Patents Assigned to SanDisk Technologies Inc.
  • Patent number: 9389673
    Abstract: A method includes entering a hibernation mode in a data storage device with a controller, a non-volatile memory, and a volatile memory having a first portion and a second portion. The hibernation mode is entered by copying, to the second portion, data that is in the first portion and that is flagged to remain available at the volatile memory during the hibernation mode, and powering off the first portion while maintaining power to the second portion.
    Type: Grant
    Filed: December 22, 2011
    Date of Patent: July 12, 2016
    Assignee: SANDISK TECHNOLOGIES INC.
    Inventors: Daniel Zvi Yerushalmi, Yaniv Iarovici
  • Patent number: 9384126
    Abstract: The various implementations described herein include systems, methods and/or devices used to avoid false negative results in Bloom filters implemented in non-volatile data storage systems. In one aspect, if an element is added to a Bloom filter using k hash functions, instead of requiring all k bits to be set before returning a positive result (e.g., indicating that the element is most likely present in the Bloom filter), the embodiments described herein return a positive result when at least k minus x (k?x) bit positions are set in the Bloom filter, where x is an integer greater than zero and less than k. In some embodiments, additional measures to avoid false negatives include performing a read check immediately after setting the k bits in the Bloom filter and/or using a conservative reading threshold voltage.
    Type: Grant
    Filed: September 24, 2013
    Date of Patent: July 5, 2016
    Assignee: SANDISK TECHNOLOGIES INC.
    Inventors: Steven Sprouse, Yan Li
  • Patent number: 9384128
    Abstract: In the controller circuit of a non-volatile memory system, data is protected by CRC (cyclic redundancy code) between functional blocks of the controller: Before a data set is transmitted from one functional block (such the host interface) to another functional block (such as data encryption or ECC), corresponding CRC is generated and transferred with the data. At the second block, the data set can be checked with the CRC at the second block before it operates on the data. This allows the controller to check for internal transfer errors early, allow for corrupted data to be re-requested, such as from a host when this process is applied to a data write operation. After the second block finishes with the data, a new CRC can then be generated to protect the data on its next internal transfer. This arrangement can particularly useful for functional blocks that transform the data set.
    Type: Grant
    Filed: April 18, 2014
    Date of Patent: July 5, 2016
    Assignee: SanDisk Technologies, Inc.
    Inventors: Daniel Tuers, Abhijeet Manohar
  • Publication number: 20160188401
    Abstract: Systems and methods for controlling blocks in a memory device using a health indicator (such as the failed bit count) for the blocks are disclosed. However, the health indicator may exhibit noise, thereby resulting in an unreliable indicator of the health of the blocks in the memory device. In order to filter out the noise, a rolling average of the health indicator may be determined, and compared to the current health indicator. The comparison with the rolling average may indicate whether the current health indicator is an outlier, and thus should not be used. The health indicator may also be used to predict a future health indicator for different blocks in the memory device. Using the predicted future health indicator, the use of the blocks may be changed in order to more evenly wear the blocks.
    Type: Application
    Filed: December 29, 2014
    Publication date: June 30, 2016
    Applicant: SanDisk Technologies Inc.
    Inventors: Zhenlei Shen, Xinde Hu, Lei Chen, Yiwei Song
  • Publication number: 20160189778
    Abstract: In a non-volatile memory formed according to a NAND-type architecture that has, on one or both ends of the NAND strings, multiple select gates including some with programmable threshold voltages, a structure and corresponding for efficiently programming of such select gates. On the drain side, the end most of multiple drain select transistors is individually controllable and used for biasing purposes while one or more other drain side select gates are collectively programmed to set adjust their threshold voltage. Independently, on the source side, the end most of multiple source select transistors is individually controllable and used for biasing purposes while other source side select gates are collectively programmed to set adjust their threshold voltage.
    Type: Application
    Filed: March 7, 2016
    Publication date: June 30, 2016
    Applicant: SanDisk Technologies, Inc.
    Inventors: Hao NGUYEN, Man MUI, Khanh NGUYEN, Seungpil LEE, Toru ISHIGAKI, Yingda DONG
  • Publication number: 20160189758
    Abstract: Methods and apparatuses for performing receive and transmit path tuning of a toggle mode interface between a primary controller and a secondary controller is disclosed. A first component having a variable setting and connected with a data bus of the interface is iteratively adjusted. For each setting of the first component, test data written to the secondary controller and a delay unit having a variable delay setting and connected with a strobe line of the interface is adjusted. Delay settings are identified where the read data is equal to the written data. Settings for the first component and corresponding delay setting that produce the largest range of delay settings where the read data is equal to the written data is selected. The first component may correspond to a driver unit in the primary controller or an ODT unit in the secondary controller.
    Type: Application
    Filed: June 15, 2015
    Publication date: June 30, 2016
    Applicant: SanDisk Technologies Inc.
    Inventors: Sateesh Desireddi, Srinivasa Rao Sabbineni, Shiv Harit Mathur
  • Publication number: 20160188502
    Abstract: Ring bus architectures for use in a memory module are disclosed. A memory module may include a ring bus controller and a bus bridge positioned on a primary ring bus. The memory module also includes a secondary ring bus in communication with the bus bridge and a plurality of non-volatile memory units. The ring bus controller is configured to send a configuration command to the bus bridge via the primary bus ring, where the configuration command includes an indication to route future commands and/or data to the secondary ring bus extending from the bus bridge. The bus bridge is configuration to, in response to the configuration command, configure the bus bridge to route future commands and/or data from the primary ring bus to the secondary ring bus.
    Type: Application
    Filed: December 29, 2014
    Publication date: June 30, 2016
    Applicant: SanDisk Technologies Inc.
    Inventor: Alan Welsh Sinclair
  • Publication number: 20160188404
    Abstract: A memory system or flash card may optimize usage of reclaimed memory. The optimization may include lists for Uncorrectable Error Correction Code (UECC) and Correctable Error Correction Code (CECC) that can be used along with a dual programming scheme. Dual programming may be utilized for blocks on the lists, but not for blocks that are not on the lists. The lists can be updated by reading data programmed to blocks on the lists.
    Type: Application
    Filed: March 19, 2015
    Publication date: June 30, 2016
    Applicant: SanDisk Technologies Inc.
    Inventor: Srikanta Das
  • Publication number: 20160188464
    Abstract: A method and system for using non-volatile memory as a replacement for volatile memory are provided. In one embodiment, a host is in communication with a memory system having volatile memory, a first non-volatile memory, and a second non-volatile memory, wherein the first non-volatile memory has a faster performance and a higher endurance than the second non-volatile memory. The host analyzes data to be stored in the volatile memory to determine if it should instead be stored in the first non-volatile memory. If the data should be stored in the volatile memory, the host stores the data in the volatile memory. If the data should be stored in the first non-volatile memory, the host stores the data in the first non-volatile memory.
    Type: Application
    Filed: December 30, 2014
    Publication date: June 30, 2016
    Applicant: SanDisk Technologies Inc.
    Inventors: Shahar Bar-Or, Vsevolod Mountaniol
  • Publication number: 20160188206
    Abstract: Non-volatile memory systems utilizing storage address tables are disclosed. A non-volatile memory system may include a non-volatile memory, a memory die command manager in communication with the memory, and a command manager in communication with the memory die command manager. The memory die command manager is configured to identify a free die of the memory to store data, where the free die of the memory is identified independent of a host logical block address associated with the data; store the data at a physical block address at the free die; and generate an entry in a first address table, the first address table associating the physical block address with a virtual logical block address. The command manager is configured to generate an entry in a second address table, the second address table associating the virtual logical block address with a host logical block address received with the host write command.
    Type: Application
    Filed: December 29, 2014
    Publication date: June 30, 2016
    Applicant: SanDisk Technologies Inc.
    Inventor: Alan Welsh Sinclair
  • Publication number: 20160189786
    Abstract: A method for operating non-volatile memory device is provided. The method includes applying a first voltage level to a word line connected to a memory cell, applying a second voltage level to the word line for a first time period, performing a read operation on the memory cell during the first time period, and discharging the word line for a second time period to a third voltage level greater than or equal to about 1V. The method also includes performing an erase word line recovery on a plurality of blocks of memory cells during the erase operation, and prior to an erase phase. The erase word line recovery substantially discharges all word lines of the plurality of blocks of memory cells.
    Type: Application
    Filed: October 29, 2015
    Publication date: June 30, 2016
    Applicant: SANDISK TECHNOLOGIES INC.
    Inventors: Manabu Sakai, Tayuka Ariki
  • Publication number: 20160188455
    Abstract: Systems and methods for choosing a memory block for the storage of data based on a frequency with which data is updated are disclosed. In one implementation, a memory management module of a non-volatile memory system receives a request to open a free memory block for the storage of data. The memory management module determines a frequency with which the data is updated. The memory management module then opens a memory block of a first portion a free block list that is associated with low program/erase cycle counts in response to determining that the data will be frequently updated or opens a memory block of a second different portion of the free block list that is associated with high program/erase cycle counts in response to determining that the data is not frequently updated. The memory management module then stores the data in the open memory block of the non-volatile memory.
    Type: Application
    Filed: December 29, 2014
    Publication date: June 30, 2016
    Applicant: SanDisk Technologies Inc.
    Inventor: Leena Patel
  • Patent number: 9378832
    Abstract: Techniques for reversing damage caused by program-erase cycles in charge-trapping memory to improve long term data retention. A recovery process improves the data retention of a block of memory cells by programming the memory cells to a relatively high threshold voltage and enforcing a time period of several minutes or hours in which the memory cells are inactive and remain at the relatively high Vth levels. Damage such as traps in the memory cells is essentially healed or annealed out during this inactive period. All of the memory cells can be healed at the same time and by relatively equal amounts. At the conclusion of the recovery process, the block is returned to a pool of available blocks. In one approach, an amount of recovery is measured and the period of inactivity is continued for an amount of time which is based on the amount of recovery.
    Type: Grant
    Filed: December 10, 2014
    Date of Patent: June 28, 2016
    Assignee: SanDisk Technologies Inc.
    Inventors: Ching-Huang Lu, Zhengyi Zhang, Wei Zhao, Yingda Dong, Jian Chen
  • Patent number: 9379124
    Abstract: A method of making a monolithic three dimensional NAND string which contains a semiconductor channel and a plurality of control gate electrodes, includes selectively forming a plurality of discrete charge storage regions using atomic layer deposition. The plurality of discrete charge storage regions includes at least one of a metal or an electrically conductive metal oxide.
    Type: Grant
    Filed: June 25, 2014
    Date of Patent: June 28, 2016
    Assignee: SANDISK TECHNOLOGIES INC.
    Inventors: Rahul Sharangpani, Raghuveer S. Makala, Thomas Jongwan Kwon, Senaka Kanakamedala, George Matamis
  • Patent number: 9379246
    Abstract: Three-dimensional (3D) non-volatile memory arrays having a vertically-oriented thin film transistor (TFT) select device and method of fabricating such a memory are described. The vertically-oriented TFT may be used as a vertical bit line selection device to couple a global bit line to a vertical bit line. A select device pillar includes a body and upper and lower source/drain regions. At least one gate is separated horizontally from the select device pillar by a gate dielectric. Beneath each gate, a single gap fill dielectric layer extends vertically from a lower surface of the gate, at least partially separating the gate from the underlying global bit line. Between horizontally adjacent pillars, this same dielectric layer extends from its same lower level beneath the gates vertically to a level of the upper source/drain region.
    Type: Grant
    Filed: March 5, 2014
    Date of Patent: June 28, 2016
    Assignee: SanDisk Technologies Inc.
    Inventor: Seiji Shimabukuro
  • Patent number: 9379132
    Abstract: Methods of making monolithic three-dimensional memory devices include performing a first etch to form a memory opening and a second etch using a different etching process to remove a damaged portion of the semiconductor substrate from the bottom of the memory opening. A single crystal semiconductor material is formed over the substrate in the memory opening using an epitaxial growth process. Additional embodiments include improving the quality of the interface between the semiconductor channel material and the underlying semiconductor layers in the memory opening which may be damaged by the bottom opening etch, including forming single crystal semiconductor channel material by epitaxial growth from the bottom surface of the memory opening and/or oxidizing surfaces exposed to the bottom opening etch and removing the oxidized surfaces prior to forming the channel material. Monolithic three-dimensional memory devices formed by the embodiment methods are also disclosed.
    Type: Grant
    Filed: October 24, 2014
    Date of Patent: June 28, 2016
    Assignee: SANDISK TECHNOLOGIES INC.
    Inventors: Sateesh Koka, Raghuveer S. Makala, Yanli Zhang, Senaka Kanakamedala, Rahul Sharangpani, Yao-Sheng Lee, George Matamis
  • Patent number: 9378814
    Abstract: Methods for precharging bit lines using closed-loop feedback are described. In one embodiment, a sense amplifier may include a bit line precharge circuit for setting a bit line to a read voltage prior to sensing a memory cell connected to the bit line. The bit line precharge circuit may include a first transistor in a source-follower configuration with a first gate and a first source node electrically coupled to the bit line. By applying local feedback from the first source node to the first gate, the bit line settling time may be reduced. In some cases, a first voltage applied to the first gate may be determined based on a first current drawn from the first bit line. Thus, the first voltage applied to the first gate may vary over time depending on the conductivity of a selected memory cell connected to the bit line.
    Type: Grant
    Filed: May 20, 2014
    Date of Patent: June 28, 2016
    Assignee: SANDISK TECHNOLOGIES INC.
    Inventors: Chang Siau, Xiaowei Jiang, Yingchang Chen
  • Patent number: 9379120
    Abstract: High-density semiconductor memory utilizing metal control gate structures and air gap electrical isolation between discrete devices in these types of structures are provided. During gate formation and definition, etching the metal control gate layer(s) is separated from etching the charge storage layer to form protective sidewall spacers along the vertical sidewalls of the metal control gate layer(s). The sidewall spacers encapsulate the metal control gate layer(s) while etching the charge storage material to avoid contamination of the charge storage and tunnel dielectric materials. Electrical isolation is provided, at least in part, by air gaps that are formed in the row direction and/or air gaps that are formed in the column direction.
    Type: Grant
    Filed: July 22, 2013
    Date of Patent: June 28, 2016
    Assignee: SanDisk Technologies Inc.
    Inventors: Vinod Robert Purayath, Tuan Pham, Hiroyuki Kinoshita, Yuan Zhang, Henry Chin, James K Kai, Takashi W Orimoto, George Matamis, Henry Chien
  • Publication number: 20160181272
    Abstract: Disclosed herein are techniques for fabricating 3D NAND memory devices having a mono-crystalline silicon semiconductor vertical NAND channel. Memory holes are formed in horizontal layers of material above a substrate. A vertically-oriented NAND string is formed in each of the memory holes. Forming the vertically-oriented NAND string channel comprises growing monolithic crystalline silicon upwards in the memory hole from the substrate through all of the plurality of horizontal layers of material. Vapor phase epitaxial growth may be used grow the monolithic crystalline silicon upwards from the bottom of the vertically-oriented NAND channel. Alternatively, a nanowire of monolithic crystalline silicon is synthesized in the memory hole from the substrate at the bottom of the vertically-oriented NAND channel upwards to the top of the vertically-oriented NAND channel.
    Type: Application
    Filed: December 18, 2014
    Publication date: June 23, 2016
    Applicant: SanDisk Technologies Inc.
    Inventors: Peter Rabkin, Jayavel Pachamuthu, Johann Alsmeier, Masaaki Higashitani
  • Publication number: 20160182044
    Abstract: Techniques for trimming an on chip ZQ calibration resistor are disclosed. The on chip ZQ calibration resistor alleviates the need for an external ZQ calibration resistor. The on chip ZQ calibration resistor allows for a faster ZQ calibration. The trimming of on chip ZQ calibration resistor may be used to account for process variation. A correction mechanism may be used to account for temperature variation. Some of the circuitry that is used for ZQ calibration is also used for trimming the on-chip calibration resistor. This circuitry may include operational amplifiers, current mirrors, transistors, etc. The dual use of the circuitry can eliminate offset errors in an operational amplifier. The dual use can eliminate current mirror mismatch. Therefore, the trimming accuracy may be improved. The dual use also reduces the amount of circuitry that is needed for trimming the on chip ZQ calibration resistor. Thus, transistor count and chip size is reduced.
    Type: Application
    Filed: December 11, 2015
    Publication date: June 23, 2016
    Applicant: SanDisk Technologies Inc.
    Inventors: Sravanti Addepalli, Sridhar Yadala