Abstract: A semiconductor memory device includes a plurality of cell array layers including a plurality of word lines extending in a first direction, a plurality of bit lines extending in a second direction that intersects the first direction, and a plurality of memory cells disposed at intersections of the word lines and the bit lines. Each of the word lines has a word line position, each of the bit lines has a bit line position, and each of the memory cells includes a variable resistance device in series with a diode. The cell array layers are arranged in layers in a third direction that is perpendicular to the first and second directions. The bit lines of each of the cell array layers having a same bit line position are connected to a common column selector transistor, or the word lines of the cell array layers having a same word line position are connected to a common word line driver.

Abstract: Disclosed is a nonvolatile memory device using a variable resistive element, and a data read circuit for use in variable resistive memory devices. More specifically, embodiments of the invention provide a data read circuit with one or more decoupling units to remove noise from one or more corresponding control signals. For instance, embodiments of the invention remove noise from a clamping control signal, a read bias control signal, and/or precharge signal. The disclosed decoupling units may be used alone or in any combination. Embodiments of the invention are beneficial because they can increase sensing margin and improve the reliability of read operations in memory devices with variable resistive elements.

Abstract: In a semiconductor memory device and method, resistive-change memory cells are provided, each including a plurality of control transistors formed on different layers and variable resistance devices comprising a resistive-change memory. Each resistive-change memory cell includes a plurality of control transistors formed on different layers, and a variable resistance device formed of a resistive-change memory. In one example, the number of the control transistors is two. The semiconductor memory device includes a global bit line; a plurality of local bit lines connected to or disconnected from the global bit line via local bit line selection circuits which correspond to the local bit lines, respectively; and a plurality of resistive-change memory cell groups storing data while being connected to the local bit lines, respectively.

Abstract: Provided are a nonvolatile memory and related method of programming same. The nonvolatile memory includes a memory cell array with a plurality of nonvolatile memory cells and a write circuit. The write circuit is configured to write first logic state data to a first group of memory cells during a first program operation using a first internally generated step-up voltage, and second logic state data to a second group of memory cells during a second program operation using an externally supplied step-up voltage.

Abstract: A non-volatile memory device using a variable resistive element is provided. The non-volatile memory device includes a memory cell array having a plurality of non-volatile memory cells, a first voltage generator generating a first voltage, a voltage pad receiving an external voltage that has a level higher than the first voltage, a sense amplifier supplied with the first voltage and reading data from the non-volatile memory cells selected from the memory cell array, and a write driver supplied with the external voltage and writing data to the non-volatile memory cells selected from the memory cell array.

Abstract: A semiconductor memory device includes a plurality of wordline driving circuits adapted to control the voltage level of a sub-wordline in response to a logic state of a global wordline and an address signal. The wordline driving circuit comprises first and second transistors configured to maintain the sub-wordline at a first voltage level when the global wordline and the address signal have a first logic state and at a second voltage level when the global wordline or the address signal have a second logic state.

Abstract: At least one embodiment includes a non-volatile memory cell array, a write buffer configured to store data being written into the non-volatile memory cell array, and a write unit configured to write data into the non-volatile memory cell array. The write unit is configured to perform writing of data such that each data will have reached a stable storage state in the non-volatile memory prior to being over-written in the write buffer.

Abstract: Provided is a nonvolatile memory using a resistance material. In embodiments of the invention, a PRAM is configured to apply a step-down voltage to wordlines during a standby mode. Aspects of the present invention thus provide a nonvolatile memory with reduced standby current. Additionally, embodiments of the invention allow for faster transition from a standby state to an active state.

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 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 phase-change cell memory device includes a plurality of phase-change memory cells, an address circuit, a write driver, and a write driver control circuit. The phase-change memory cells each include a volume of material that is programmable between amorphous and crystalline states. The address circuit selects at least one of the memory cells, and the write driver generates a reset pulse current to program a memory cell selected by the address circuit into the amorphous state, and a set pulse current to program the memory cell selected by the address circuit into the crystalline state. The write driver control circuit varies at least one of a pulse width and a pulse count of at least one of the reset and set pulse currents according to a load between the write driver and the memory cell selected by the address circuit.

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: An apparatus and operating method of a nonvolatile memory device having three-level nonvolatile memory cells is used to store more than one bit of data in a nonvolatile memory cell. In addition, the data can be selectively written through a write-verify operation, thereby improving write operation reliability. The operating method includes providing a memory cell array having first through third nonvolatile memory cells where each memory cell is capable of storing one among first data through third data corresponding to first through third resistance levels, respectively. Each of the resistance levels is different from one another. First and the third data are written to the first and third nonvolatile memory cells, respectively, during a first interval of a write operation. Second data is written to the second nonvolatile memory cell during a second interval of the write operation.

Abstract: Disclosed is a phase-changeable memory device and method of programming the same. The phase-changeable memory device includes memory cells each having multiple states, and a program pulse generator providing current pulses to the memory cells. The program pulse generator initializes a memory cell to a reset or set state by applying a first pulse thereto and thereafter provides a second pulse to program the memory cell to one of the multiple states. According to the invention, as a memory cell is programmed after being initialized to a reset or set state, it is possible to correctly program the memory cell without influence from the previous state of the memory cell.

Abstract: A resistance variable memory device includes a memory cell array, a sense amplifier circuit, and a column selection circuit. The memory cell array includes a plurality of block units and a plurality of word line drivers, where each of the block units is connected between adjacent word line drivers and includes a plurality of memory blocks. The sense amplifier circuit includes a plurality of sense amplifier units, where each of the sense amplifier units provides a read current to a corresponding block unit and includes a plurality of sense amplifiers. The column selection circuit is connected between the memory cell array and the sense amplifier circuit and selects at least one of the plurality of memory blocks in response to a column selection signal to apply the read current from the sense amplifier circuit to the selected memory block.

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: 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: 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 phase change memory device includes a memory cell array and a write driver circuit, and a column selection circuit. The memory cell array includes a plurality of block units each connected between a corresponding pair of word line drivers. The write driver circuit includes 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: 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.