Abstract: A nonvolatile memory device comprises a first voltage generation unit, a second voltage generation unit, a first circuit block, and a discharge unit. The first voltage generation unit generates a first voltage with a first magnitude. The second voltage generation unit generates a second voltage with a second magnitude greater than the first magnitude. The first circuit block selectively receives the first voltage or the second voltage through an input node. The discharge unit discharges the input node between a time point where the input node has been charged with the second voltage and a time point where the input node receives the first voltage.

Abstract: A semiconductor memory device includes: phase-change memory cells whose states change to a set resistance state or a reset resistance state in response to an applied current pulse; a set pulse driving circuit outputting a set current pulse having first through n-th stages in response to a first control signal and a set control signals wherein current amounts of the first through n-th stages are sequentially reduced and are all greater than a reference current amount; a reset pulse driving circuit outputting a reset current pulse in response to a second control signal; a pull-down device activating the set pulse driving circuit and the reset pulse driving circuit in response to a third control signal; and a write driver control circuit outputting the first through third control signals in response to write data, a set pulse width control signal, and a reset pulse width control signal.

Abstract: Provided are a phase-change memory device and method that maintains a resistance of a phase-change material in a set state within a constant resistance range; In the method, data is provided to a first phase-change memory cell and then it is first determined whether data stored in the first phase-change memory cell and the data provided to the first phase-change memory cell are identical.

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: A phase change memory device for use in a burst read operation and a data reading method are provided. The memory device includes a plurality of bit lines and a plurality of word lines. A memory cell array block has a plurality of phase change memory cells that are connected to cross points of the plurality of bit lines and the plurality of word lines. A sense amplifier block is connected to corresponding bit lines, and latches data of memory cells connected to the same word line simultaneously during a burst read operation, and then provides the latched data in response to a column address.

Abstract: A method of performing a program-suspend-read operation in a PRAM device comprises programming a write block comprising N unit program blocks in response to a program operation request, and suspending the program operation after programming M unit program blocks, where M is less than N, in response to a read operation request. The method further comprises executing the requested read operation, and then resuming the programming of the write data block and programming (N?M) remaining unit program blocks.

Abstract: A semiconductor memory device includes: phase-change memory cells whose states change to a set resistance state or a reset resistance state in response to an applied current pulse; a set pulse driving circuit outputting a set current pulse having first through n-th stages in response to a first control signal and a set control signal, wherein current amounts of the first through n-th stages are sequentially reduced and are all greater than a reference current amount; a reset pulse driving circuit outputting a reset current pulse in response to a second control signal; a pull-down device activating the set pulse driving circuit and the reset pulse driving circuit in response to a third control signal; and a write driver control circuit outputting the first through third control signals in response to write data, a set pulse width control signal, and a reset pulse width control signal.

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: A phase change memory device includes a memory cell having a phase change material, a write driver adapted to supply a program current to the memory cell during a programming interval, and a pump circuit adapted to enhance a current supply capacity of the write driver during the programming interval. The pump circuit is activated prior to the programming interval in response to an external control signal.

Abstract: Programming phase-change memory devices and driver circuits for programming phase-change memory devices are provided that control an amount of current supplied to a phase-change material of the phase-change memory device based on a measure of resistance of the phase-change material during programming of the phase-change memory device. Such control may be based on detected voltage or current. The amount of current supplied to the phase-change material may be increased until the measured voltage level changes with respect to a reference voltage value and the current maintained constant if the measured voltage level has changed with respect to the reference voltage value. The change of the measured voltage level with respect to the reference voltage may be the measured voltage level falling below the reference voltage value.

Abstract: A phase change memory device of one aspect includes a memory array including a plurality of phase change memory cells, a write boosting circuit, and a write driver. The write boosting circuit boosts a first voltage and outputs a first control voltage in response to a control signal in a first operation mode, and boosts the first voltage and outputs a second control voltage in response to the control signal in a second operation mode and a third operation mode. The write driver is driven by the first control voltage in the first operation mode and writes data to a selected memory cell of the memory array.

Abstract: A line layout structure and method in a semiconductor memory device having a hierarchical structure are provided. In a semiconductor memory device having a global word line and a local word line, and a global bit line and a local bit line, and individually disposing all of the global word line, the local word line, the global bit line and the local bit line at conductive layers among at least three layers; at least two of the global word line, the local word line, the global bit line and the local bit line are together disposed in parallel on one conductive layer. Signal lines constituting a semiconductor memory device are disposed in a hierarchical structure, whereby a semiconductor memory device advantageously having high integration, high speed and high performance may be obtained.

Abstract: In one aspect, a semiconductor memory device includes a plurality of phase-change memory cells which are programmed according to a write current applied to the phase-change memory cells, a voltage boosting circuit which receives a first voltage and outputs a boosted voltage which is greater than the first voltage, and a write driver which receives the boosted voltage and which generates the write current from the boosted voltage. In another aspect, the write driver generates the write current corresponding to one of a set current pulse and a reset current pulse, and at least one of the set current pulse and the reset current pulse is gradually increased.

Abstract: A method of programming a memory array including a plurality of memory cells is provided. The memory cells may include phase-change memory elements. In one aspect, the method includes applying in succession first through nth current pulses to each of the memory cells to be programmed to a first state (e.g., a crystalline state), where a current amplitude of the first through nth current pulses decreases with each successive pulse, and where a pulse duration of the first through nth current pulses increases with each successive pulse.

Abstract: A semiconductor memory device of one aspect includes a memory cell block including n global word lines, and corresponding m sub word lines for each of the n global word lines, where n and m are natural numbers. The memory device further includes a plurality of word line driving circuits which respectively control a voltage of the sub word lines according to a logic level of each corresponding global word line and inputted address signals, and a plurality of control circuits which transmit the address signals to the word line driving circuits or interrupt transmission of the address signals according to the logic level of the global word line. Each of the word line driving circuits includes a first transistor which maintains the voltage of the respective sub word line at a first voltage and a second transistor which maintains the voltage of the sub word line at the first voltage or a second voltage.

Abstract: Phase change memory devices having cell diodes and related methods are provided, where the phase change memory devices include a semiconductor substrate of a first conductivity type and a plurality of parallel word lines disposed on the semiconductor substrate, the word lines have a second conductivity type different from the first conductivity type and have substantially flat top surfaces, a plurality of first semiconductor patterns are one-dimensionally arrayed on each word line along a length direction of the word line, the first semiconductor patterns have the first conductivity type or the second conductivity type, second semiconductor patterns having the first conductivity type are stacked on the first semiconductor patterns, an insulating layer is provided on the substrate having the second semiconductor patterns, the insulating layer fills gap regions between the word lines, gap regions between the first semiconductor patterns and gap regions between the second semiconductor patterns, a plurality of p

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: A semiconductor memory device includes: phase-change memory cells whose states change to a set resistance state or a reset resistance state in response to an applied current pulse; a set pulse driving circuit outputting a set current pulse having first through n-th stages in response to a first control signal and a set control signal, wherein current amounts of the first through n-th stages are sequentially reduced and are all greater than a reference current amount; a reset pulse driving circuit outputting a reset current pulse in response to a second control signal; a pull-down device activating the set pulse driving circuit and the reset pulse driving circuit in response to a third control signal; and a write driver control circuit outputting the first through third control signals in response to write data, a set pulse width control signal, and a reset pulse width control signal.

Abstract: A phase change memory device for use in a burst read operation and a data reading method are provided. The memory device includes a plurality of bit lines and a plurality of word lines. A memory cell array block has a plurality of phase change memory cells that are connected to cross points of the plurality of bit lines and the plurality of word lines. A sense amplifier block is connected to corresponding bit lines, and latches data of memory cells connected to the same word line simultaneously during a burst read operation, and then provides the latched data in response to a column address.

Abstract: Programming phase-change memory devices and driver circuits for programming phase-change memory devices are provided that control an amount of current supplied to a phase-change material of the phase-change memory device based on a measure of resistance of the phase-change material during programming of the phase-change memory device. Such control may be based on detected voltage or current. The amount of current supplied to the phase-change material may be increased until the measured voltage level changes with respect to a reference voltage value and the current maintained constant if the measured voltage level has changed with respect to the reference voltage value. The change of the measured voltage level with respect to the reference voltage may be the measured voltage level falling below the reference voltage value.