Patents Assigned to SanDisk Technologies LLC
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Publication number: 20210272639Abstract: A memory apparatus and method of operation is provided. The apparatus includes a plurality of memory cells coupled to a control circuit. The control circuit is configured to receive data indicating a data state for each memory cell of a set of memory cells of the plurality of memory cells and program, in multiple programming loops, the set of memory cells according to the data indicating the data state for each memory cell of the set of memory cells. The control circuit is further configured to determine that the programming of the set of memory cells is in a last programming loop of the multiple programming loops and in response to the determination, receive data indicating a data state for each memory cell of another set of memory cells of the plurality of memory cells.Type: ApplicationFiled: February 27, 2020Publication date: September 2, 2021Applicant: SanDisk Technologies LLCInventors: Piyush A. Dhotre, Sahil Sharma, Niles Yang, Phil Reusswig
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Patent number: 11107540Abstract: Techniques for reducing program disturb of memory cells which are formed in a NAND string extending in a lower tier and an upper tier of a stack, the lower tier including a first plurality of memory cells and the upper tier including a second plurality of memory cells, wherein each memory cell of the first and second pluralities of memory cells is connected to a respective word line. The NAND string includes a joint region formed of a dielectric material and disposed between the lower tier and the upper tier of the stack; a first non-data memory cell adjacent to and below the joint region; a second non-data memory cell adjacent to and above the joint region; and a conductive gate connected to the first non-data memory cell and the second non-data memory cell.Type: GrantFiled: February 14, 2020Date of Patent: August 31, 2021Assignee: Sandisk Technologies LLCInventors: Jayavel Pachamuthu, Dengtao Zhao
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Publication number: 20210264964Abstract: This disclosure relates to apparatuses and a method for retaining a bias in a NAND string channel during source-side precharge. The apparatuses include a memory array and a die controller configured to mitigate formation of a potential gradient in the channel of the memory array NAND strings during a program storage operation. To this end, a plurality of source-side select gates is activated, then each of the plurality of source side dummy word line select gates is activated. Next, a NAND string channel is biased by biasing the source line coupled to the NAND string by the plurality of source-side select gates. Finally, the plurality of source-side select gates and the plurality of source side dummy word line select gates are discharged such that the channel maintains an electrical path to the source line.Type: ApplicationFiled: February 24, 2020Publication date: August 26, 2021Applicant: SanDisk Technologies LLCInventors: Sarath Puthenthermadam, Yu-Chung Lien, Huai-Yuan Tseng
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Patent number: 11101326Abstract: A non-volatile memory uses phase change memory (PCM) cells in a three dimensional vertical cross-point structure, in which multiple layers of word lines run in a horizontal direction and bit lines run in a vertical direction. The memory cells are located in a recessed region of the word lines and are separated from the bit line by an ovonic threshold switch. A surfactant lining of the word line recess in which the phase change memory material is placed improves stability of the resistance state of the memory cells, allowing for improved multi-state operation.Type: GrantFiled: June 9, 2020Date of Patent: August 24, 2021Assignee: SanDisk Technologies LLCInventors: Federico Nardi, Christopher J Petti, Gerrit Jan Hemink
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Patent number: 11099784Abstract: Apparatuses and techniques are described for reading crosspoint arrays of memory cells with high bandwidth and a relatively small page buffer. Multiple crosspoint arrays (XPAs) are read in parallel, with one memory cell per XPA being read, in a bank of XPAs. To reduce the read time, a row can be selected for the XPAs, after which memory cells in different columns are read, one column at a time, while the same row is selected. This avoids the need to transmit commands and a row address for re-selecting the row in each successive read operation. The XPAs may be ungrouped, or one XPA may be accessible at a time in a group. In one option, the XPAs are arranged in sets, either individually or in groups, and one set is accessible at a time.Type: GrantFiled: December 17, 2019Date of Patent: August 24, 2021Assignee: SanDisk Technologies LLCInventors: Won Ho Choi, Ward Parkinson, Raj Ramanujan, Martin Lueker-Boden
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Publication number: 20210257037Abstract: A method for memory program verification includes performing a write operation on memory cells of a memory device. The method also includes identifying memory strings associated with respective memory cells of the memory cells. The method also includes identifying a first memory string of the memory strings. The method also includes disabling a portion of a write verification for the first memory string. The method also includes enabling the portion of the write verification for other memory strings of the memory strings. The method also includes performing at least the portion of the write verification operation on write verification enabled memory strings.Type: ApplicationFiled: February 18, 2020Publication date: August 19, 2021Applicant: SanDisk Technologies LLCInventors: Zhiping Zhang, Huai-Yuan Tseng, Dengtao Zhao, Deepanshu Dutta
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Publication number: 20210257039Abstract: Apparatuses and techniques are described for periodically refreshing word line voltages in a block of memory cells based on the susceptibility of the block to read errors. One source of read errors is delayed read disturb which results from a low word line voltage during idle periods of the memory device. In one aspect, periodic refresh operations are optimized based on factors such as a number of bits per cell in the block and number of program-erase (P-E) cycles. For example, at high P-E cycles, the amplitude of a refresh voltage for a single-level cell (SLC) block can be 0 V or lower while the amplitude of a refresh voltage for a multi-level cell (MLC) block can be an intermediate voltage between 0 V and a pass voltage.Type: ApplicationFiled: February 13, 2020Publication date: August 19, 2021Applicant: SanDisk Technologies LLCInventors: Abhijith Prakash, Jiahui Yuan
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Patent number: 11094674Abstract: A semiconductor device is disclosed including a memory module formed from a pair of semiconductor dies mounted face to face to each other at the wafer level, mechanically resulting in the die pair having a minimum warpage. An electronic component may be bonded to an exposed surface of one of the semiconductor dies.Type: GrantFiled: March 12, 2020Date of Patent: August 17, 2021Assignee: SanDisk Technologies LLCInventors: Nagesh Vodrahalli, Shrikar Bhagath, Rama Shukla
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Publication number: 20210249073Abstract: An apparatus is provided that includes a plurality of data arrays each comprising first memory cells, a plurality of read reference arrays each comprising second memory cells, a plurality of write reference arrays each comprising third memory cells, an access block comprising a memory cell from each of the plurality of data arrays, each of the plurality of read reference arrays, and each of the plurality of write reference arrays, and a memory controller. The memory controller is configured to determine a read threshold voltage to compensate a drift of a threshold voltage of the first memory cells, wherein the read threshold voltage is determined based on threshold voltages of a plurality of second memory cells, and a read offset voltage to compensate an offset voltage of the first memory cells, wherein the read offset voltage is determined based on offset voltages of a plurality of second memory cells.Type: ApplicationFiled: April 30, 2021Publication date: August 12, 2021Applicant: SanDisk Technologies LLCInventors: Michael K. Grobis, Daniel Bedau
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Patent number: 11087803Abstract: An apparatus including a memory structure comprising non-volatile memory cells and a microcontroller. The microcontroller is configured to output Core-Timing-Control (CTC) signals. The CTC signals are used to control voltages that are applied in the memory structure. For example, CTC signals may be used to control the timing of voltages applied to word lines, bit lines, select lines, and other elements or control lines in the memory core. The microcontroller is configured to output CTC signals having many different variations under various modes/parameter conditions. The apparatus may include storage containing reaction data according to dynamic conditions. The microcontroller may be configured to lookup or compute the CTC signals based on the dynamic conditions and the reaction data. Various data storage formats are disclosed, which can be used to efficiently store many varieties of data with minimum usage of memory.Type: GrantFiled: June 18, 2020Date of Patent: August 10, 2021Assignee: SanDisk Technologies LLCInventors: Yuheng Zhang, Po-Shen Lai, Hao Su
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Patent number: 11087800Abstract: A sense amplifier architecture is presented that can reduce sensing times by being able to sense smaller voltage swings between an ON memory cell and an OFF memory cell. The sense amplifier includes a sensing capacitor that, on one side, is connectable to multiple bit lines and, on the other side, to a main sense amplifier section. The main section includes a latch formed of a pair of inverters that has an input connected to the capacitor and an output that is connected to the other side of the capacitor by a third inverter. To pre-charge the latch, the input and output nodes are shorted and then the capacitor is connected to discharge the capacitor through a selected memory cell based on whether it is ON or OFF. A programming data latch for each bit line can bias the bit line to either a program enable or program inhibit level.Type: GrantFiled: April 10, 2020Date of Patent: August 10, 2021Assignee: SanDisk Technologies LLCInventor: Hiroki Yabe
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Patent number: 11086539Abstract: Consecutive logical block addresses (LBAs) are mapped to consecutive good blocks in a sequence of blocks in a memory device. For each bad block, a mapping process substitutes a next available good block. For a selected LBA, the mapping process determines a number X>1 of bad blocks before, and including, a corresponding block in the sequence, a number Y of bad blocks in the X blocks after the corresponding block in the sequence, and maps the LBA to a block which is X+Y blocks after the corresponding block, or, if the block which is X+Y blocks after the corresponding block is a bad block, to a next good block. The mapping technique can be used for a sequence of blocks in a trimmed die, where a bad block register stores physical block addresses of the trimmed away blocks.Type: GrantFiled: October 21, 2019Date of Patent: August 10, 2021Assignee: SanDisk Technologies LLCInventors: Dat Tran, Loc Tu, Kirubakaran Periyannan
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Publication number: 20210241836Abstract: Techniques are described for optimizing the peak current during a program operation by controlling a timing and ramp rate of a program-inhibit voltage signal as a function of a program loop number and/or program progress. A transition voltage between a regulated ramp up rate and an unregulated ramp up rate can also be adjusted. For initial and final sets of program loops in a program operation, the ramp up of the program-inhibit voltage signal can occur early so that it overlaps with operations of sense circuits in updating their latches based on results from a verify test in a previous program loop. For an intermediate set of program loops, the overlap is avoided. The ramp up rate can be larger and the transition voltage smaller for the initial and final sets of program loops compared to the intermediate set of program loops.Type: ApplicationFiled: January 31, 2020Publication date: August 5, 2021Applicant: SanDisk Technologies LLCInventors: Yu-Chung Lien, Huai-Yuan Tseng, Deepanshu Dutta
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Patent number: 11081180Abstract: Techniques for fast programming and read operations for memory cells. A first set of bit lines is connected to a first set of NAND strings and is interleaved with a second set of bit lines connected to a second set of NAND strings. The first set of NAND strings can be programmed by driving a voltage on the first set of bit lines while floating a voltage on the second set of bit lines, to reduce an inter-bit line capacitance and provide a relatively high access speed and a relatively low storage density (e.g., bits per memory cell). The second set of NAND strings can be programmed by concurrently driving a voltage on the first and second sets of bit lines, to provide a relatively low access speed and a relatively high storage density.Type: GrantFiled: April 7, 2020Date of Patent: August 3, 2021Assignee: SanDisk Technologies LLCInventors: Xiang Yang, Huai-Yuan Tseng, Deepanshu Dutta
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Patent number: 11081474Abstract: Systems and methods for dynamically assigning memory array die to CMOS die of a plurality of stacked die during memory operations are described. The plurality of stacked die may be vertically stacked and connected together via one or more vertical through-silicon via (TSV) connections. The memory array die may only comprise memory cell structures (e.g., vertical NAND strings) without column decoders, row decoders, charge pumps, sense amplifiers, control circuitry, page registers, or state machines. The CMOS die may contain support circuitry necessary for performing the memory operations, such as read and write memory operations. The one or more vertical TSV connections may allow each memory array die of the plurality of stacked die to communicate with or be electrically connected to one or more CMOS die of the plurality of stacked die.Type: GrantFiled: April 29, 2020Date of Patent: August 3, 2021Assignee: SanDisk Technologies LLCInventors: Tung Thanh Hoang, Martin Lueker-Boden, Anand Kulkarni
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Patent number: 11081193Abstract: Technology is disclosed herein for correcting skew between data signals and a clock signal. In one aspect, a memory system has a delay circuit having delay blocks, with each delay block having one or more inverters. The delay circuit is configured to pass a data signal through either an odd number of the inverters or an even number of the inverters to produce a delayed data signal. The memory system has a skew correction circuit configured to control the number of inverters in the delay circuit through which the data signal is passed in order to correct skew between the data signal and the clock signal. The memory system has a polarity correction circuit configured to invert the data signal in the event that the delay circuit passed the data signal through the odd number of the inverters.Type: GrantFiled: June 16, 2020Date of Patent: August 3, 2021Assignee: SanDisk Technologies LLCInventor: Tianyu Tang
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Patent number: 11081197Abstract: A methodology and structure for performing an erase verify in non-volatile memory is described. Both the odd wordlines and the even wordlines are driven to a high voltage level. This can be done simultaneously. The simultaneous charging of both the odd wordlines and the even wordlines, even when the erase verify will occur on only one of the odd or even wordlines reduces RC delay in the charging of the wordlines. After the odd and even wordlines are charged, then one set of wordlines, either the odd or even wordlines, is dropped to the erase verify voltage. The erase sense operation is then performed.Type: GrantFiled: October 9, 2020Date of Patent: August 3, 2021Assignee: SanDisk Technologies LLCInventors: Xiang Yang, Yu-Chung Lien
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Patent number: 11081162Abstract: This disclosure relates to apparatuses and a method for retaining a bias in a NAND string channel during source-side precharge. The apparatuses include a memory array and a die controller configured to mitigate formation of a potential gradient in the channel of the memory array NAND strings during a program storage operation. To this end, a plurality of source-side select gates is activated, then each of the plurality of source side dummy word line select gates is activated. Next, a NAND string channel is biased by biasing the source line coupled to the NAND string by the plurality of source-side select gates. Finally, the plurality of source-side select gates and the plurality of source side dummy word line select gates are discharged such that the channel maintains an electrical path to the source line.Type: GrantFiled: February 24, 2020Date of Patent: August 3, 2021Assignee: SanDisk Technologies LLCInventors: Sarath Puthenthermadam, Yu-Chung Lien, Huai-Yuan Tseng
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Patent number: 11081185Abstract: A memory device is disclosed configured to share word line switches (WLSW) between each word line of two adjacent erase blocks. The word lines are driven from both sides of the memory array to reduces resistive-capacitive (RC) loading during pre-charge/ramp-up periods and during discharge/ramp-down periods for various storage operations. The dual-sided driving of signals combines with synergistic erase block size management to lower read latency (tR) for non-volatile memory media.Type: GrantFiled: June 18, 2019Date of Patent: August 3, 2021Assignee: SanDisk Technologies LLCInventors: Hardwell Chibvongodze, Masatoshi Nishikawa
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Patent number: 11079824Abstract: Systems and methods for power distribution are disclosed. A system includes a first power domain that supplies current to an integrated circuit at a first voltage level, a second power domain that supplies current to the integrated circuit at a second voltage level, and a current distribution component that is connected to the first power domain and connectable to the second power domain and senses a metric comprising a first current level or a first voltage level drawn from the first power domain, determines whether the metric exceeds a first threshold, and in response to determining that the metric exceeds the first threshold, electrically connects the second power domain to the integrated circuit to supply additional current such that an aggregate current level received by the integrated circuit comprises current from the first power domain and the additional current from the second power domain.Type: GrantFiled: April 22, 2019Date of Patent: August 3, 2021Assignee: SanDisk Technologies LLCInventors: Nitin Gupta, Bhavin Odedara, Raghu Voleti