Sandisk Technologies Inc.

Xue Bai Pitner

Ravi J Kumar

Yu-Chung Lien

Deepanshu Dutta

Sujjatul Islam

Huai-Yuan Tseng

Raghuveer S Makala

Jiahui Yuan

Fei Zhou

Senaka Kanakamedala

Ken Oowada

Dengtao Zhao

Bo Lei

Sarath Chandran Puthenthermadam

Cynthia Hsu

Muhammad Masuduzzaman

Ramy Nashed Bassely Said

Zhenni Wan

Prafful Golani

A method for performing a program verify operation with respect to a target memory cell in a memory structure of a non-volatile memory system is provided. The method may include the step of determining a location of the target memory cell within the structure and, based upon the determined location of the target cell and with respect to each programmable memory state: (1) applying a first sense signal at a first point in time, and (2) applying a second sense signal at a second point in time. A time interval between the first and the second points in time is equal to a predetermined optimal time period plus or minus an offset parameter time value.

Location dependent sense time offset parameter for improvement to the threshold voltage distribution margin in non-volatile memory structures

A non-volatile semiconductor memory device, described herein, comprises non-volatile storage elements and one or more control circuits in communication with the non-volatile storage elements. The one or more control circuits are configured to, during a program iteration of a program operation, determine whether a program voltage level of the program iteration exceeds a threshold program voltage level and in response to the determination, identify a set of voltage levels to apply to a source line connected to a set of the non-volatile storage elements. The one or more control circuits are further configured to perform the program iteration of the program operation on the set of non-volatile storage elements, where the program iteration includes applying the set of voltage levels to the source line.

Program voltage dependent program source levels

A non-volatile semiconductor memory device includes non-volatile storage elements and one or more control circuits in communication with the non-volatile storage elements. The one or more control circuits are configured to determine for a program iteration of a program operation on a word line whether a condition is met and in response to determining that the condition is met, identify one or more memory cells of the word line that are in an erased state that have a threshold voltage higher than an erase threshold voltage and perform the program iteration of the program operation. The program iteration includes applying a first bitline inhibit voltage to bitlines connected to the identified one or more memory cells and a second bitline inhibit voltage to bitlines connected to one or more memory cells that are in the erased state that do not have a threshold voltage higher than the erase threshold voltage.

Selective inhibit bitline voltage to cells with worse program disturb

The memory device includes a plurality of memory cells, which include a first set of memory cells and a second set of memory cells. A controller is in communication with the memory cells. The controller is configured to, in a first programming pass and then a second programming pass, program the memory cells of the first and second sets to respective final threshold voltages associated with a plurality of programmed data states. The controller is further configured to, in the first programming pass, verify the first set of memory cells at a first set of checkpoint data states and verify the second set of memory cells at a second set of checkpoint data states that is different than the first set of checkpoint data states.

Verify techniques for current reduction in a memory device

A method for programming a target memory cell of a memory array of a non-volatile memory system, the method comprises determining a total number of erase/programming (EP) cycles that were applied previously to the memory cell and, (1) if the determined total number of cycles does not exceed a threshold value, applying an asymmetric programming scheme, and, (2) if the determined total number of cycles exceeds the threshold value, applying a symmetric programming scheme. Further, a magnitude of a boosting voltage bias (VPASS) that is to be applied to an unselected word line may be determined according to the determined total number of erase/programming (EP) cycles.

EP cycling dependent asymmetric/symmetric VPASS conversion in non-volatile memory structures

A memory device includes an alternating stack of insulating layers and electrically conductive layers, a memory opening vertically extending through the alternating stack, and memory opening fill structures located in the memory opening and including a vertical semiconductor channel, a dielectric material liner laterally surrounding the vertical semiconductor channel, and a vertical stack of discrete memory elements laterally surrounding the dielectric material liner. A subset of the insulating layers a lower insulating sublayer, an upper insulating sublayer overlying the lower insulating sublayer, and a center insulating sublayer located between and in contact with the lower insulating sublayer and the upper insulating sublayer.

Three-dimensional memory device including discrete charge storage elements and methods for forming the same

A method for programming a memory block of a non-volatile memory structure, wherein the method provides, during a program verify operation, selecting only a partial segment of memory cells of a memory block for bit scan mode, applying a sensing bias voltage to one or more bit lines of the memory block associated with the selected memory cells, and initiating a bit scan mode of the selected memory cells.

Peak and average ICC reduction by tier-based sensing during program verify operations of non-volatile memory structures

A memory apparatus and method of operation is provided. The apparatus includes a block of memory cells. Each of the memory cells is connected to one of a plurality of word lines and are also arranged in strings and configured to retain a threshold voltage within a common range of threshold voltages. A control circuit coupled to the plurality of word lines and the strings is configured to determine an erase upper tail voltage of a distribution of the threshold voltage of the memory cells following an erase operation. The erase upper tail voltage corresponds to a cycling condition of the memory cells. The control circuit is also configured to calculate a program voltage to apply to each of selected ones of the plurality of word lines associated with the memory cells to program the memory cells during a program operation based on the erase upper tail voltage.

Memory apparatus and method of operation using zero pulse smart verify

The non-volatile memory includes a control circuitry that is communicatively coupled to an array of memory cells that are arranged word lines. The control circuitry is configured to program the memory cells using a multi-pass programming operation which includes a first pass and a second pass. The first pass programs the memory cells to a first number of data states, and the second pass programs the memory cells to a greater second number of data states. For at least one word line, during the second pass, a voltage that is applied to at least one memory cell is reduced from a verify voltage by an offset which is determined as a function of a data state of an adjacent memory cell of an adjacent word line and wherein the first pass but not the second pass has been completed in the adjacent word line.

Modified verify in a memory device

Apparatuses and techniques are described for reducing the program time for a set of memory cells by using an enhanced step up of a program bias. A program operation includes a first pass in which memory cells are programmed to intermediate states and a second program pass in which the memory cells are programmed from an erased state and the intermediate states to final states. In the first program pass, program time can be reduced by applying an enhanced program bias step up to memory cells of the highest intermediate state in a single program loop, for example. The enhanced program bias step up can be achieved by applying a negative bit line voltage and can be triggered when the memory cells assigned to the second highest intermediate state reach a program milestone such as completing programming.

Reduced program time for memory cells using negative bit line voltage for enhanced step up of program bias

A memory apparatus and method of operation is provided. The apparatus includes a block of memory cells each connected to one of a plurality of word lines and arranged in strings and configured to retain a threshold voltage. A control circuit couples to the word lines and the strings determines a program lower tail voltage of a distribution of the threshold voltage following a first program pulse. The control circuit calculates a second program voltage of a second program pulse based on the program lower tail voltage and applies the second program pulse to each of selected ones of the plurality of word lines associated with the memory cells to program the memory cells such that the distribution of the threshold voltage of the memory cells have a desired program lower tail voltage without further program pulses.

Memory apparatus and method of operation using one pulse smart verify

A storage device is disclosed herein. The storage device comprises a block including a plurality of memory cells and a circuit coupled to the plurality of memory cells of the block. The circuit is configured to program memory cells of a plurality of strings of a word line of the block and verify, for a plurality of sets of the memory cells, a data state of a set of the memory cells, where each set of the plurality of sets of the memory cells includes a memory cell from each string of the plurality of strings of the word line. Further, the circuit is configured to determine a number of sets of the plurality of memory cell sets that are verified to be in a first data state and determine, based on the number of sets, whether the block is faulty.

Programming techniques including an all string verify mode for single-level cells of a memory device

A storage device including control circuitry, communicatively coupled to a non-volatile memory, configured to receive a parity bit that has been stored using a data structure, and to receive a first subset of host data that includes block data relating to a set of memory cells. The control circuitry may be configured to perform a read operation to identify a second subset of host data that includes additional block data relating to the set of memory cells. The control circuitry may be configured to decode the second subset of host data using the parity bit. The control circuitry may be configured to perform a write operation to write the block data to at least one or more memory cells that are part of the set of memory cells.

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Sunnyvale, CA, United States of America

Xue Bai Pitner