Abstract: A semiconductor memory device and a layout structure of word line contacts, in which the semiconductor memory device includes an active region, a plurality of memory cells, and word line contacts. The active region is disposed in a first direction as a length direction on a semiconductor substrate and is used as a word line. The plurality of memory cells are disposed in the first direction on the active region and are each constructed of one variable resistance device and one diode device. In the word line contacts, at least one each is disposed between respective units, wherein each unit is constructed of predetermined numbers of memory cells on the active region. A bridge effect, such as a short-circuit between adjacent word lines, can be prevented or substantially reduced.

Abstract: A resistive memory device is provided. The resistive memory device includes word lines arranged in M rows, bit lines arranged in N columns, local source lines arranged in M/2 rows, and resistive memory cells arranged in M rows and N columns. Each of the resistive memory cells includes a resistance variable element having a first electrode connected to a corresponding bit line, and a cell transistor having a first terminal connected to a second electrode of the resistance variable element, a second terminal connected to a corresponding local source line, and a control terminal connected to a corresponding word line. The local source line is commonly connected to the second terminals of the cell transistors of the two neighboring rows.

Abstract: A multi-port phase change random access memory (PRAM) cell, includes a PRAM element including a phase change material, a writing controller configured to operate in correspondence with a writing word line, the writing controller connecting a writing bit line to the PRAM element, and a reading controller configured to operate in correspondence with a reading word line, the reading controller connecting the PRAM element to a reading bit line.

Abstract: A phase change random access memory on aspect includes a memory cell array block including a plurality of phase change memory cells, a column decoder, a row decoder, a column selector, and a write driver. The memory further includes a write boosting unit having a plurality of internal charge pumps which boost a first voltage to generate a write driving voltage which drives the write driver, where the number of internal charge pumps that are activated during a write operation is varied according to a number of phase change memory cells which are selected during the write operation. The memory still further includes a column boosting unit which boosts the first voltage to generate a column driving voltage which drives the column decoder, and a row boosting unit which boosts the first voltage to generate a row driving voltage which drives the row decoder.

Abstract: In a firing method of a phase change memory device and a phase change memory capable of effectively performing a firing operation, the phase change memory device includes a plurality of memory cell array blocks, a counter clock generation unit, a decoding unit, and a driving unit. Each memory cell array block has phase change memory cells. The counter clock generation unit outputs first through third counter clock signals in response to an external clock signal and a firing mode signal, wherein the first through third counter clock signals have different cycles. The decoding unit, in response to the first through third counter clock signals, outputs a block address which selects one of the plurality of memory cell array blocks, word line addresses which enable word lines of the selected memory cell array block, and a redundant word line address which enables a redundant word line of the selected memory cell array block.

Abstract: A PRAM and programming method are disclosed. The PRAM includes a memory cell array including a test cell, a write driver applying a program pulse and providing a program current to the memory cell array, a sense amplification and verification circuit reading data programmed in the memory cell array and performing a program verify operation on the data, and a program loop control unit storing program verification result for the test cell at each program loop during test operation and generating the program pulse according to the program verification result to control the start of the program loop during normal operation.

Abstract: According to an example embodiment, a CAM cell included in a CAM may include a phase change memory device, a connector, and/or a developer. The phase change memory device may be configured to store data. The phase change memory device may have a resistance that may be varied according to the logic level of the stored data. The connector may be configured to control writing data to the phase change memory device and reading data from the phase change memory device. The developer may be configured to control reading data from the phase change memory device in a search mode in which the data stored in the phase change memory device is compared to the search data.

Abstract: Provided is a method of testing a phase change random access memory (PRAM). The method may include providing a plurality of PRAM cells each coupled between each of a plurality of first lines and each of a plurality of second lines intersecting the first lines, selecting at least one of the plurality of first lines while deselecting the remaining first lines and the plurality of second lines, pre-charging the selected at least one of the plurality of first lines to a predetermined or given voltage level, and sensing a change in the voltage level of the selected first line while supplying a monitoring voltage to the selected first line.

Abstract: A method of operating a phase change random access memory (PRAM) device comprises performing a program operation to store data in selected PRAM cells of the device, wherein the program operation comprises a plurality of sequential program loops. The method further comprises suspending the program operation in the middle of the program operation, and after suspending the program operation, resuming the program operation in response to a resume command.

Abstract: In a nonvolatile memory device, a program operation is performed on a plurality of nonvolatile memory cells by programming data having a first logic state in a first group among a plurality of selected memory cells selected from the plurality of nonvolatile memory cells during a first program interval of the program operation, and thereafter, programming data having a second logic state different from the first logic state in a second group among the selected memory cells during a second program interval of the program operation after the first program interval.

Abstract: A method of biasing a memory cell array during a data writing operation and a semiconductor memory device are provided. The semiconductor memory device includes: a memory cell array including a plurality of memory cells in which a first terminal of a memory cell is connected to a corresponding first line among a plurality of first lines and a second terminal of a memory cell is connected to a corresponding second line among a plurality of second lines; and a bias circuit for biasing a selected second line to a first voltage and non-selected second lines to a second voltage.

Abstract: Phase-change memory devices are provided that include a plurality of phase-change memory cells and a reset pulse generation circuit configured to output a plurality of sequential reset pulses. Each sequential reset pulse is output to a corresponding one of a plurality of reset lines. A plurality of write driver circuits are coupled to corresponding phase change memory cells and to a corresponding one of the reset lines of the reset pulse generation circuit. Methods of programming phase-change memory devices using sequential reset control signals are also provided.

Abstract: A phase change memory device comprises a memory cell array and a write driver circuit, and a column selection circuit. The memory cell array comprises a plurality of block units each connected between a corresponding pair of word line drivers. The write driver circuit comprises a plurality of write driver units each comprising a plurality of write drivers adapted to provide respective programming currents to a corresponding block unit among the plurality of block units. The column selection circuit is connected between the memory cell array and the write driver circuit and is adapted to select at least one of the plurality of memory blocks in response to a column selection signal to provide corresponding programming currents to the at least one of the plurality of memory blocks.

Abstract: A phase change memory device includes a memory array including a plurality of phase change memory cells, each phase change memory cell including a phase change material and a diode, a plurality of column selection transistors connecting bit lines connected to the phase change memory cells to corresponding data lines, and a control node connecting the data lines to a sense amplifier unit. In a write operation mode, control voltages obtained by boosting a first voltage are respectively applied to the control node and gates of the column selection transistors, and a ground voltage is applied to a word line of a selected one of the phase change memory cells. In a standby mode, word lines and bit lines connected to the phase change memory cells of the memory array are maintained at the same voltage.

Abstract: A phase change memory device is disclosed. It includes a memory cell array including a plurality of memory cells programmed in relation to a phase change material, and a write driver circuit configured to provide a set current and a reset current to a selected memory cell. The write driver circuit includes a set current driver configured to provide the set current and a reset current driver configured to provide the reset current.

Abstract: A phase change memory device comprises a memory cell array and a write driver circuit. The memory cell array comprises a plurality of memory cells, and the write driver circuit comprises a set current driver and a reset current driver. The set current driver is adapted to provide a set current to a selected memory cell among the plurality of memory cells and the reset current driver is adapted to provide a reset current to a selected memory cell among the plurality of memory cells.

Abstract: A method for programming a phase-change memory array and circuit of a phase-change memory device, each having a plurality of phase-change memory cells, may enable all the phase-change memory cells therein to be changed or set at a set resistance state, and may reduce the time needed to change the phase-change memory array to the set resistance state. In the method, a set current pulse having first through nth stages may be applied to the cells of the array to change the cells to the set resistance state. A minimum current level of the set current pulse applied to the phase-change memory cells in any stage may be higher than a reference current level for the cells of the array. A given current level of the set current pulse may be sequentially reduced from stage to stage.

Abstract: A phase-change random access memory includes a memory block including a plurality of memory columns corresponding to the same column address and using different input/output paths; a redundancy memory block including a plurality of redundancy memory columns using different input/output paths; and an input/output controller repairing at least one of the plurality of memory columns using at least one of the plurality of redundancy memory columns, and controlling the number of memory columns simultaneously repaired using redundancy memory columns in response to an input/output repair mode control signal.

Abstract: The layout method for a semiconductor device includes locating a plurality of first bit line selection circuits at a first side of a variable resistive memory cell block, and locating a plurality of second bit line selection circuits at a second side of the variable resistive memory cell block opposite the first side. The method further includes connecting the first bit line selection circuits with respective odd-numbered local bit lines of the variable resistive memory cell block, and connecting the second bit line selection circuits with respective even-numbered local bit lines of the variable resistive memory cell block. The method still further includes selectively connecting respective odd-numbered local bit lines to a global bit line using the first bit line selection circuits, and selectively connecting respective even-numbered local bit lines to the global bit line using the second bit line selection circuits.

Abstract: A memory device includes a plurality of blocks, with each block having a respective array of memory cells and respective local word lines. The memory device also includes a respective switching device coupled between each local word line and a common voltage node. A global word line driver controls the respective switching devices to turn on for respective local word lines in a row across the blocks including an accessed memory cell. Thus, the common voltage node is in the current path of the accessed memory cell with minimized layout area and resistance of the current path.