Patent application number | Description | Published |
20080266942 | Multiple level cell phase-change memory device having pre-reading operation resistance drift recovery, memory systems employing such devices and methods of reading memory devices - A memory device comprises a plurality of memory cells, each memory cell comprising a memory cell material that has an initial resistance that is determined in response to an applied programming current in a programming operation, the resistance of the memory cell varying from the initial resistance over a time period following the programming operation, and each memory cell being connected to a conduction line of the memory device that is used to apply the programming current to program the resistance of the corresponding memory cell in the programming operation and that is used to apply a read current to read the resistance of the corresponding memory cell in a read operation. A modification circuit modifies the resistance of a memory cell of the plurality of memory cells selected for a read operation to return its resistance to near the initial resistance prior to a read operation of the memory cell. | 10-30-2008 |
20090016100 | Multi-level phase change memory device and related methods - Provided are a phase change memory device and a reading method thereof. An example embodiment of a phase change memory device may include main cells programmed to have any one of a plurality of resistance states respectively corresponding to multi-bit data, reference cells programmed to have at least two respectively different resistance states among the resistance states each time the main cells are programmed, and a reference voltage generation circuit sensing the reference cells to generate reference voltages for identifying each of the resistance states. | 01-15-2009 |
20090034319 | PHASE CHANGE MEMORY DEVICE HAVING SCHOTTKY DIODE AND METHOD OF FABRICATING THE SAME - A phase change memory device includes wordlines extending along a direction on a semiconductor substrate. Low concentration semiconductor patterns are disposed on the wordlines. Node electrodes are disposed on the low concentration semiconductor patterns. Schottky diodes are disposed between the low concentration semiconductor patterns and the node electrodes. Phase change resistors are disposed on the node electrodes. | 02-05-2009 |
20090201721 | Phase change memory device and write method thereof - A phase change memory device and a write method thereof allow writing of both volatile and non-volatile data on the phase change memory device. The phase change memory device may be written by setting a write mode as one of a volatile write mode and a non-volatile write mode, and writing data as volatile or non-volatile by applying a write pulse corresponding to the write mode, wherein, when power is not supplied to the phase change memory device, the non-volatile data is retained and the volatile data is not retained. | 08-13-2009 |
20090230378 | RESISTIVE MEMORY DEVICES - Provided is a resistive memory device that can be integrated with a high integration density and method of forming the same. An insulating layer enclosing a resistive memory element and an insulating layer enclosing a conductive line connected with the resistive memory element have different stresses, hardness, porosity degrees, dielectric constant or heat conductivities. | 09-17-2009 |
20090258477 | METHODS OF FORMING PHASE-CHANGE MEMORY UNITS, AND METHODS OF MANUFACTURING PHASE-CHANGE MEMORY DEVICES USING THE SAME - In a method of forming a phase-change memory unit, a conductive layer is formed on a substrate having a trench. The conductive layer is planarized until the substrate is exposed to form a first electrode. A spacer partially covering the first electrode is formed. A phase-change material layer is formed on the first electrode and the second spacer. A second electrode is formed on the phase-change material layer. Reset/set currents of the phase-change memory unit may be reduced and deterioration of the phase-change material layer may be reduced and/or prevented. | 10-15-2009 |
20090285008 | MEMORY DEVICES WITH SELECTIVE PRE-WRITE VERIFICATION AND METHODS OF OPERATION THEREOF - A number of read cycles applied to a selected memory location of a memory device, such as a variable-resistance memory device, is monitored. Write data to be written to the selected memory location is received. Selective pre-write verifying and writing of the received write data to the selected memory location occurs based on the monitored number of read cycles. Selectively pre-write verifying and writing of the received write data may include, for example, writing received write data to the selected memory cell region without pre-write verification responsive to the monitored number of read cycles being greater than a predetermined number of read cycles | 11-19-2009 |
20100072453 | Phase-Changeable Fuse Elements and Memory Devices Containing Phase-Changeable Fuse Elements and Memory Cells Therein - Non-volatile memory devices include an array of phase-changeable memory cells, which have first phase-changeable material patterns therein, and at least one phase-changeable fuse element. This phase-changeable fuse element includes a second phase-changeable material pattern therein with a higher crystallization temperature relative to the first phase-changeable material patterns in the array of phase-changeable memory cells. This higher crystallization temperature may be greater than about 300° C. According to additional embodiments of the present invention, the at least one phase-changeable fuse element includes a composite of the second phase-changeable material pattern and a third phase-changeable material pattern, which is formed of the same material at the first phase-changeable material patterns. | 03-25-2010 |
20100220520 | Multi-bit phase change memory devices - A multi-bit phase change memory device including a phase change material having a plurality of crystalline phases. A non-volatile multi-bit phase change memory device may include a phase change material in a storage node, wherein the phase change material includes a binary or ternary compound sequentially having at least three crystalline phases having different resistance values according to an increase of temperature of the phase change material. | 09-02-2010 |
20110188304 | MULTIPLE LEVEL CELL PHASE-CHANGE MEMORY DEVICES HAVING PRE-READING OPERATION RESISTANCE DRIFT RECOVERY, MEMORY SYSTEMS EMPLOYING SUCH DEVICES AND METHODS OF READING MEMORY DEVICES - A memory device comprises a plurality of memory cells, each memory cell comprising a memory cell material that has an initial resistance that is determined in response to an applied programming current in a programming operation, the resistance of the memory cell varying from the initial resistance over a time period following the programming operation, and each memory cell being connected to a conduction line of the memory device that is used to apply the programming current to program the resistance of the corresponding memory cell in the programming operation and that is used to apply a read current to read the resistance of the corresponding memory cell in a read operation. A modification circuit modifies the resistance of a memory cell of the plurality of memory cells selected for a read operation to return its resistance to near the initial resistance prior to a read operation of the memory cell. | 08-04-2011 |