Abstract: An erase process for a group of non-volatile memory cells comprises applying doses of erasing to the group and performing erase verify between pairs of successive doses of erasing. The time needed to complete the erase process can be reduced by optimizing the order of performing erase verify. For example, erase verify can be performed by separately performing erase verify for multiple portions of the group in order from previously determined slowest erasing portion of the group to previously determined fastest erasing portion of the group, and aborting the performing of erase verify prior to completion of erase verify for all of the portions of the group in response to a number erase errors exceeding a limit.

Abstract: In a memory array with a cross-point structure, at each cross-point junction a programmable resistive memory element, such as an MRAM memory cell, is connected in series with a threshold switching selector, such as an ovonic threshold switch. The threshold switching selector switches to a conducting state when a voltage above a threshold voltage is applied. When powered down for extended periods, the threshold voltage can drift upward. If the drift is excessive, this can make the memory cell difficult to access and can disturb stored data values when accessed. Techniques are presented to determine whether excessive voltage threshold drift may have occurred, including a read based test and a time based test. Techniques are also presented for initializing a cross-point array, for both first fire and cold start, by using voltage levels shifted from half-select voltage levels used in a standard memory access.

Abstract: A three dimensional non-volatile memory structure includes word lines connected to non-volatile memory cells arranged in blocks. A plurality of word line switches are connected to the word lines and one or more sources of voltage. The word line switches are arranged in groups of X word line switches such that each group of X word line switches is positioned in a line under Y blocks of non-volatile memory cells and has a length that is equal to the width of the Y blocks of non-volatile memory cells, where X>Y.

Abstract: A system has been described that performs differential temperature compensation based on a differential between the temperature at time of programming and temperature at time of reading for a set of data. Differential temperature compensation is useful for bulk programming/reading (e.g., many pages of data) and/or programming/reading super pages of data (multiple pages residing on different memory die).

Abstract: A non-volatile memory combines a hard bit and a soft bit read into a single, efficient soft sense sequence by using two sense per state level to improve read time efficiency. Rather than a standard hard bit read, where two soft bit reads are performed, offset above and below the hard bit read value, the hard bit read is shifted so that it reliable senses one state but less reliably senses the other state and soft bit data is only determined for the less reliably sensed state. This reduces the amount of soft bit data. The efficient soft sense sequence can be used as a default read mode, providing soft bit information for ECC correction without triggering a read error handling flow. Merging the soft bit and hard bit sense into one sequence can avoid extra overhead for read sequence operations.

Abstract: A non-volatile memory system separately performs a memory operation for multiple sub-blocks of a block in order from previously determined slowest sub-block of the block to a previously determined faster sub-block of the block. As a slower sub-block is more likely to fail, this order of is more likely to identify a failure earlier in the process thereby saving time and reducing potential for a disturb. In some embodiments, the proposed order of operation can be used in conjunction with a programming process that concurrently programs blocks in multiple planes using completion of programming of a fastest plane to a data state as a trigger to test for program failure of other planes to the data state.

Abstract: An apparatus is provided that includes a block including a word line coupled to a plurality of memory cells, and a control circuit coupled to the word line. The control circuit is configured to program the plurality of memory cells by applying program pulses to the word line in a plurality of program loops, determining a first count of a number of the program loops used to complete programming a first subset of the plurality of memory cells to a first programmed state, first comparing the first count to a corresponding first lower limit and a corresponding first upper limit, and determining whether programming the plurality of memory cells has failed based on a result of the first comparing step.

Abstract: Apparatuses and techniques are described for controlling a bit line pre-charge voltage in a program operation based on a number of bits per cell, with a goal to reduce peak current consumption. In one aspect, the ramp up of a bit line voltage to an inhibit level is optimized according to the number of bits per cell. The ramp up can involve increasing the bit line voltage from an initial level to a target voltage at a regulated rate, then increasing the bit line voltage from the target voltage to a final voltage at an unregulated rate. In one approach, the regulated ramp rate is less for single-level cell programming compared to multi-level cell programming. The target voltage can also be optimized based on the number of bis per cell.

Abstract: In a non-volatile memory system that performs programming of selected memory cells (in coordination with pre-charging and boosting of channels for unselected memory cells) and program-verify to determine whether the programming was successful, the system transitions from program-verify to the next dose of programming by concurrently lowering a voltage applied to a selected word line and voltages applied to word lines on a first side of the selected word line at the conclusion of program-verify. Subsequent to lowering the voltage applied to the selected word line, the system successively lowers voltages applied to groups of one or more word lines on a second side of the selected word line at the conclusion of program-verify beginning with a group of one or more word lines immediately adjacent the selected word line and progressing to other groups of one or more word lines disposed increasingly remote from the selected word line.

Abstract: An apparatus is provided that includes a block of memory cells and a control circuit coupled to the block of memory cells. The control circuit is configured to perform an erase operation on the block of memory cells by determining a first count of a number of times that the block of memory cells previously has been programmed and erased, determining a threshold number based on the first count, and determining whether the erase operation passed or failed based on the threshold number.

Abstract: The memory die that includes a plurality of memory blocks. Each memory block includes a plurality of memory cells that are configured to store three bits of data in each memory cell when the memory die is in a TLC operating mode. The memory die has a non-binary data capacity, which is a multiple of 683 Gb, when the memory die is operating in the TLC operating mode.

Abstract: To save power during a read process, NAND strings of each sub-block of a block have independently controlled source side select lines connected to source side select gates and drain side select lines connected to drain side select gates so that NAND strings of unselected sub-blocks can float and not draw current. To prevent read disturb in NAND strings of unselected sub-blocks, after all word lines are raised to a pass gate voltage, unselected word lines nearby the selected word line are lowered to respective intermediate voltages while lowering the voltage on the selected word line in order to achieve a channel potential gradient in the floated NAND strings of the unselected sub-blocks that does not result in read disturb. Subsequently, the selected word line is raised to the appropriate read compare voltage so the selected memory cells can be sensed.

Abstract: A memory apparatus and method of operation are provided. The memory apparatus includes memory cells connected to word lines and disposed in memory holes organized in rows grouped in strings. The memory cells are configured to retain a threshold voltage. The rows include full circle rows and semi-circle rows in which the memory holes are partially cut by a slit half etch. The memory holes of the semi-circle rows are coupled semi-circle bit lines and the memory holes of the full circle rows are coupled to full circle bit lines. A control means is configured to erase the memory cells in an erase operation. During the erase operation, the control means creates a capacitive coupling between each of the semi-circle bit lines and at least one neighboring one of the full circle bit lines to increase a semi-circle erase voltage applied to each of the semi-circle bit lines.

Abstract: To reduce spikes in the current used by a NAND memory die during a write operation using smart verify, different amounts of delay are introduced into the loops of the programing algorithm. Depending on the number of verify levels following a programming pulse, differing amounts of wait time are used before biasing a selected word line to the verify levels or levels. For example, if only a single verify level is used, a shorter delay is used than if two verify levels are used.

Abstract: To remedy short term data retention issues, a system creates a gate to channel voltage differential for non-volatile memory cells between programming and verifying in order to accelerate the effects of the short term data retention issue. That is, the gate to channel voltage differential will accelerate the migrating of electrons out of shallow traps. In some embodiments, the gate to channel voltage differential comprises a higher voltage at the channel in comparison to the gate. In some embodiments, the programming comprises applying doses of a programming signal and the gate to channel voltage differential is only created for a subset of the time periods between doses of the programming signal.

Abstract: In order to inhibit memory cells from programming and mitigate program disturb, the memory pre-charges channels of NAND strings connected to a common set of control lines by applying positive voltages to the control lines and applying voltages to a source line and bit lines connected to the NAND strings. The control lines include word lines and select lines. The word lines include an edge word line. The memory ramps down the positive voltages applied to the control lines, including ramping down control lines on a first side of the edge word line, ramping down the edge word line, and performing a staggered ramp down of three or more control lines on a second side of the edge word line. After the pre-charging, unselected NAND strings have their channel boosted to prevent programming and selected NAND strings experience programming on selected memory cells.

Abstract: A non-volatile storage apparatus that comprises a plurality of planes of non-volatile memory cells is capable of concurrently programming memory cells in multiple planes. In order to screen for failure of the programming process in a subset of planes, the completion of programming of a fastest plane to a particular data state is used as a trigger to test for program failure of other planes to a different data state. In one embodiment, the test for program failure of other planes to the different data state comprises determining if the memory cells of the other planes that are targeted for programming to the different data state have successfully completed verification of programming for the different data state. The programming process is stopped for those planes that fail the test.

Abstract: The memory device includes a memory block with an array of memory cells. The memory device also includes control circuitry that is in communication with the memory cells. The control circuitry is configured to program a group of the memory cells in a programming operation that does not include verify to obtain a natural threshold voltage (nVt) distribution, calculate an nVt width of the nVt distribution, compare the nVt width to a threshold, and identify the memory block as being vulnerable to cross-temperature read errors in response to the nVt width exceeding the threshold.

Abstract: The memory device includes a plurality of memory blocks that can individually operate in either a multi-bit per memory cell mode or a single-bit per memory cell mode. Certain voltage parameters during programming and reading are shared between these two operating modes, and certain voltage parameters are unique to each operating mode. One unique voltage parameter is a pass voltage VREADK that is applied to word lines adjacent a selected word line being read. Another unique voltage parameter is a VSGD voltage that is applied to a select gate drain transistor during programming. Yet another unique voltage parameter is an inhibit voltage that is applied to a bit line coupled with a memory cell being inhibited from programming while other memory cells are programmed.

Abstract: A method for multi-stage programming of a non-volatile memory structure, wherein the method comprises: (1) initiating a programming operation with respect to a memory block, (2) applying a programming algorithm to the memory block, wherein the programming algorithm comprises at least a first programming stage and a second programming stage, and (3) between the first programming stage and the second programming stage, applying a time delay according to a pre-determined amount of time. Further, the pre-determined amount of time may be defined as the amount of time that, according to a probabilistic function, permits de-trapping of any charges unintentionally trapped within a memory cell of the memory block as a result of the first programming stage.