Patents by Inventor Dana Lee
Dana Lee has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 12609172Abstract: A non-volatile memory system is configured to perform a multiplane erase process that concurrently erases groups of memory cells in multiple planes. Based on that multiplane erase process, the memory system determines that a first group of memory cells in a first plane of the multiple planes is slow to erase. As a result, the system will perform one or more multiplane erase processes for the groups of memory cells in multiple planes without erasing the first group of memory cells in the first plane as part of the multiplane erase process(es).Type: GrantFiled: July 25, 2023Date of Patent: April 21, 2026Assignee: Sandisk Technologies, Inc.Inventors: Liang Li, Dandan Yi, Dana Lee
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Patent number: 12354678Abstract: A non-volatile memory system performs an erase process followed by a program process to program blocks of memory cells. The erase process comprises erasing followed by erase verification. The system recovers data and records a strike for blocks that fail a read process. In response to a particular block having a strike, the system performs an odd/even compare process during the erase process for the particular blocks having the strike such that the odd/even compare process comprises determining whether a number of memory cells connected to even word lines that have a different erase verify result than memory cells connected to odd word lines is greater than a defect test threshold. The system retires blocks from further use for storing host data that fail the odd/even compare process even if the block passes erase verification.Type: GrantFiled: April 26, 2022Date of Patent: July 8, 2025Assignee: Sandisk Technologies, Inc.Inventors: Jayavel Pachamuthu, Dana Lee, Jiahui Yuan
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Publication number: 20240312538Abstract: A non-volatile memory system is configured to perform a multiplane erase process that concurrently erases groups of memory cells in multiple planes. Based on that multiplane erase process, the memory system determines that a first group of memory cells in a first plane of the multiple planes is slow to erase. As a result, the system will perform one or more multiplane erase processes for the groups of memory cells in multiple planes without erasing the first group of memory cells in the first plane as part of the multiplane erase process(es).Type: ApplicationFiled: July 25, 2023Publication date: September 19, 2024Applicant: Western Digital Technologies, Inc.Inventors: Liang Li, Dandan Yi, Dana Lee
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Patent number: 11810628Abstract: When erasing multiple sub-blocks of a block, erase verify is performed for memory cells connected to even word lines to generate even results and for memory cells connected to odd word lines to generate odd results. The even results and the odd results are used to determine that the erase verify process successfully completed. For each NAND string of a first sub-block, a last even result for the NAND string is compared to a last odd result for the NAND string. Despite the determination that the first sub-block successfully completed erase verify, the erasing failed for the first sub-block because the number of NAND strings that have the last even result different than the last odd result is greater than a limit. The system determines that one or more additional sub-blocks also failed erasing based on and in response to determining that the first sub-block failed erasing.Type: GrantFiled: February 16, 2022Date of Patent: November 7, 2023Assignee: SanDisk Technologies LLCInventors: Jayavel Pachamuthu, Dana Lee
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Publication number: 20230260582Abstract: When erasing multiple sub-blocks of a block, erase verify is performed for memory cells connected to even word lines to generate even results and for memory cells connected to odd word lines to generate odd results. The even results and the odd results are used to determine that the erase verify process successfully completed. For each NAND string of a first sub-block, a last even result for the NAND string is compared to a last odd result for the NAND string. Despite the determination that the first sub-block successfully completed erase verify, the erasing failed for the first sub-block because the number of NAND strings that have the last even result different than the last odd result is greater than a limit. The system determines that one or more additional sub-blocks also failed erasing based on and in response to determining that the first sub-block failed erasing.Type: ApplicationFiled: February 16, 2022Publication date: August 17, 2023Applicant: SanDisk Technologies LLCInventors: Jayavel Pachamuthu, Dana Lee
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Publication number: 20230058836Abstract: A non-volatile memory system performs an erase process followed by a program process to program blocks of memory cells. The erase process comprises erasing followed by erase verification. The system recovers data and records a strike for blocks that fail a read process. In response to a particular block having a strike, the system performs an odd/even compare process during the erase process for the particular blocks having the strike such that the odd/even compare process comprises determining whether a number of memory cells connected to even word lines that have a different erase verify result than memory cells connected to odd word lines is greater than a defect test threshold. The system retires blocks from further use for storing host data that fail the odd/even compare process even if the block passes erase verification.Type: ApplicationFiled: April 26, 2022Publication date: February 23, 2023Applicant: SANDISK TECHNOLOGIES LLCInventors: Jayavel Pachamuthu, Dana Lee, Jiahui Yuan
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Publication number: 20220399072Abstract: An apparatus includes one or more control circuits configured to connect to a plurality of non-volatile memory cells arranged along word lines. The one or more control circuits are configured to receive a plurality of encoded portions of data to be programmed in non-volatile memory cells of a target word line, each encoded portion of data encoded according to an Error Correction Code (ECC) encoding scheme, and arrange the plurality of encoded portions of data in a plurality of rows of data latches corresponding to a plurality of logical pages such that each encoded portion of data is distributed across two or more rows of data latches. The one or more control circuits are also configured to program the distributed encoded portions of data from the plurality of rows of data latches into non-volatile memory cells along a target word line.Type: ApplicationFiled: June 15, 2021Publication date: December 15, 2022Applicant: SanDisk Technologies LLCInventors: Hua-Ling Cynthia Hsu, Dana Lee
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Patent number: 11482531Abstract: A three-dimensional memory device includes an alternating stack of insulating layers and electrically conductive layers located over a substrate, memory stack structures extending through the alternating stack. Each of the memory stack structures includes a vertical semiconductor channel, a tunneling dielectric layer, and a vertical stack of memory elements located at levels of the electrically conductive layers between a respective vertically neighboring pair of the insulating layers. Each of the memory elements includes a first memory material portion, and a second memory material portion that is vertically spaced from and is electrically isolated from the first memory material portion by at least one blocking dielectric material portion.Type: GrantFiled: February 8, 2021Date of Patent: October 25, 2022Assignee: SANDISK TECHNOLOGIES LLCInventors: Ramy Nashed Bassely Said, Jiahui Yuan, Senaka Kanakamedala, Raghuveer S. Makala, Dana Lee
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Publication number: 20220254797Abstract: A three-dimensional memory device includes an alternating stack of insulating layers and electrically conductive layers located over a substrate, memory stack structures extending through the alternating stack. Each of the memory stack structures includes a vertical semiconductor channel, a tunneling dielectric layer, and a vertical stack of memory elements located at levels of the electrically conductive layers between a respective vertically neighboring pair of the insulating layers. Each of the memory elements includes a first memory material portion, and a second memory material portion that is vertically spaced from and is electrically isolated from the first memory material portion by at least one blocking dielectric material portion.Type: ApplicationFiled: February 8, 2021Publication date: August 11, 2022Inventors: Ramy Nashed Bassely SAID, Jiahui YUAN, Senaka KANAKAMEDALA, Raghuveer S. MAKALA, Dana LEE
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Patent number: 11194523Abstract: A data storage device includes a non-volatile memory and a controller coupled to the non-volatile memory. The controller is operable to measure a first threshold voltage (VT) of a memory cell under a first parameter at a read temperature and measure a second VT of the memory cell under a second parameter at the read temperature in which the first parameter is different from the second parameter. A VT correction term for the memory cell is determined based upon the first VT measurement and the second VT measurement. A read VT of the memory cell is adjusted by using the VT correction term.Type: GrantFiled: January 24, 2020Date of Patent: December 7, 2021Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.Inventors: Stella Achtenberg, Eran Sharon, David Rozman, Alon Eyal, Idan Alrod, Dana Lee
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Patent number: 11081190Abstract: A method for data recovery in a memory array of a non-volatile memory system, wherein the method comprises detecting an electrical short between a word line (WL) of a memory cell transistor and a local source line (LI) of a memory structure of the array, increasing an initial voltage bias at the local source line to a second voltage bias that exceeds a threshold voltage of the shorted memory cell transistor and a voltage level of a bit line of the memory structure, thereby causing a sensing current to flow in a direction from the local source line to the bit line, and sensing at a sense amplifier of the memory structure the sensing current.Type: GrantFiled: May 22, 2020Date of Patent: August 3, 2021Assignee: SanDiskTechnologies LLCInventors: Abhinav Anand, Young Pil Kim, Dana Lee
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Publication number: 20200159465Abstract: A data storage device includes a non-volatile memory and a controller coupled to the non-volatile memory. The controller is operable to measure a first threshold voltage (Vt) of a memory cell under a first parameter at a read temperature and measure a second Vt of the memory cell under a second parameter at the read temperature in which the first parameter is different from the second parameter. A Vt correction term for the memory cell is determined based upon the first Vt measurement and the second Vt measurement. A read Vt of the memory cell is adjusted by using the Vt correction term.Type: ApplicationFiled: January 24, 2020Publication date: May 21, 2020Inventors: Stella ACHTENBERG, Eran SHARON, David ROZMAN, Alon EYAL, Idan ALROD, Dana LEE
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Patent number: 10642681Abstract: A device includes a memory device and a controller. The memory device includes read/write circuitry and a plurality of memory dies. The controller is coupled to the memory device. The controller is configured to, responsive to determining that at least one storage element of a first die of the plurality of memory dies has a characteristic indicative of an aging condition, increase the temperature of the first die by performing memory operations on the first die until detecting a condition related to the temperature.Type: GrantFiled: May 3, 2018Date of Patent: May 5, 2020Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.Inventors: Preeti Yadav, Prasanna Desai Sudhir Rao, Smita Aggarwal, Dana Lee
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Patent number: 10564900Abstract: A data storage device includes a non-volatile memory and a controller coupled to the non-volatile memory. The controller is operable to measure a first threshold voltage (Vt) of a memory cell under a first parameter at a read temperature and measure a second Vt of the memory cell under a second parameter at the read temperature in which the first parameter is different from the second parameter. A Vt correction term for the memory cell is determined based upon the first Vt measurement and the second Vt measurement. A read Vt of the memory cell is adjusted by using the Vt correction term.Type: GrantFiled: June 11, 2018Date of Patent: February 18, 2020Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.Inventors: Stella Achtenberg, Eran Sharon, David Rozman, Alon Eyal, Idan Alrod, Dana Lee
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Patent number: 10558381Abstract: Apparatuses, systems, methods, and computer program products are disclosed for dynamic read table generation. One apparatus includes a set of non-volatile storage cells. A controller for a set of non-volatile storage cells is configured to, in response to unsuccessfully reading a storage cell of the set of non-volatile storage cells using a parameter, read the storage cell using one or more shifted values. A controller for a set of non-volatile storage cells is configured to, in response to successfully reading a storage cell using one or more shifted values, add the one or more shifted values to a storage device.Type: GrantFiled: December 16, 2016Date of Patent: February 11, 2020Assignee: SanDisk Technologies LLCInventors: Henry Chin, Sateesh Desireddi, Dana Lee, Ashwin D T, Harshul Gupta, Parth Amin, Jia Li
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Patent number: 10446242Abstract: A device includes a memory and a controller coupled to the memory. The controller is configured to determine a temperature-based value of a search parameter in response to detecting that an error rate of a codeword read from the memory exceeds a threshold error rate. The controller is further configured to iteratively modify one or more memory access parameters associated with reducing temperature-dependent threshold voltage variation and to re-read the codeword using the modified one or more memory access parameters.Type: GrantFiled: June 9, 2017Date of Patent: October 15, 2019Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.Inventors: Stella Achtenberg, Eran Sharon, David Rozman, Alon Eyal, Idan Alrod, Dana Lee
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Patent number: 10379754Abstract: A device includes a memory device and a controller. The controller is coupled to the memory device. The controller is configured to, in response to receiving a request to perform a memory access at the memory device, determine that the memory device has a characteristic indicative of a temperature crossing. The controller is also configured to, in response to determining that the memory device has the characteristic indicative of the temperature crossing, determine that the memory device satisfies an availability criterion. The controller is further configured to, in response to determining that the memory device satisfies the availability criterion, increase a temperature of the memory device by performing memory operations on the memory device until detecting a condition related to the temperature.Type: GrantFiled: January 20, 2018Date of Patent: August 13, 2019Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.Inventors: Philip David Reusswig, Nian Niles Yang, Grishma Shah, Deepak Raghu, Preeti Yadav, Prasanna Desai Sudhir Rao, Smita Aggarwal, Dana Lee
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Patent number: 10355007Abstract: A memory stack structure includes a cavity including a back gate electrode, a back gate dielectric, a semiconductor channel, and at least one charge storage element. In one embodiment, a line trench can be filled with a memory film layer, and a plurality of semiconductor channels can straddle the line trench. The back gate electrode can extend along the lengthwise direction of the line trench. In another embodiment, an isolated memory opening overlying a patterned conductive layer can be filled with a memory film, and the back gate electrode can be formed within a semiconductor channel and on the patterned conductive layer. A dielectric cap portion electrically isolates the back gate electrode from a drain region. The back gate electrode can be employed to bias the semiconductor channel, and to enable sensing of multinary bits corresponding to different amounts of electrical charges stored in a memory cell.Type: GrantFiled: December 15, 2016Date of Patent: July 16, 2019Assignee: SANDISK TECHNOLOGIES LLCInventors: Xiying Costa, Dana Lee, Yanli Zhang, Johann Alsmeier, Yingda Dong, Akira Matsudaira
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Patent number: 10289343Abstract: A device includes a memory device and a controller. The controller is coupled to the memory device. The controller is configured to, in response to receiving a request to perform a memory access at the memory device, determine that the memory device has a characteristic indicative of a temperature crossing. The controller is also configured to, in response to the determination, increase a temperature of the memory device by performing memory operations on the memory device until detecting a condition related to the temperature.Type: GrantFiled: January 22, 2018Date of Patent: May 14, 2019Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.Inventors: Preeti Yadav, Prasanna Desai Sudhir Rao, Smita Aggarwal, Dana Lee
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Patent number: 10249382Abstract: Techniques are described for determining whether a non-volatile memory device is defective due to a word line that programs too fast, leading to an uncorrectable amount of data errors when programing data to the word line. In one set of examples, a set of memory cells are programmed by a series of voltage pulses applied along a word line without locking out the set of memory cells. A verify operation is then performed to see if the number of memory cells programmed above the verify level is too large and, if so, an error status is returned. In other examples, a lower limit on the number of voltage pulses needed to complete programming is introduced, and if the programming completes in less than this number of voltage pulses, an error status returned. A lower limit on the number of voltage pulses can be on a state by state basis or for all data states to complete.Type: GrantFiled: August 22, 2017Date of Patent: April 2, 2019Assignee: SanDisk Technologies LLCInventors: Dana Lee, Ekam Singh, Ashish Ghai, Kalpana Vakati