Sandisk Technologies Inc.

Western Digital Technologies, Inc.

Guirong Liang

Dana Lee

Yanjie Wang

Dengtao Zhao

Zhenming Zhou

Gerrit Jan Hemink

Henry Chin

Haibo Li

Wenzhou Chen

Xiaoyu Che

Kroum Stanimirov Stoev

Anubhav Khandelwal

Shih-Chung Lee

Yongke Sun

Masaaki Higashitani

Deepanshu Dutta

Bo Lei

Changyuan Chen

Han-Ping Chen

Xiang Yang

Harish Reddy Singidi

Jianmin Huang

Jiahui Yuan

Jun Wan

Ting Luo

Ken Oowada

Gautam Ashok Dusija

Tai-Yuan Tseng

Deepak Raghu

Sarath Chandran Puthenthermadam

Yi Song

Ohwon Kwon

Kou Tei

Jianzhi Wu

Lanlan Gu

Anne Pao-Ling Koh

Shota Murai

Yonggang Wu

Chandu Gorla

Chris Aviala

Yasue Yamamoto

Shin-Chung Lee

A memory device includes a plurality of memory cells and control circuitry configured to perform a foggy-fine programming operation in which memory cells are programmed in multiple programming passes. To perform the foggy-fine programming operation, the control circuity is configured to perform a first pass of the foggy-fine programming operation on the memory cells, perform, in accordance with a first sense time, a first sensing operation on the memory cells programmed in the first pass of the foggy-fine programming operation, perform a second pass of the foggy-fine programming operation on the memory cells previously programmed in the first pass of the foggy-fine programming operation, and perform, in accordance with a second sense time, a second sensing operation on the memory cells programmed in the first pass and the second pass of the foggy-fine programming operation, wherein the second sense time is different from the first sense time.

Sense time separation in foggy-fine program to improve optimal VT width

The memory device includes a plurality of memory cells that are arranged in a plurality of word lines. A controller is provided, and the controller is configured to program the memory cells to respective threshold voltages in a programming operation. The controller is configured to, in the programming operation, apply a first voltage to a control gate of a selected word line of the plurality of word lines. The controller is also configured to continuously ramp a voltage applied to the control gate of the selected word line from the first voltage to a programming voltage over a first duration. The controller is further configured to hold the voltage applied to the control gate of the selected word line at the programming voltage over a second duration that is less than the first duration.

Programming techniques to reduce programming stress in a memory device

A method of operating a non-volatile semiconductor memory device is disclosed. The method comprises: during a first pre-read cycle of a read operation, ramping up a control signal on a wordline selected for the read operation to a first target pre-read voltage and ramping up a control signal on a drain-side select (SGD) transistor of an unselected string of the plurality of strings to a second target pre-read voltage. The method further comprises during a second pre-read cycle of the read operation, ramping down the control signal on the wordline to a target read voltage and ramping down the control signal on the SGD transistor of the unselected string to a third target pre-read voltage after a delay period after the triggering edge of the second pre-read cycle.

Pre-read cycle timing shrink by SGD bias control and page and wordline control

A storage device is disclosed herein. The storage device comprises: a non-volatile memory, where the non-volatile memory includes a block of N wordlines partitioned into a plurality of sub-blocks; and control circuitry coupled to the N wordlines. The control circuitry is configured to: determine a program status of an unselected sub-block of the plurality of sub-blocks before performing an operation on a selected sub-block of the plurality of sub-blocks; based on determining that the program status of the unselected sub-block is programmed, perform a precharge operation including applying a first precharge time; and based on determining that the program status of the unselected sub-block is not programmed, perform a precharge operation including applying a second precharge time, wherein the first precharge time is for a longer period than the second precharge time.

Sub-block status dependent device operation

A memory system having a dynamic supply voltage to sense amplifiers. The supply voltage has a higher magnitude when charging inhibited bit lines during a program operation and a lower magnitude when verifying/sensing memory cells. Reducing the magnitude of the supply voltage saves power and/or current. However, if the lower magnitude were used when the inhibited bit lines are charged during the program operations, some of the memory cells that should be inhibited from programming might experience at least some programming. Using the higher magnitude supply voltage during bit line charging of the program operation assures that the inhibited bit lines are charged to a sufficient voltage to keep drain side select gates of NAND strings off so that the NAND channel will boost properly to inhibit programming of such memory cells.

Dynamic sense amplifier supply voltage for power and die size reduction

A memory apparatus and method of operation is provided. The apparatus includes memory cells each connected to one of a plurality of word lines. The memory cells are disposed in strings coupled to one of a plurality of bit lines and are configured to retain a threshold voltage corresponding to one of a plurality of data states. A control means is configured to read each of the memory cells in a read operation. For each one of the memory cells, the control means is also configured to offset at least one of a bit line settling time and a kick voltage during the read operation based on a probability of at least one neighboring one of the plurality of bit lines being coupled to the memory cells retaining the threshold voltage corresponding to a different one of the plurality of data states than the one of the memory cells.

Utilizing data pattern effect to control read clock timing and bit line kick for read time reduction

To help reduce program disturbs in non-selected NAND strings of a non-volatile memory, a sub-block based boosting scheme in introduced. For a three dimensional NAND memory structure, in which the memory cells above a joint region form an upper sub-block and memory cells below the joint region form a lower sub-block, dummy word lines in the joint region act as select gates to allow boosting at the sub-block level when the lower block is being programmed in a reverse order.

Non-volatile memory with sub-block based self-boosting scheme

An apparatus includes a plurality of solid-state storage elements, a plurality of control lines coupled to the plurality of solid-state storage elements, and control circuitry in communication with the plurality of control lines. The control circuitry is configured to during a first phase of a control line pre-charging stage, charge one or more unselected control lines of the plurality of control lines using a regulated charging current for a period of time based at least in part on a predicted parasitic capacitance associated with the programming state of the control lines, and during a second phase of the control line pre-charging stage, charge the one or more unselected bit lines to an inhibit voltage level using an unregulated charging current.

Peak current and program time optimization through loop dependent voltage ramp target and timing control

The non-volatile memory includes a control circuitry that is communicatively coupled to an array of memory cells that are arranged in a plurality of word lines. The control circuitry is configured to program the memory cells of the plurality of word lines to a plurality of data states in a multi-pass programming operation. A later programming pass of the multi-pass programming operation includes a plurality of programming loops with incrementally increasing programming pulses. For at least one data state, the later programming pass includes maintaining a count of the programming loops of the later programming pass. The later programming pass also includes inhibiting or slowing programming of the memory cells being programmed to one of the data states during a predetermined program count verify (PCV) programming loop and a PCV&#x2212;1 programming loop and skipping a verify operation for all programming loops prior to a PCV+1 programming loop.

Memory programming with selectively skipped verify pulses for performance improvement

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 determine data states for a first set of memory cells of a neighboring word line of the set of word lines, determine a bit line voltage bias and a sense time for a memory cell of a second set of memory cells of the selected word line based on a data state determined for a memory cell for each memory cell of the second set of memory cells, and perform a verify operation on the selected word line using the bit line voltage bias and the sense time determined for each memory cell of the second set of memory cells.

Neighbor word line compensation full sequence program scheme

Apparatuses, systems, methods, and computer program products are disclosed for state-dependent read compensation. A set of non-volatile storage cells comprising a plurality of word lines. A controller is configured to perform a read operation on one or more word lines adjacent to a target word line. A controller is configured to determine a read setting for application to a target word line based on a result of a read operation on one or more word lines adjacent to the target word line. A controller is configured to perform a read operation on a target word line using a determined read setting.

State-dependent read compensation

Systems and methods for sampling data at a non-volatile memory system are disclosed. In one implementation, a controller of a non-volatile memory system that is coupled with a host device acquires a read level voltage of a first word line of a memory block of a non-volatile memory of the non-volatile memory system. The controller accesses one or more lookup tables to determine an offset voltage for a second word line of the memory block based on a program/erase count and a read/disturb count associated with the memory block; applies the read level voltage and the offset voltage to the second word line to sample data stored at the memory block; and determines whether the data sampled from the memory block contains errors.

Systems and methods for sampling data at a non-volatile memory system

Systems and methods are disclosed for programming data in a non-volatile memory array are disclosed. A data storage device includes a non-volatile memory array including a plurality of non-volatile memory cells and a controller configured to receive a signal indicating a temperature of at least a portion of the data storage device. The controller determines a first offset program verify level associated with a first programming level based at least in part on the temperature and programs a first set of the memory cells of the non-volatile memory array using the first offset program verify level.

Temperature compensation management in solid-state memory

A method includes, responsive to a power-up event at a data storage device that includes a memory, reading a flag stored at the data storage device and determining that the flag has a first value indicating that a reflow operation has not previously been detected at the memory. The method also includes, in response to determining that the flag has the first value, performing reflow detection at the memory. The method further includes, in response to the reflow detection indicating that the reflow operation has occurred, setting the flag to a second value.

Data storage device having reflow awareness

Systems and methods for performing partial block erase operations on a subset of word lines within a memory array prior to performing data refreshing or open-block programming are described. In some cases, data stored in memory cells connected to a word line with a fail bit count above an error threshold (e.g., more than two bit errors per page or more than three bit errors per word line) may be refreshed by performing a read operation on the memory cells, generating corrected data for the memory cells, performing a partial block erase operation on one or more word lines including the word line, and then writing the corrected data into the memory cells. The one or more word lines may include the word line with the fail bit count above the error threshold and an adjacent word line that is adjacent to the word line.

Growing community of inventors

Santa Clara, CA, United States of America

Guirong Liang