Patent application number | Description | Published |
20080198645 | NONVOLATILE MEMORY DEVICE HAVING MEMORY AND REFERENCE CELLS - A nonvolatile memory device includes a stack-type memory cell array, a selection circuit and a read circuit. The memory cell array includes multiple memory cell layers and a reference cell layer, which are vertically laminated. Each of the memory cell layers includes multiple nonvolatile memory cells for storing data, and the reference cell layer includes multiple reference cells for storing reference data. The selection circuit selects a nonvolatile memory cell from the memory cell layers and at least one reference cell, corresponding to the selected nonvolatile memory cell, from the reference cell layer. The read circuit supplies a read bias to the selected nonvolatile memory cell and the selected reference cell corresponding to the selected nonvolatile memory cell, and reads data from the selected nonvolatile memory cell. | 08-21-2008 |
20080198646 | NONVOLATILE MEMORY DEVICE USING RESISTANCE MATERIAL - The present invention provides a nonvolatile memory device that uses a resistance material. The nonvolatile memory device includes: a stacked memory cell array having a plurality of memory cell layers stacked in a vertical direction, the stacked memory cell array having at least one memory cell group and at least one redundancy memory cell group; and a repair control circuit coupled to the stacked memory cell array, the repair control circuit configured to repair a defective one of the at least one memory cell group with a selected one of the at least one redundancy memory cell group. The features that enable repair improve the fabrication yield of the nonvolatile memory device. | 08-21-2008 |
20080212352 | MULTI-LAYER SEMICONDUCTOR MEMORY DEVICE COMPRISING ERROR CHECKING AND CORRECTION (ECC) ENGINE AND RELATED ECC METHOD - Embodiments of the invention provide a multi-layer semiconductor memory device and a related error checking and correction (ECC) method. The multi-layer semiconductor memory device includes first and second memory cell array layers, wherein the first memory cell array layer stores first payload data. The multi-layer semiconductor memory device also includes an ECC engine selectively connected to the second memory cell array layer and configured to receive the first payload data, generate first parity data corresponding to the first payload data, and store the first parity data exclusively in the second memory cell array layer. | 09-04-2008 |
20080273365 | NONVOLATILE MEMORY DEVICE HAVING TWIN MEMORY CELLS - A nonvolatile memory device includes multiple first bit lines extending in a first direction, multiple word lines formed on the first bit lines and extending in a second direction different from the first direction, and multiple second bit lines, formed on the word lines and extending in the first direction. The nonvoliative memory device also includes multiple twin memory cells, each of which includes a first memory cell coupled between a first bit line and a word line and a second memory cell coupled between the word line and a second bit line. The first and second memory cells store different data. | 11-06-2008 |
20100118601 | PHASE CHANGE RANDOM ACCESS MEMORY DEVICE - In a phase-change random access memory (PRAM) device, a write operation is performed by applying a set pulse to failed PRAM cells. The set pulse comprises a plurality of stages sequentially decreasing from a first current magnitude to a second current magnitude. The first current magnitude or the second current magnitude varies from one write loop to another. | 05-13-2010 |
20100246248 | MEMORY CELL ARRAY BIASING METHOD AND A SEMICONDUCTOR MEMORY DEVICE - A method of biasing a memory cell array during a data writing operation and a semiconductor memory device, in which 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 of a plurality of first lines and a second terminal of the memory cell is connected to a corresponding second line of a plurality of second lines; a bias circuit for biasing a selected second line of the second lines to a reference voltage and a non-selected second line to a first voltage; and a local word line address decoder applying the reference voltage or a pumping voltage corresponding to the first voltage to the bias circuit. | 09-30-2010 |
20100320433 | Variable Resistance Memory Device and Method of Manufacturing the Same - A variable resistance memory device includes a substrate, a plurality of active lines formed on the substrate, are uniformly separated, and extend in a first direction, a plurality of switching devices formed on the active lines and are separated from one another, a plurality of variable resistance devices respectively formed on and connected to the switching devices, a plurality of local bit lines formed on the variable resistance devices, are uniformly separated, extend in a second direction, and are connected to the variable resistance devices, a plurality of local word lines formed on the local bit lines, are uniformly separated, and extend in the first direction, a plurality of global bit lines formed on the local word lines, are uniformly separated, and extend in the second direction, and a plurality of global word lines formed on the global bit lines, are uniformly separated, and extend in the first direction. | 12-23-2010 |
20100329070 | Resistance Semiconductor Memory Device Having Three-Dimensional Stack and Word Line Decoding Method Thereof - A resistance semiconductor memory device of a three-dimensional stack structure, and a word line decoding method thereof, are provided. In the resistance semiconductor memory device of a three-dimensional stack structure, in which a plurality of word line layers and a plurality of bit line layers are disposed alternately and perpendicularly, and in which a plurality of memory cell layers are disposed between the word line layers and the bit line layers; the resistance semiconductor memory device includes a plurality of bit lines disposed on each of the bit line layers in a first direction as a length direction; a plurality of sub word lines disposed on each of the word line layers in a second direction as a length direction, intersected to the first direction; a plurality of memory cells disposed on the memory cell layers; and a plurality of main word lines individually disposed on a main word line layer specifically adapted over the bit line layers and the word line layers, in the second direction as a length direction, each one of the plurality of main word lines being shared by a predetermined number of sub word lines. An efficient word line decoding adequate to high integration can be achieved. | 12-30-2010 |
20110103134 | RESISTANCE RANDOM ACCESS MEMORY HAVING COMMON SOURCE LINE - A method writes data to a resistance random access memory (RRAM) memory cell through first and second write paths, and includes; applying a positive source voltage to a selected source line, applying a word line drive voltage to a selected word line, and applying a voltage at least twice the level of the positive source voltage to a selected bit line via the first write path when writing data having the first state in the memory cell, and applying a ground voltage to the selected bit line via the second write path when writing data having the second state in the memory cell. | 05-05-2011 |
20120182786 | BIDIRECTIONAL RESISTIVE MEMORY DEVICES USING SELECTIVE READ VOLTAGE POLARITY - A memory device includes a memory cell array including a plurality of memory cells, each including a bidirectional variable resistance element and an input/output circuit configured to determine a polarity for a read voltage to be applied to a selected memory cell among the plurality of memory cells and to apply the read voltage with the determined polarity to the selected memory cell. The input/output circuit may include a polarity determination circuit configured to determine the polarity responsive to a determination mode signal and a driver circuit configured to apply the read voltage with the determined polarity to the selected memory cell. | 07-19-2012 |
20130044538 | STACKED MRAM DEVICE AND MEMORY SYSTEM HAVING THE SAME - Provided is a stacked magnetic random access memory (MRAM) in which memory cell arrays having various characteristics or functions are included in memory cell layers. The stacked MRAM device includes a semiconductor substrate and at least one memory cell layers. The semiconductor substrate includes a first memory cell array. Each of the memory cell layers includes a memory cell array having a different function from the first memory cell array and is stacked on the first memory cell array. As a result, the stacked MRAM device has high density, high performance, and high reliability. | 02-21-2013 |
20130051124 | Resistive Memory Device and Test Systems and Methods for Testing the Same - A resistive memory device and a system and method for testing the resistive memory device are provided. The resistive memory device includes a plurality of bit lines comprising at least one dummy bit line to which a plurality of resistive memory cells are connected, a conducting wire connected to the dummy bit line, a first switching element positioned between the dummy bit line and an external device outside the resistive memory device, and a second switching element positioned between the conducting wire and the external device. Accordingly, the operational reliability of the resistive memory device may be increased. | 02-28-2013 |
20130064008 | DATA READ CIRCUIT, NONVOLATILE MEMORY DEVICE COMPRISING DATA READ CIRCUIT, AND METHOD OF READING DATA FROM NONVOLATILE MEMORY DEVICE - A nonvolatile memory device comprises a nonvolatile cell array comprising a memory cell and a reference cell, a clamping circuit electrically connected to the memory cell and configured to clamp a voltage applied to a data sensing line during a read operation, and a clamping voltage generation unit configured to generate a clamping voltage responsive to a first voltage having a level based on the reference cell, and to feed back the clamping voltage to the clamping circuit. | 03-14-2013 |
20130311717 | MAGNETIC RANDOM ACCESS MEMORY - A magnetic random access memory (MRAM), and a memory module, memory system including the same, and method for controlling the same are disclosed. The MRAM includes magnetic memory cells configured to change between at least two states according to a magnetization direction, and a mode register supporting a plurality of operational modes. | 11-21-2013 |
20130322162 | SEMICONDUCTOR MEMORY DEVICES AND RELATED METHODS OF OPERATION - A semiconductor memory device includes a cell array including one or more bank groups, where each of the one or more bank groups includes a plurality of banks and each of the plurality of banks includes a plurality of spin transfer torque magneto resistive random access memory (STT-MRAM) cells. The semiconductor memory device further includes a source voltage generating unit for applying a voltage to a source line connected to the each of the plurality of STT-MRAM cells, and a command decoder for decoding a command from an external source in order to perform read and write operations on the plurality of STT-MRAM cells. The command includes a combination of at least one signal of a row address strobe (RAS), a column address strobe (CAS), a chip selecting signal (CS), a write enable signal (WE), and a clock enable signal (CKE) | 12-05-2013 |
20140022836 | SEMICONDUCTOR MEMORY DEVICE HAVING RESISTIVE MEMORY CELLS AND METHOD OF TESTING THE SAME - A semiconductor memory device includes a memory cell array, a mode register set and a test circuit. The memory cell array includes a plurality of wordlines, a plurality of bitlines, and a plurality of spin-transfer torque magneto-resistive random access memory (STT-MRAM) cells, and each STT-MRAM cell disposed in a cross area of each wordline and bitline, and the STT-MRAM cell includes a magnetic tunnel junction (MTJ) element and a cell transistor. The MTJ element includes a free layer, a barrier layer and a pinned layer. A gate of the cell transistor is coupled to a wordline, a first electrode of the cell transistor is coupled to a bitline via the MTJ element, and a second electrode of the cell transistor is coupled to a source line. The mode register set is configured to set a test mode, and the test circuit is configured to perform a test operation by using the mode register set. | 01-23-2014 |
20140169069 | Resistive Memory Device, System Including the Same and Method of Reading Data in the Same - A resistive memory device includes a memory cell array, a memory interface and a read sensing circuit. The memory cell array includes a plurality of resistive memory cells coupled to a plurality of wordlines and a plurality of bitlines. The memory interface is configured to communicate with a memory controller. The read sensing circuit is coupled to the bitlines and includes at least one sensing node. The read sensing circuit performs a precharge operation to precharge the at least one sensing node between a first time point of receiving an active command through the memory interface and a second time point of receiving a read command through the memory interface, and senses data stored in the resistive memory cells to provide read data. | 06-19-2014 |