摘要:
A bit scan circuit includes N scan blocks corresponding with an N-bit string of binary data. The string is scanned using an input clock signal to count the number of bits having a predetermined binary value. Each scan block includes a single latch to transfer the corresponding bit and to indicate reset. The scan blocks are organized into groups. Each group is enabled by a corresponding token signal. The token signal for each group is asserted after each preceding scan block indicates a pass value. When enabled by its token signal, the first scan block in a group is reset by a first clock signal. A second scan block in the group is enabled for reset after the first scan block indicates the pass value. The second scan block in the group is reset by a second clock signal having pulses that precede corresponding pulses from the first clock signal.
摘要:
Methods for operating a non-volatile memory that includes a plurality of memory arrays in which each memory array of the plurality of memory arrays may independently perform a SET operation, a RESET operation, or a read operation are described. The ability to independently SET or RESET memory arrays allows a SET operation to be performed on a first set of memory cells within a first memory array at the same time as a RESET operation is performed on a second set of memory cells within a second memory array. In some cases, the first memory array may be associated with a first memory bay and the second memory array may be associated with a second memory bay. Each memory bay may include a memory array, read/write circuits, and control circuitry for determining memory cell groupings and programming memory cells within the memory array based on the memory cell groupings.
摘要:
Methods for forming a dual gate structure for a vertical TFT are described. The dual gate structure may be formed by performing a first etching process that includes forming a first set of trenches by etching a first set of oxide pillars to a first depth and forming a second set of trenches by etching a second set of oxide pillars to a second depth higher than the first depth, forming a first set of gate structures within the first set of trenches, forming a second set of gate structures within the second set of trenches, performing a second etching process that includes forming a third set of trenches by etching the first set of gate structures from a second initial depth to a third depth and forming a fourth set of trenches by etching the second set of gate structures to a fourth depth higher than the third depth.
摘要:
Methods for reducing location-based variations in the switching characteristics of memory cells within a memory array are described. In some cases, the resistance of an embedded resistor within each memory cell may be set to reduce the overall variation in series resistances for the memory cells within a memory array. For example, embedded resistors associated with far-far bits may be set to a lower resistance than embedded resistors associated with near-near bits. An embedded resistor may comprise a layer of polysilicon within a memory cell. Selective ion implantation may be used to reduce the embedded resistor resistance for memory cells within a particular region of the memory array and to form two or more different sets of embedded resistors within the memory array.
摘要:
Embodiments of the invention generally include a method of forming a nonvolatile memory device that contains a resistive switching memory element that has an improved device switching performance and lifetime, due to the addition of a current limiting component disposed therein. In one embodiment, the current limiting component comprises at least one layer of resistive material that is configured to improve the switching performance and lifetime of the formed resistive switching memory element. The electrical properties of the formed current limiting layer, or resistive layer, are configured to lower the current flow through the variable resistance layer during the logic state programming steps (i.e., “set” and “reset” steps) by adding a fixed series resistance in the formed resistive switching memory element found in the nonvolatile memory device. Typically, resistive switching memory elements may be formed as part of a high-capacity nonvolatile memory integrated circuit, which can be used in various electronic devices, such as digital cameras, mobile telephones, handheld computers, and music players.
摘要:
In a 3D memory with vertical local bit lines, each local bit line is switchably connected to a node on a global bit line having first and second ends, the local bit line voltage is maintained at a predetermined reference level in spite of being driven by a bit line driver from a first end of the global bit line that constitutes variable circuit path length and circuit serial resistance. This is accomplished by a feedback voltage regulator comprising a voltage clamp at the first end of the global bit line controlled by a bit line voltage comparator at the second end of the global bit line. The comparator compares the bit line voltage sensed from the second end with the predetermined reference level and outputs a control voltage to control the voltage clamp In this way the voltage at the local bit line is regulated at the reference voltage.
摘要:
A metal silicon oxide barrier layer between a nitride electrode containing the same metal and an oxide variable-resistance layer in a ReRAM cell prevents the metal from diffusing into the variable-resistance layer and prevents oxygen from diffusing into and oxidizing the electrode. Compound oxides of the same metal and silicon with varying stoichiometries and metal/silicon ratios may optionally replace part or all of the variable-resistance layer, a defect-reservoir layer, or both. The metal nitride electrode may include a metal silicon nitride current-limiting portion. Optionally, all the layers sharing the common metal may be formed in-situ as part of a single unit process, such as atomic layer deposition.
摘要:
Methods for determining memory cell states during a read operation using a detection scheme that reduces the area of detection circuitry for detecting the states of the memory cells by time multiplexing the use of portions of the detection circuitry are described. The read operation may include a precharge phase, a sensing phase, and a detection phase. In some embodiments, a first bit line and a second bit line may be precharged to a read voltage in parallel, and then sensing and/or detection of selected memory cells corresponding with the first bit line and the second bit line may be performed serially using the same detection circuitry by time multiplexing the use of the detection circuitry. In some cases, the time multiplexed detection circuitry may be used for detecting two or more states corresponding with two or more memory cells being sensed during a read operation.
摘要:
Methods for reducing leakage currents through unselected memory cells of a memory array during a memory operation are described. In some cases, the leakage currents through the unselected memory cells of the memory array may be reduced by setting an adjustable resistance bit line structure connected to the unselected memory cells into a non-conducting state. The adjustable resistance bit line structure may comprise a bit line structure in which the resistance of an intrinsic (or near intrinsic) polysilicon portion of the bit line structure may be adjusted via an application of a voltage to a select gate portion of the bit line structure that is not directly connected to the intrinsic polysilicon portion. The intrinsic polysilicon portion may be set into a conducting state or a non-conducting state based on the voltage applied to the select gate portion.
摘要:
A three-dimensional memory is formed as an array of memory elements across multiple layers positioned at different distances above a semiconductor substrate. Cylindrical stacks of memory elements are formed where a cylindrical opening has read/write material deposited along its wall, and a cylindrical vertical bit line formed along its central axis. Memory elements formed on either side of such a cylinder may include sheet electrodes that extend into the read/write material.