the at least one memory cell; and at least one sense amplifier for determining the logic value stored in the memory cell on the basis of a voltage developing thereacross, the at least one sense amplifier comprising a voltage limiting circuit for limiting the voltage across the memory cell for preserving the stored logic value, wherein the voltage limiting circuit includes a current sinker for sinking a clamping current, which is subtracted from the sense current and depends on the stored logic value.

Abstract: A voltage derived from accessing a selected bit using one read current may be utilized to read a selected bit of an untriggered phase change memory after the read current is changed. As a result, different reference voltages may be used to sense the state of more resistive versus a less resistive selected cells. The resulting read window or margin may be improved in some embodiments.

Abstract: Input/Output circuitry employs thin-film switching devices to drive output signals from an integrated circuit to an external device and to receive input signals from an external device. Three terminal ovonic threshold switches (3T OTS) may be employed to drive input and output signals.

Abstract: In accordance with some embodiments, a phase change memory may be formed in which the thermal conductivity in the region outside the programmed volume of phase change material is reduced. This may reduce the power consumption of the resulting phase change memory. The reduction in power consumption may be achieved by forming distinct layers of phase change material that have little or no mixing between them outside the programmed volume. For example, in one embodiment, a diffusion barrier layer may be maintained between the two distinct phase change layers. In another embodiment, a face centered cubic chalcogenide structure may be utilized.

Abstract: A non-volatile memory device including a phase-change material, which has a low operating voltage and low power consumption, includes a lower electrode; a phase-change material layer formed on the lower electrode so as to be electrically connected to the lower electrode, wherein the phase-change material layer includes a phase-change material having a composition represented by SnXSbYTeZ or, alternatively with substitutions, in whole or in part, of silicon and/or indium for tin, arsenic and/or bismuth for antimony, and selenium for tellurium; and an upper electrode formed on the phase-change material layer so as to be electrically connected to the phase-change material layer. Here, 0.001?X?0.3, 0.001?Y?0.8, 0.1?Z?0.8, and X+Y+Z=1.

Abstract: A thin-film memory may include a thin-film transistor-free address decoder in conjunction with thin-film memory elements to yield an all-thin-film memory. Such a thin-film memory excludes all single-crystal electronic devices and may be formed, for example, on a low-cost substrate, such as fiberglass, glass or ceramic. The memory may be configured for operation with an external memory controller.

Abstract: A variable resistance material for memory applications. The material includes a base Ge—Sb—Te composition and further includes As-doping. The materials were included in variable resistance memory devices. Incorporation of As in the variable resistance composition led to a significant increase in the operational life of the device and, unexpectedly, did not reduce the programming speed of the device. In one embodiment, the composition includes at atomic concentration of Ge in the range from 7%-13%, an atomic concentration of Sb in the range from 50%-70%, an atomic concentration of Te in the range from 20%-30%, and an atomic concentration of As in the range from 2%-15%.

Abstract: A memory is configurable among a plurality of operational modes. The operational modes may dictate the number of storage levels to be associated with each cell within the memory's storage matrix.

Abstract: A multi-layer thin-film device includes thin film memory and thin film logic. The thin film memory may be programmable resistance memory, such as phase change memory, for example. The thin film logic may be complementary logic.

Abstract: A bidirectional memory cell includes an ovonic threshold switch (OTS) and a bidirectional memory element. The OTS is configured to select the bidirectional memory element and to prevent inadvertent accesses to the memory element.

Abstract: A phase change memory may include an ovonic threshold switch formed over an ovonic memory. In one embodiment, the switch includes a chalcogenide layer that overlaps an underlying electrode. Then, edge damage, due to etching the chalcogenide layer, may be isolated to reduce leakage current.

Abstract: A rewritable nonvolatile memory includes a test cell that is dedicated to testing the storage characteristics of other, similar, storage cells formed within the same integrated circuit memory. The test cell may be share the same structure and composition as storage cells and may be positioned proximate storage cells.

Abstract: A phase change memory may transition between two crystalline states. In one embodiment, the phase change material is a chalcogenide which transitions between face centered cubic and hexagonal states. Because these states are more stable, they are less prone to drift than the amorphous state conventionally utilized in phase change memories.

Abstract: Chalcogenide materials conventionally used in chalcogenide memory devices and ovonic threshold switches may exhibit a tendency called drift, wherein threshold voltage or resistance changes with time. By providing a compensating material which exhibits an opposing tendency, the drift may be compensated. The compensating material may be mixed into a chalcogenide, may be layered with chalcogenide, may be provided with a heater, or may be provided as part of an electrode in some embodiments. Both chalcogenide and non-chalcogenide compensating materials may be used.

Abstract: A minimal-duration current pulse is employed to program a programmable resistance memory to a high-resistance, RESET state. Although the duration and magnitude of RESET programming pulses in accordance with the principles of the present invention may vary depending, for example, upon the composition and structure of a cell, a method and apparatus in accordance with the principles of the present invention employs the briefest pulse practicable for a given cell or array of cells.

Abstract: A memory employs a low-level current source to access a phase change memory cell. The current source charges an access capacitor in order to store sufficient charge for an ensuing access. When a memory cell is accessed, charge stored on the capacitor is discharged through the phase change memory, supplying a current to the phase change memory cell that is sufficient for the intended access operation and greater than that provided directly by the current source.

Abstract: A voltage derived from accessing a selected bit using one read current may be utilized to read a selected bit of an untriggered phase change memory after the read current is changed. As a result, different reference voltages may be used to sense the state of more resistive versus a less resistive selected cells. The resulting read window or margin may be improved in some embodiments.

Abstract: A method and device for accomplishing transformation of a switching material from a resistive state to a conductive state. The method utilizes a non-electrical source of energy to effect the switching transformation. The switching material may be a chalcogenide switching material, where the non-electrical source of energy initiates switching by liberating lone pair electrons from bound states of chalcogen atoms. The liberated lone pair electrons form a conductive filament having the characteristics of a solid state plasma to permit high current densities to pass through the switching material. The device includes a switching material with electrical contacts and may be interconnected with other elements in a circuit to regulate electrical communication therebetween.

Abstract: A read current high enough to threshold a phase change memory element may be used to read the element without thresholding the memory element. The higher current may improve performance in some cases. The memory element does not threshold because the element is read and the current stopped prior to triggering the memory element.