Sandisk Technologies Inc.

Sandisk Corporation

Western Digital Technologies, Inc.

Sandick Technologies Inc.

Henry Chin

Nima Mokhlesi

Dana Lee

Dengtao Zhao

Wei Zhao

Vinod Robert Purayath

Deepanshu Dutta

James K Kai

George Matamis

Henry Chien

Takashi Whitney Orimoto

Han-Ping Chen

Erika Penzo

Gerrit Jan Hemink

Yingda Dong

Anubhav Khandelwal

Cynthia Hsu

Guirong Liang

Yuan Zhang

Lei Lin

Zhenming Zhou

James Fitzpatrick

Abhijeet Manohar

Richard David Barndt

Daniel Edward Tuers

Niranjay Ravindran

Hong-Yan Chen

Deepak Raghu

Hua-Ling Cynthia Hsu

Ravi J Kumar

Pitamber Shukla

Fanglin Zhang

Mostafa El Gamal

Tapan Samaddar

Bernie Rub

Zhuojie Li

Masaaki Higashitani

Johann Alsmeier

Xiang Yang

Jeffrey W Lutze

Tuan Duc Pham

Liang Li

Ching-Huang Lu

George Samachisa

Hiroyuki Kinoshita

Chris Avila

Shih-Chung Lee

Ashish Kumar Baraskar

Zhengyi Zhang

Donovan Lee

Xuan Tian

Atsushi Suyama

Ming Tian

Dong-Il Moon

Jian Feng Chen

Peter Rabkin

Jiahui Yuan

Huai-Yuan Tseng

Yu-Chung Lien

Ken Oowada

Gautam Ashok Dusija

Changyuan Chen

Bo Lei

Tai-Yuan Tseng

Abhijith Prakash

Sarath Chandran Puthenthermadam

Muhammad Masuduzzaman

Vinh Diep

Pao-Ling Koh

Yanjie Wang

Qing Li

Xiaoyu Yang

Abu Naser Zainuddin

Joanna Lai

Yichao Huang

Abhilash Ravi Kashyap

Sateesh Desireddi

Arash Hazeghi

Parth Amin

Jianzhi Wu

Toru Ishigaki

Jia Li

Shota Murai

Vincent Yin

Zelei Guo

Guanhua Yin

Jie Liu

LanLan Gu

Dong-II Moon

Tony Zou

Ching Huang Lu

Ashwin D T

Harshul Gupta

Technology is disclosed herein for smart verify in a memory system that has a four bit per cell program mode (or X4 mode) and also a three bit per cell program mode (or X3 mode). The X3 mode uses a three-bit gray code that is based on a four-bit gray code of the X4 mode. The memory system skips verify of states in the X3 mode, while using a considerable portion of the programming logic from the X4 mode. In one X3 mode the memory system skips B-state verify while the number of memory cells having a Vt above an A-state verify voltage is below a threshold. In one X3 mode the memory system determines whether to skip verify for a first set of data states based on a first test and determines whether to skip verify for a second set of data states based on a second test.

Hybrid smart verify for QLC/TLC die

A memory device that includes a plurality of memory cells arranged in an array is provided. A control circuitry is configured to program a single bit of data in each memory cell of the plurality of memory cells. The control circuitry is further configured to program a first set of memory cells of the plurality of memory cells using a first programming operation that includes a single programming pulse and no verify pulse and program a second set of memory cells of the plurality of memory cells using a second programming operation that includes at least one programming loop with a programming pulse and a verify pulse.

Memory programming techniques to reduce power consumption

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.

Memory device with unique read and/or programming parameters

A storage device including control circuitry, communicatively coupled to a non-volatile memory, configured to perform a programming operation to program a set of memory cells. The control circuitry, when performing the programming operation, may be configured to apply a set of biased program voltages to lines connecting to respective memory cells in an array. The set of biased program voltages may have values that are based on positions of the respective memory cells within the array relative to an outer memory string group of a set of memory string groups.

Programming of memory cells using a memory string dependent program voltage

A memory apparatus and method of operation are provided. The apparatus includes memory cells connected word lines. The memory cells are disposed in strings and configured to retain a threshold voltage. A control means is configured to apply a program voltage to selected ones of the word lines while applying pass voltages to unselected ones of the word lines and ramp down both the selected ones of the plurality of word lines and the unselected ones of the word lines to a recovery voltage at a start of a verify phase of each of a plurality of program loops and apply a targeted word line bias to each of the word lines during the verify phase. The control means is also configured to adjust the recovery voltage based on the targeted word line bias applied to each of the plurality of word lines during the verify phase.

Read pass voltage dependent recovery voltage setting between program and program verify

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.

Techniques for checking vulnerability to cross-temperature read errors in a memory device

The memory device includes a plurality of dies, and each die includes a plurality of blocks with a plurality of word lines. Some of the word lines are arranged in a plurality of exclusive OR (XOR) sets with each XOR set containing word lines in the same positions across the plurality of dies. The memory device further includes a controller that is configured to program the word lines of the blocks of at least one of the dies in a first programming direction. The controller is further configured to program the word lines of the blocks of at least one other die in a second programming direction that is opposite of the first programming direction.

Mixing normal and reverse order programming in NAND memory devices

A memory apparatus and method of operation are provided. The apparatus includes memory cells each connected to one of a plurality of word lines. The memory cells are disposed in strings and configured to retain a threshold voltage corresponding to one of a plurality of data states. A control means is coupled to the plurality of word lines and the strings and is configured to apply a read voltage to a selected ones of the plurality of word lines during a read operation and ramp down to a discharge voltage at an end of the read operation and apply a ready voltage to the selected ones of the plurality of word lines during a ready period of time following the read operation. The control means is also configured to adjust at least one of the discharge voltage and the ready voltage based on a temperature of the memory apparatus.

Temperature-dependent word line voltage and discharge rate for refresh read of non-volatile memory

An apparatus disclosed herein comprises: a plurality of memory cells and a control circuit coupled to the plurality of memory cells. The control circuit is configured to: acquire a first set of read levels on a wordline of a first block of pages of memory cells; acquire a second set of read levels on a first wordline of a second block of pages of a second set of memory cells in response to determining that the fail bit count of the page after a read operation is above the threshold amount; and acquire a third set of read levels on a second wordline of the second block in response to determining that the fail bit count of the page after the second read operation is above the threshold amount.

Time-tagging read levels of multiple wordlines for open block data retention

An apparatus is provided that includes a plurality of word lines that include a plurality of word line zones, a plurality of non-volatile memory cells coupled to the plurality of word lines, and a control circuit coupled to the non-volatile memory cells. The control circuit is configured to determine a corresponding initial program voltage for each of the word line zones. Each corresponding initial program voltage is determined based on a number of program erase cycles.

Word line zoned adaptive initial program voltage for non-volatile memory

Techniques disclosed herein cope with temperature effects in non-volatile memory systems. A control circuit is configured to sense a current temperature of the memory system and read, verify, program, and erase data in non-volatile memory cells by modifying one or more read/verify/program/erase parameters based on a temperature compensation value. The control circuit is further configured to read, verify, program, and erase data by accessing a historical temperature value stored in the memory system, the historical temperature value comprising a temperature at which a previous read, verify, program or erase occurred and measuring a current temperature value. The control circuit determines the temperature compensation value by applying a smoothing function. The smoothing function determines the temperature compensation value by selecting either the historical temperature value or the current temperature value as the temperature compensation value based on a difference between the historical temperature value and the current temperature relative to a threshold, or calculating the temperature compensation value, different from the current temperature value or the historical temperature value, based a smoothing function which utilizes the current temperature value and the historical temperature value.

Digital temperature compensation filtering

Technology is provided for extending the useful life of a block of memory cells by changing an operating parameter in a physical region of the block that is more susceptible to wear than other regions. Changing the operating parameter in the physical region extends the life of that region, which extends the life of the block. The operating parameter may be, for example, a program voltage step size or a storage capacity of the memory cells. For example, using a smaller program voltage step size in a sub-block that is more susceptible to wear extends the life of that sub-block, which extends the life of the block. For example, programming memory cells to fewer bits per cell in the region of the block (e.g., sub-block, word line) that is more susceptible to wear extends the useful life of that region, which extends the life of the block.

Reliability compensation for uneven NAND block degradation

Storage device programming methods, systems and devices are described. A method may generate a mapping of data based on a set of data, the mapping of data including a first mapped data and a second mapped data. The method may include performing a first programming operation to write, in a first mode, the first mapped data to the memory device. The method may include storing the second mapped data to a cache. The method may include generating a second set of data, based on an inverse mapping of the mapping of data including the second mapped data from the cache and the first mapped data from the memory device, for writing, in a second mode, to the memory device, wherein the second set of data includes the set of data, and the first mode and the second mode correspond to different modes of writing to the memory device.

Mapping for multi-state programming of memory devices

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

Countermeasure method for programming a non-defective plane of a non-volatile memory experiencing a neighbor plane disturb, comprising, once a first plane is determined to have completed programming of a current state but where not all planes have completed the programming, a loop count is incremented and a determination is made as to whether the loop count exceeds a threshold. If so, programming of the incomplete plane(s) is ceased and programming of the completed plane(s) is resumed by suspending the loop count and bit scan mode, and, on a next program pulse, applying a pre-determined rollback voltage to decrement a program voltage bias. The loop count and bit scan mode are resumed once a threshold voltage level equals a program voltage bias when the loop count was last incremented. BSPF criterion is applied for each programmed state. Advancement to the next loop only occurs if a programmed state is determined incomplete.

Countermeasure modes to address neighbor plane disturb condition in non-volatile memory structures

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Fremont, CA, United States of America

Henry Chin