Abstract: Memory cells are arranged as NAND strings to form a block divided into sub-blocks, and each NAND string includes a dummy memory cell connected to a dummy word line. Memory cells are programmed by applying programming pulses to a selected word line in a selected sub-block with program-verify performed between pulses. Unselected NAND strings are inhibited from programming by boosting channels of the unselected NAND strings in the selected sub-block from a positive pre-charge voltage to a boosted voltage. The pre-charging of the channels of unselected NAND strings is performed while lowering voltages at the end of program-verify by applying overdrive voltages to data word lines in a sub-block closer to the source line than the selected sub-block and lowering to a resting voltage a dummy word line between the sub-blocks prior to lowering to a resting voltage the data word lines in the sub-block closer to the source line.

Abstract: A non-volatile memory device includes a control circuit configured to connect to a bit line that is connected to one or more non-volatile memory cells. The control circuit includes a first plurality of data latches connected to a first local data bus to store first program-verify pass/fail bits and a second plurality of data latches connected to a second local data bus to store second program-verify pass/fail bits for second non-volatile memory cells. The non-volatile memory device further includes a shared isolation latch and one or more interface circuits connected to the first local data bus and the second local data bus. The one or more interface circuits are configured to selectively block the first program-verify pass/fail bits from the first plurality of latches and the second program-verify pass/fail bits from the second plurality of latches according to an indicator bit stored in the shared isolation latch.

Abstract: For a non-volatile memory that uses hard bit and soft bit data in error correction operations, to reduce the amount of soft bit data that needs to be transferred from a memory to the controller and improve memory system performance, the soft bit data can be compressed before transfer. After the soft bit data is read and stored into the internal data latches associated with the sense amplifiers, it is compressed within these internal data latches. The compressed soft bit data can then be transferred to the transfer data latches of a cache buffer, where the compressed soft bit data can be consolidated and transferred out over an input-output interface. Within the input-output interface, the compressed data can be reshuffled to put into logical user data order if needed.

Abstract: Technology is disclosed herein reconfiguring word lines as either data word lines or dummy word lines. In a sub-block mode reconfigurable word lines are used as dummy word lines that provide electrical isolation between data word lines in a block. The block may be divided into an upper tier, a middle tier, and a lower tier, with the reconfigurable word lines within the middle tier. In a full-block mode the reconfigurable group of the word lines are used as data word lines. Because the reconfigurable word lines are used as data word lines in the full-block mode storage capacity is greater in the full-block mode than in the sub-block mode. Moreover, because the sub-blocks are smaller in size but greater in number than the full-blocks, the memory system may be provisioned with fewer blocks and still meet user storage requirements in both the full-block mode and the sub-block mode.

Abstract: Non-volatile memory cells are programmed by pre-charging channels of unselected non-volatile memory cells connected to a selected data word line, boosting the channels of unselected non-volatile memory cells connected to the selected data word line after the pre-charging and applying a program voltage pulse to selected non-volatile memory cells connected to the selected data word line while boosting. The pre-charging includes applying pre-charge voltages to one set of data word lines and dummy word line(s) as well as applying overdrive voltages to another set of data word lines connected to already programmed memory cells. At the end of the pre-charging, the dummy word lines are ramped down to a resting voltage prior to lowering the data word lines to one or more resting voltages.

Abstract: A local data bus of a sense amplifier associated with one bit line is used to perform logical operations for a sensing operation performed by another sense amplifier associated with a different bit line. Each sense amplifier circuit includes a sensing node that is pre-charged, then discharged through a selected memory cell and a local data bus with a number of data latches connected. Target program data can be stored in the latches and combined in logical combinations with the sensed value of the memory cell to determine whether it has verified. By including a transfer circuit between the local data buses of a pair of sense amplifiers, the logical operations of a first sense amplifier can be performed using the local data bus of the paired sense amplifier, freeing the first sense amplifier's sense node to be concurrently pre-charged for a subsequent sensing operation, thereby improving performance.

Abstract: Technology for applying a positive temperature coefficient (Tco) voltage to a control terminal of a dummy select transistor. The dummy select transistor resides on a NAND string having non-volatile memory cells and a regular select transistor. The dummy select transistor is typically ON (or conductive) during memory operations such as selected string program, read, and verify. In an aspect, the positive Tco voltage is applied to the control terminal of a dummy select transistor during a program operation. Applying the positive Tco voltage during program operations reduces or eliminates program disturb to the dummy select transistor. In some aspects, the dummy select transistor is used to generate a gate induced drain leakage (GIDL) current during an erase operation. In some aspects, the dummy select transistor is a depletion mode transistor.

Abstract: For a non-volatile memory that uses hard bit and soft bit data in error correction operations, to reduce the amount of soft bit data that needs to be transferred from a memory to the controller and improve memory system performance, the soft bit data can be compressed before transfer. After the soft bit data is read and stored into the internal data latches associated with the sense amplifiers, it is compressed within these internal data latches. The compressed soft bit data can then be transferred to the transfer data latches of a cache buffer, where the compressed soft bit data can be consolidated and transferred out over an input-output interface. Within the input-output interface, the compressed data can be reshuffled to put into logical user data order if needed.

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 non-volatile memory, to achieve a shallow and tight erased threshold voltage distribution, a process is performed that includes erasing a group of non-volatile memory cells, identifying a first set of the bit lines that are connected to non-volatile memory cells of the group that are erased past a lower limit for erased non-volatile memory cells and identifying a second set of the bit lines that are connected to non-volatile memory cells of the group that are not erased past the lower limit for erased non-volatile memory cells, and applying programming to non-volatile memory cells connected to the first set of bit lines while inhibiting programming for non-volatile memory cells connected to the second set of bit lines.

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 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 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: 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: 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: 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: 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: 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: 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.