Patents Assigned to SanDisk Technologies LLC
  • Patent number: 12148478
    Abstract: A non-volatile memory system comprises a plurality of non-volatile memory cells divided into three or more tiers. The memory cells can be programmed, erased and read. In order to achieve uniform erase speed for the three or more tiers, the erase process comprises applying a larger voltage bias to control gates of non-volatile memory cells in the outer tiers than the voltage bias applied to control gates of non-volatile memory cells in one or more inner tiers.
    Type: Grant
    Filed: September 26, 2022
    Date of Patent: November 19, 2024
    Assignee: SanDisk Technologies LLC
    Inventors: Xiang Yang, Masaaki Higashitani, Abhijith Prakash, Dengtao Zhao
  • Patent number: 12148710
    Abstract: A three-dimensional memory device includes a first alternating stack of first word lines and first insulating layers, first memory stack structures vertically extending through the first alternating stack, a second alternating stack of second word lines and second insulating layers, second memory stack structures vertically extending through the second alternating stack, plural backside trench fill structures located between the first alternating stack and the second alternating stack, and a bridge region located between the plural backside trench fill structures and between the between the first alternating stack and the second alternating stack. At least one insulating layer extends continuously through the first alternating stack, the second alternating stack, and the bridge region.
    Type: Grant
    Filed: October 26, 2021
    Date of Patent: November 19, 2024
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Koichi Matsuno, Johann Alsmeier
  • Patent number: 12147695
    Abstract: A memory system performs an erase process for the non-volatile memory cells including performing erase verify for the non-volatile memory cells. The erase verify comprises comparing threshold voltages of the non-volatile memory cells to an erase verify reference voltage and determining whether an amount of the non-volatile memory cells having a threshold voltage greater than the erase verify reference voltage is less than an allowed bit count. During the erase process, the system compares threshold voltages of the non-volatile memory cells to an intermediate reference voltage that is greater than the erase verify reference voltage and determines an amount of non-volatile memory cells having threshold voltages greater than the intermediate reference voltage. The Allowed Bit Count is increased (during the erase process) by the amount of non-volatile memory cells having threshold voltages greater than the intermediate reference voltage.
    Type: Grant
    Filed: July 25, 2023
    Date of Patent: November 19, 2024
    Assignee: SanDisk Technologies LLC
    Inventors: Longju Liu, Yi Song, Sarath Puthenthermadam, Jiahui Yuan
  • Patent number: 12148459
    Abstract: Technology for read in a cross-point memory array. Drive transistors pass read and write currents to the cross-point memory array. The read current charges a selected word line to turn on a threshold switching selector of a selected memory cell. While the threshold switching selector is on, the current (read or write) passes through the selected memory cell. The memory system applies a smaller overdrive voltage to a drive transistor when the drive transistor is passing the read current than when the drive transistor is passing the write current. A smaller overdrive voltage increases the resistance of the drive transistor. Increasing the resistance of the drive transistor increases the resistance seen by the threshold switching selector in the selected memory cell, which reduces the Ihold of the threshold switching selector.
    Type: Grant
    Filed: February 22, 2022
    Date of Patent: November 19, 2024
    Assignee: SanDisk Technologies LLC
    Inventors: Ward Parkinson, James O'Toole, Thomas Trent, Nathan Franklin, Michael Grobis, James W. Reiner, Hans Jurgen Richter, Michael Nicolas Albert Tran
  • Patent number: 12142323
    Abstract: A memory apparatus and method of operation are provided. The apparatus includes drain-side select gate transistors for coupling to a drain-side of memory holes of memory cells and configured to retain a transistor threshold voltage. The memory holes are arranged in rows comprising strings. A control means is configured to program drain-side select gate transistors of the memory holes to an initial transistor threshold voltage using pulses increasing in magnitude by a first transistor step amount during each of a plurality of foggy loops of a foggy program operation. The control means is also configured to program the drain-side select gate transistors of the memory holes to a target transistor threshold voltage using pulses increasing in magnitude by a second transistor step amount during each of a plurality of fine loops of a fine program operation. The first transistor step amount is greater than the second transistor step amount.
    Type: Grant
    Filed: September 1, 2022
    Date of Patent: November 12, 2024
    Assignee: SanDisk Technologies LLC
    Inventors: Xiaoyu Che, Yanjie Wang
  • Patent number: 12135542
    Abstract: To provide more test data during the manufacture of non-volatile memories and other integrated circuits, machine learning is used to generate virtual test values. Virtual test results are interpolated for one set of tests for devices on which the test is not performed based on correlations with other sets of tests. In one example, machine learning determines a correlation study between bad block values determined at die sort and photo-limited yield (PLY) values determined inline during processing. The correlation can be applied to interpolate virtual inline PLY data for all of the memory dies, allowing for more rapid feedback on the processing parameters for manufacturing the memory dies and making the manufacturing process more efficient and accurate. In another set of embodiments, the machine learning is used to extrapolate limited metrology (e.g., critical dimension) test data to all of the memory die through interpolated virtual metrology data values.
    Type: Grant
    Filed: November 2, 2022
    Date of Patent: November 5, 2024
    Assignee: SanDisk Technologies LLC
    Inventors: Tsuyoshi Sendoda, Yusuke Ikawa, Nagarjuna Asam, Kei Samura, Masaaki Higashitani
  • Patent number: 12137565
    Abstract: A three-dimensional memory device includes an alternating stack of insulating layers and electrically conductive layers, memory openings vertically extending through the alternating stack, and memory opening fill structures located within the memory openings. Each of the electrically conductive layers includes a metallic fill material layer and a plurality of vertical tubular metallic liners laterally surrounding a respective one of the memory opening fill structures and located between the metallic fill material layer and a respective one of the memory opening fill structures. The tubular metallic liners may be formed by selective metal or metal oxide deposition, or by conversion of surface portions of the metallic fill material layers into metallic compound material portions by nitridation, oxidation, or incorporation of boron atoms.
    Type: Grant
    Filed: June 11, 2021
    Date of Patent: November 5, 2024
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Rahul Sharangpani, Raghuveer S. Makala, Fei Zhou, Adarsh Rajashekhar
  • Patent number: 12137554
    Abstract: A three-dimensional memory device includes an alternating stack of insulating layers and electrically conductive layers located over a substrate, memory stack structures vertically extending through the alternating stack, etch stop plates located in the staircase region, laterally and vertically spaced apart among one another, and overlying an end portion of a respective one of the electrically conductive layers, and contact via structures located in a staircase region, vertically extending through a respective one of the etch stop plates, and contacting a respective one of the electrically conductive layers.
    Type: Grant
    Filed: November 12, 2021
    Date of Patent: November 5, 2024
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Adarsh Rajashekhar, Raghuveer S. Makala, Fei Zhou
  • Publication number: 20240364338
    Abstract: On memory die and other circuits, some parts may operate at a VDD logic level while other elements operate at a higher logic level, such as at or near the die's supply level VSUP. To reduce power consumption and increase operating speeds, VDD levels are moving to increasingly lower voltages. To raise the logic signal from the lower level to the higher, level shifters can be used. However, as the gap between the supply level VSUP and VDD widens, it can become difficult for a level shifter to reliably raise a logic signal operating at the VDD level to the VSUP level. The address this problem, the following introduces a small charge pump to boost the input logic signals for level shifter circuits to allow them to reliably generate an output logic signal at the VSUP level from an input logic signal at low VDD levels.
    Type: Application
    Filed: July 3, 2023
    Publication date: October 31, 2024
    Applicant: SanDisk Technologies LLC
    Inventors: Alvin Joshua, Hardwell Chibvongodze, Yuki Kuniyoshi, Akitomo Nakayama
  • Patent number: 12133388
    Abstract: A memory device includes a lower source-level semiconductor layer, a source contact layer, an upper source-level semiconductor layer, and an alternating stack of insulating layers and electrically conductive layers, and a memory opening fill structure vertically extending through the alternating stack and down to an upper portion of the lower source-level semiconductor layer. The memory opening fill structure includes a vertical semiconductor channel, a memory film laterally surrounding the vertical semiconductor channel, and an annular semiconductor cap contacting a bottom surface of the memory film and contacting a top surface segment of the source contact layer. The annular semiconductor cap may be employed as an etch stop structure during a manufacturing process.
    Type: Grant
    Filed: January 25, 2022
    Date of Patent: October 29, 2024
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Kota Funayama, Satoshi Shimizu, Koichi Matsuno
  • Patent number: 12133382
    Abstract: An alternating stack of insulating layers and sacrificial material layers is formed over a substrate, and support pillar structures are formed through the alternating stack. Stepped surfaces are formed by patterning the alternating stack and the support pillar structures. A retro-stepped dielectric material portion is formed over the stepped surfaces. Memory openings and memory opening fill structures are formed through the alternating stack. Electrically conductive layers are formed by replacing at least the sacrificial material layers with at least one electrically conductive material. Contact via structures are formed through the retro-stepped dielectric material portion on the electrically conductive layers. A first support pillar structure is located directly below a first contact via structure.
    Type: Grant
    Filed: February 23, 2022
    Date of Patent: October 29, 2024
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventor: Xiang Yin
  • Publication number: 20240355400
    Abstract: To reduce spikes in the current used during read operations by a system of multiple NAND memory dies operated in parallel, relative delays between the memory dies are introduced before high current sub-operations of the read. The occurrence of the primary current peak in the read operation can depend upon the extent to which a selected memory block is programmed. For example, in a closed block the primary peak occurs when ramping up unselected word lines, while for an open block the primary read peak occurs when the bit lines are charged up. To account for these differences, determining where to introduce relative delays is based on the extent to which a block is programmed. For example, if a block fully or largely closed, delays are introduced before ramping up the unselected word lines, but otherwise adding the delays before charging up bit lines.
    Type: Application
    Filed: July 3, 2023
    Publication date: October 24, 2024
    Applicant: SanDisk Technologies LLC
    Inventors: Abu Naser Zainuddin, Mark Shlick, Jiahui Yuan
  • Publication number: 20240355401
    Abstract: To improve programming performance in NAND memory, while maintaining programming accuracy and reducing program disturb, the channel pre-charge phase before a programming pulse can be eliminated. Instead, a read recovery phase after the program verify directly discharges a selected word line from the verify voltage to a negative word line voltage, with non-selected word lines being directly discharged from the read bypass voltage to the negative word line voltage. From the negative word line voltage, the word lines are then ramped up to ground and then on the bias levels of the following programming pulse. These conditions can drive electrons from the charge storage region of the selected memory cell, resulting in a high degree of channel boosting and much less program disturb. Variations of the technique can be applied to NAND memory operable in a sub-block mode where it can be difficult to use the typical channel pre-charge.
    Type: Application
    Filed: July 3, 2023
    Publication date: October 24, 2024
    Applicant: SanDisk Technologies LLC
    Inventors: Wei Cao, Xiang Yang, Peng Zhang
  • Patent number: 12127406
    Abstract: A semiconductor structure includes an alternating stack of insulating layers and composite layers. Each of the composite layers includes a plurality of electrically conductive word line strips laterally extending along a first horizontal direction and a plurality of dielectric isolation strips laterally extending along the first horizontal direction and interlaced with the plurality of electrically conductive word line strips. Rows of memory openings are arranged along the first horizontal direction. Each row of memory openings vertically extends through each insulating layer within the alternating stack and one electrically conductive strip for each of the composite layers. Rows of memory opening fill structures are located within the rows of memory openings. Each of the memory opening fill structures includes a respective vertical stack of memory elements and a respective vertical semiconductor channel.
    Type: Grant
    Filed: January 18, 2022
    Date of Patent: October 22, 2024
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Takaaki Iwai, Takashi Inomata, Takayuki Maekura
  • Patent number: 12125814
    Abstract: A bonded assembly of a primary semiconductor die and a complementary semiconductor die includes first pairs of first primary bonding pads and first complementary bonding pads that are larger in area than the first primary bonding pads, and second pairs of second primary bonding pads and second complementary bonding pads that are smaller in area than the second primary bonding pads.
    Type: Grant
    Filed: February 8, 2022
    Date of Patent: October 22, 2024
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Lin Hou, Peter Rabkin, Masaaki Higashitani
  • Patent number: 12124247
    Abstract: Techniques are presented for the application of neural networks to the fabrication of integrated circuits and electronic devices, where example are given for the fabrication of non-volatile memory circuits and the mounting of circuit components on the printed circuit board of a solid state drive (SSD). The techniques include the generation of high precision masks suitable for analyzing electron microscope images of feature of integrated circuits and of handling the training of the neural network when the available training data set is sparse through use of a generative adversary network (GAN).
    Type: Grant
    Filed: September 2, 2021
    Date of Patent: October 22, 2024
    Assignee: SanDisk Technologies LLC
    Inventors: Fei Zhou, Cheng-Chung Chu, Raghuveer Makala
  • Patent number: 12127410
    Abstract: A memory device includes a ferroelectric semiconductor channel, a source region contacting a first portion of the ferroelectric semiconductor channel, a drain region located above the source region and contacting a second portion of the ferroelectric semiconductor channel located above the first portion, a word line, and a gate dielectric located between the word line and the ferroelectric semiconductor channel.
    Type: Grant
    Filed: July 13, 2021
    Date of Patent: October 22, 2024
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Peter Rabkin, Masaaki Higashitani
  • Patent number: 12112812
    Abstract: Non-volatile memory cells are programmed by pre-charging channels of unselected non-volatile memory cells connected to a selected data word line, boosting the channels of unselected non-volatile memory cells connected to the selected data word line after the pre-charging and applying a program voltage pulse to selected non-volatile memory cells connected to the selected data word line while boosting. The pre-charging includes applying pre-charge voltages to one set of data word lines and dummy word line(s) as well as applying overdrive voltages to another set of data word lines connected to already programmed memory cells. At the end of the pre-charging, the dummy word lines are ramped down to a resting voltage prior to lowering the data word lines to one or more resting voltages.
    Type: Grant
    Filed: August 10, 2022
    Date of Patent: October 8, 2024
    Assignee: SanDisk Technologies LLC
    Inventors: Jiacen Guo, Dengtao Zhao, Xiang Yang
  • Patent number: 12112800
    Abstract: A method for programming a memory array of a non-volatile memory structure, wherein the memory array comprises a population of MLC NAND-type memory cells, and the method comprises: (1) in a first program pulse, programming selected memory cells according to a first programmable state and a second programmable state, and (2) in a second program pulse, programming the selected memory cells according to a third programmable state.
    Type: Grant
    Filed: May 26, 2022
    Date of Patent: October 8, 2024
    Assignee: SanDisk Technologies LLC
    Inventors: Xiang Yang, Deepanshu Dutta, Muhammad Masuduzzaman, Jiacen Guo
  • Publication number: 20240331741
    Abstract: Techniques are presented to reduce sense amplifier noise from parasitic capacitances that can affect the internal transfer of a data value from a data latch to a sensing node. To transfer the data value, the sensing node is pre-charged and the data value used to set the control gate voltage on a transistor in a discharge path for the sensing node. In the discharge path, the transistor is connected in series with a switch, so that when the switch is turned on, the data value on the transistor's control gate will determine whether or not the sensing node discharges. To reduce noise in the process, before the data value is used to bias the discharge path transistor's control gate, a node between the transistor and switch is charged. Additionally, a lower voltage level can be used to turn on the discharge path switch.
    Type: Application
    Filed: July 3, 2023
    Publication date: October 3, 2024
    Applicant: SanDisk Technologies LLC
    Inventors: Iris Lu, Yonggang Wu, Kou Tei, Ohwon Kwon