5089 results about "Memory cell" patented technology

In a preferred integrated circuit embodiment, a write-once memory array includes at least one test bit line which provides a respective test memory cell at the far end of each respective word line relative to its word line driver, and further includes at least one test word line which provides a respective test memory cell at the far end of each respective bit line relative to its bit line driver. An intra-layer short between word lines may be detected, such as during manufacturing testing, by biasing adjacent word lines to different voltages and detecting whether any leakage current flowing from one to another exceeds that normally accounted for by the memory cells and other known circuits. Intra-layer bit line shorts and inter-layer word line and bit line shorts may also be similarly detected. An "open" in a word line or bit line may be detected by trying to program the test memory cell at the far end of each such word line or bit line. If successfully programmed, the continuity of each word line and bit line is assured, and the programming circuitry for each word line and bit line is also known to be functional.

A memory device and method, such as a flash memory device and method, includes a memory having a plurality of nonvolatile memory cells for storing stored values of user data. The memory device and method includes a memory controller for controlling the memory. The memory controller includes an encoder for encoding user write data for storage of code values as the stored values in the memory. The encoder includes an inserter for insertion of an indicator as part of the stored values for use in determining when the stored values are or are not in an erased state. The memory controller includes a decoder for reading the stored values from the memory to form user read data values when the stored values are not in the erased state.

Methods of operating semiconductor memory devices with floating body transistors, using a silicon controlled rectifier principle are provided, as are semiconductor memory devices for performing such operations. A method of maintaining the data state of a semiconductor dynamic random access memory cell is provided, wherein the memory cell comprises a substrate being made of a material having a first conductivity type selected from p-type conductivity type and n-type conductivity type; a first region having a second conductivity type selected from the p-type and n-type conductivity types, the second conductivity type being different from the first conductivity type; a second region having the second conductivity type, the second region being spaced apart from the first region; a buried layer in the substrate below the first and second regions, spaced apart from the first and second regions and having the second conductivity type; a body region formed between the first and second regions and the buried layer, the body region having the first conductivity type; and a gate positioned between the first and second regions and adjacent the body region. The memory cell is configured to store a first data state which corresponds to a first charge in the body region in a first configuration, and a second data state which corresponds to a second charge in the body region in a second configuration. The method includes: providing the memory cell storing one of the first and second data states; and applying a positive voltage to a substrate terminal connected to the substrate beneath the buried layer, wherein when the body region is in the first state, the body region turns on a silicon controlled rectifier device of the cell and current flows through the device to maintain configuration of the memory cell in the first memory state, and wherein when the memory cell is in the second state, the body region does not turn on the silicon controlled rectifier device, current does not flow, and a blocking operation results, causing the body to maintain the second memory state.

A three dimensional (3D) semiconductor device includes; a vertical channel extending from a lower end proximate a substrate to an upper end and connecting a plurality of memory cells, and a cell array comprising the plurality of cells, wherein the cell array is arranged in a gate stack of layers having a stair-stepped structure disposed on the substrate. The gate stack includes a lower layer including a lower select line coupled to a lower non-memory transistor proximate the lower end, upper layers including conductive lines respectively coupled to an upper non-memory transistor proximate the upper end and connected as a single conductive piece to form an upper select line, and intermediate layers respectively including a word line and coupled to a cell transistor, wherein the intermediate layers are disposed between the lower select line and the upper select line.

Adaptive systems and methods that may help assure the reliability of data retrieved from memory cells are described herein. The systems may include a memory device including a plurality of memory cells, a data quality monitoring block, and an adaptive data encoding block, the data quality monitoring block and the adaptive data encoding block both being operatively coupled to the memory device. The data quality monitoring block may be configured to determine a quality value of a group of one or more memory cells included in the memory device, the determined quality value being indicative of a quality of the group of one or more memory cells. The adaptive data encoding block may be configured to select a coding scheme from a plurality of coding schemes to encode data to be written to the group of one or more memory cells in the memory device, the selection of the coding scheme being based at least in part on the determined quality value of the group of one or more memory cells.

A method, system and computer-readable medium are provided for reading information from a memory unit. A read instruction may be received to read information from a set of memory cells in the memory unit. A data structure storing sets of read thresholds may be searched for a set of read thresholds based on one or more characteristic value(s) of the set of memory cells. If the set of read thresholds is found, the set of memory cells may be read to execute the read instruction using the found set of read thresholds. The set of read thresholds may be thresholds which were previously used to successfully read a set of cells having the same or similar characteristic value(s).

A spin-transfer-torque magnetoresistive memory comprises apparatus and method of manufacturing a three terminal magnetoresistive memory element having highly conductive bottom electrodes overlaid on top of a SHE-metal layer in the regions outside of an MTJ stack. The memory cell comprises a bit line positioned adjacent to selected ones of the plurality of magnetoresistive memory elements to supply a reading current across the magnetoresistive element stack and two highly conductive bottom electrodes overlaid and electrically contacting on top of a SHE-metal layer in the outside of an MTJ region and to supply a bi-directional spin Hall effect recording current, and accordingly to switch the magnetization of the recording layer. Thus magnetization of a recording layer can be readily switched or reversed to the direction in accordance with a direction of a current along the SHE-metal layer by applying a low write current.

Non-volatile memory read operations compensate for floating gate coupling when the apparent threshold voltage of a memory cell may have shifted. A memory cell of interest can be read using a reference value based on a level of charge read from a neighboring memory cell. Misreading the neighboring cell may have greater effects in particular programming methodologies, and more specifically, when reading the neighboring cell for particular states or charge levels in those methodologies. In one embodiment, memory cells are programmed to create a wider margin between particular states where misreading a neighboring cell is more detrimental. Further, memory cells are read in one embodiment by compensating for floating gate coupling based on the state of a neighboring cell when reading at certain reference levels but not when reading at other reference levels, such as those where a wider margin has been created.

A technique of sampling, sensing, reading and/or determining the data state of a memory cell of a memory cell array (for example, a memory cell array having a plurality of memory cells which consist of an electrically floating body transistor). In one embodiment, the present inventions are directed to a memory cell, having an electrically floating body transistor, and/or a technique of reading the data state in such a memory cell. In this regard, the present inventions employ the intrinsic bipolar transistor current to read and/or determine the data state of the electrically floating body memory cell (for example, whether the electrically floating body memory cell is programmed in a State “0” and State “1”). During the read operation, the data state is determined primarily by or sensed substantially using the bipolar current responsive to the read control signals and significantly less by the interface channel current component, which is negligible relatively to the bipolar component. The bipolar transistor current may be very sensitive to the floating body potential due to the high gain of the intrinsic bipolar transistor. As such, the programming window obtainable with the bipolar reading technique may be considerably higher (for example, up two orders of magnitude higher) than the programming window employing a conventional reading technique (which is based primarily on the interface channel current component.

A memory cell for use in a memory array includes a storage element for storing a logical state of the memory cell, a write circuit and a read circuit. The write circuit is operative to selectively connect a first node of the storage element to at least a first write bit line in the memory array in response to a write signal for selectively writing the logical state of the memory cell. The read circuit includes a substantially high impedance input node connected to the storage element and an output node connectable to a read bit line of the memory array. The read circuit is configured to generate an output signal at the output node which is representative of the logical state of the storage element in response to a read signal applied to the read circuit. The memory cell is configured such that the write circuit is disabled during a read operation of the memory cell so as to substantially isolate the storage element from the first write bit line during the read operation. A strength of at least one transistor device in the storage element is separately optimized relative to a strength of at least one transistor device in the write circuit and/or the read circuit.

programmable resistance memory device includes: a semiconductor substrate; at least one cell array, in which memory cells are arranged, formed above the semiconductor substrate, each the memory cell having a stack structure of a programmable resistance element and an access element, the programmable resistance element storing a high resistance state or a low resistance state determined due to the polarity of voltage application in a non-volatile manner, the access element having such a resistance value in an off-state in a certain voltage range that is ten times or more as high as that in a select state; and a read/write circuit formed on the semiconductor substrate as underlying the cell array for data reading and data writing in communication with the cell array.

In a magnetic random access memory, a cross point cell array of memory cells is arranged in a matrix of columns and rows, and each of the memory cells has a magneto-resistance element. A column of dummy memory cells is provided, and each of the dummy memory cells has a magneto-resistance element. Word lines are provided for the rows of the memory cells and the dummy memory cells, respectively, and bit lines are provided for the columns of the memory cells, respectively. A dummy bit line is provided for the column of dummy memory cells. A read circuit is connected with the cross point cell array and the dummy bit line.

A method, system and computer program product for resetting a phase change memory cell having a memory cell threshold voltage is disclosed. The method includes reading a resistance of the memory cell. If the resistance is larger than a chosen resistance, the resetting of the memory cell ends. Otherwise, the method proceeds by applying a voltage, larger than the memory cell threshold voltage, to the bit line, and applying a voltage V_WL, larger than the access device threshold voltage, to the word line. The resistance of the memory cell is again read. If the resistance is larger than the chosen resistance, the resetting of the memory cell ends. Otherwise, the method proceeds by applying a voltage, larger than the memory cell threshold voltage, to the bit line, increasing voltage V_WL by a voltage ΔV and applying the increased voltage V_WL to the word line.

A memory device includes an array of NAND strings of memory cells. The device includes a plurality of stacks of conductive strips separated by insulating material, including at least a bottom plane of conductive strips, a plurality of intermediate planes of conductive strips, and a top plane of conductive strips. The device includes charge storage structures in interface regions at cross-points between side surfaces of the conductive strips in the plurality of intermediate planes in the stacks and inter-stack semiconductor body elements of a plurality of bit line structures. At least one reference line structure is arranged orthogonally over the stacks, including vertical conductive elements between the stacks in electrical communication with a reference conductor between the bottom plane of conductive strips and a substrate, and linking elements over the stacks connecting the vertical conductive elements. The vertical conductive elements have a higher conductivity than the semiconductor body elements.

A semiconductor memory device having a memory cell region and a peripheral circuit region, and a method of manufacturing such a semiconductor memory device, are proposed, in which trench grooves are formed to be shallow in the memory cell region in order to improve the yield, and trench grooves are formed to be deep in the high voltage transistor region of the peripheral circuit region, in particular in a high voltage transistor region thereof, in order to improve the element isolation withstand voltage. A plurality of memory cell transistors having an ONO layer 15 serving as a charge accumulating insulating layer are provided in the memory cell region, where element isolation grooves 6 for these memory cell transistors are narrow and shallow. Two types of transistors, one for high voltage and the other for low voltage, having gate insulating layers 16 or 17, which are different from the ONO layer 15 in the memory cell region, are provided in the peripheral circuit region, where at least element isolation grooves 23 for high voltage transistors are wide and deep. In this way, it is possible to improve the degree of integration and yield in the memory cell region, and secure withstand voltage in the peripheral circuit region.