Patents Assigned to Sandisk 3D LLC
  • Publication number: 20160019952
    Abstract: Methods for reducing leakage currents through unselected memory cells of a memory array during a memory operation are described. In some cases, the leakage currents through the unselected memory cells of the memory array may be reduced by setting an adjustable resistance bit line structure connected to the unselected memory cells into a non-conducting state. The adjustable resistance bit line structure may comprise a bit line structure in which the resistance of an intrinsic (or near intrinsic) polysilicon portion of the bit line structure may be adjusted via an application of a voltage to a select gate portion of the bit line structure that is not directly connected to the intrinsic polysilicon portion. The intrinsic polysilicon portion may be set into a conducting state or a non-conducting state based on the voltage applied to the select gate portion.
    Type: Application
    Filed: May 18, 2015
    Publication date: January 21, 2016
    Applicant: SANDISK 3D LLC
    Inventor: Perumal Ratnam
  • Publication number: 20160019963
    Abstract: Methods for reducing leakage currents through unselected memory cells of a memory array during a memory operation are described. In some cases, the leakage currents through the unselected memory cells of the memory array may be reduced by setting an adjustable resistance bit line structure connected to the unselected memory cells into a non-conducting state. The adjustable resistance bit line structure may comprise a bit line structure in which the resistance of an intrinsic (or near intrinsic) polysilicon portion of the bit line structure may be adjusted via an application of a voltage to a select gate portion of the bit line structure that is not directly connected to the intrinsic polysilicon portion. The intrinsic polysilicon portion may be set into a conducting state or a non-conducting state based on the voltage applied to the select gate portion.
    Type: Application
    Filed: May 19, 2015
    Publication date: January 21, 2016
    Applicant: SANDISK 3D LLC
    Inventor: Tianhong Yan
  • Publication number: 20160019957
    Abstract: Methods for reducing leakage currents through unselected memory cells of a memory array during a memory operation are described. In some cases, the leakage currents through the unselected memory cells of the memory array may be reduced by setting an adjustable resistance bit line structure connected to the unselected memory cells into a non-conducting state. The adjustable resistance bit line structure may comprise a bit line structure in which the resistance of an intrinsic (or near intrinsic) polysilicon portion of the bit line structure may be adjusted via an application of a voltage to a select gate portion of the bit line structure that is not directly connected to the intrinsic polysilicon portion. The intrinsic polysilicon portion may be set into a conducting state or a non-conducting state based on the voltage applied to the select gate portion.
    Type: Application
    Filed: May 18, 2015
    Publication date: January 21, 2016
    Applicant: SANDISK 3D LLC
    Inventors: Perumal Ratnam, Christopher Petti, Tianhong Yan
  • Publication number: 20160020389
    Abstract: Methods for reducing leakage currents through unselected memory cells of a memory array during a memory operation are described. In some cases, the leakage currents through the unselected memory cells of the memory array may be reduced by setting an adjustable resistance bit line structure connected to the unselected memory cells into a non-conducting state. The adjustable resistance bit line structure may comprise a bit line structure in which the resistance of an intrinsic (or near intrinsic) polysilicon portion of the bit line structure may be adjusted via an application of a voltage to a select gate portion of the bit line structure that is not directly connected to the intrinsic polysilicon portion. The intrinsic polysilicon portion may be set into a conducting state or a non-conducting state based on the voltage applied to the select gate portion.
    Type: Application
    Filed: May 19, 2015
    Publication date: January 21, 2016
    Applicant: SANDISK 3D LLC
    Inventors: Perumal Ratnam, Christopher Petti, Tianhong Yan
  • Publication number: 20160019961
    Abstract: Methods for reducing leakage currents through unselected memory cells of a memory array during a memory operation are described. In some cases, the leakage currents through the unselected memory cells of the memory array may be reduced by setting an adjustable resistance bit line structure connected to the unselected memory cells into a non-conducting state. The adjustable resistance bit line structure may comprise a bit line structure in which the resistance of an intrinsic (or near intrinsic) polysilicon portion of the bit line structure may be adjusted via an application of a voltage to a select gate portion of the bit line structure that is not directly connected to the intrinsic polysilicon portion. The intrinsic polysilicon portion may be set into a conducting state or a non-conducting state based on the voltage applied to the select gate portion.
    Type: Application
    Filed: May 18, 2015
    Publication date: January 21, 2016
    Applicant: SANDISK 3D LLC
    Inventors: Perumal Ratnam, Christopher Petti, Tianhong Yan
  • Publication number: 20160019953
    Abstract: Methods for reducing leakage currents through unselected memory cells of a memory array during a memory operation are described. In some cases, the leakage currents through the unselected memory cells of the memory array may be reduced by setting an adjustable resistance bit line structure connected to the unselected memory cells into a non-conducting state. The adjustable resistance bit line structure may comprise a bit line structure in which the resistance of an intrinsic (or near intrinsic) polysilicon portion of the bit line structure may be adjusted via an application of a voltage to a select gate portion of the bit line structure that is not directly connected to the intrinsic polysilicon portion. The intrinsic polysilicon portion may be set into a conducting state or a non-conducting state based on the voltage applied to the select gate portion.
    Type: Application
    Filed: May 18, 2015
    Publication date: January 21, 2016
    Applicant: SANDISK 3D LLC
    Inventors: Perumal Ratnam, Christopher Petti, Tianhong Yan
  • Publication number: 20160019960
    Abstract: Methods for reducing leakage currents through unselected memory cells of a memory array during a memory operation are described. In some cases, the leakage currents through the unselected memory cells of the memory array may be reduced by setting an adjustable resistance bit line structure connected to the unselected memory cells into a non-conducting state. The adjustable resistance bit line structure may comprise a bit line structure in which the resistance of an intrinsic (or near intrinsic) polysilicon portion of the bit line structure may be adjusted via an application of a voltage to a select gate portion of the bit line structure that is not directly connected to the intrinsic polysilicon portion. The intrinsic polysilicon portion may be set into a conducting state or a non-conducting state based on the voltage applied to the select gate portion.
    Type: Application
    Filed: May 18, 2015
    Publication date: January 21, 2016
    Applicant: SANDISK 3D LLC
    Inventors: Perumal Ratnam, Christopher Petti, Tianhong Yan
  • Publication number: 20160020255
    Abstract: Methods for reducing leakage currents through unselected memory cells of a memory array during a memory operation are described. In some cases, the leakage currents through the unselected memory cells of the memory array may be reduced by setting an adjustable resistance bit line structure connected to the unselected memory cells into a non-conducting state. The adjustable resistance bit line structure may comprise a bit line structure in which the resistance of an intrinsic (or near intrinsic) polysilicon portion of the bit line structure may be adjusted via an application of a voltage to a select gate portion of the bit line structure that is not directly connected to the intrinsic polysilicon portion. The intrinsic polysilicon portion may be set into a conducting state or a non-conducting state based on the voltage applied to the select gate portion.
    Type: Application
    Filed: May 18, 2015
    Publication date: January 21, 2016
    Applicant: SANDISK 3D LLC
    Inventors: Perumal Ratnam, Christopher Petti, Tianhong Yan
  • Patent number: 9236122
    Abstract: A non-volatile storage device comprises: a substrate; a monolithic three dimensional array of memory cells; word lines connected to the memory cells; global bit lines; vertical bit lines connected to the memory cells; and a plurality of double gated vertically oriented select devices. The double gated vertically oriented select devices are connected to the vertical bit lines and the global bit lines so that when the double gated vertically oriented select devices are activated the vertical bit lines are in communication with the global bit lines. Each double gated vertically oriented select device has two gates that are offset from each other with respect to distance to the substrate. Both gates for the double gated vertically oriented select device need be in an “on” condition for the double gated vertically oriented select devices to be activated.
    Type: Grant
    Filed: July 24, 2014
    Date of Patent: January 12, 2016
    Assignee: SANDISK 3D LLC
    Inventors: Tianhong Yan, George Samachisa, Tz-yi Liu, Tim Chen, Perumal Ratnam
  • Patent number: 9227456
    Abstract: A three-dimensional memory is formed as an array of memory elements across multiple layers positioned at different distances above a semiconductor substrate. Cylindrical stacks of memory elements are formed where a cylindrical opening has read/write material deposited along its wall, and a cylindrical vertical bit line formed along its central axis. Memory elements formed on either side of such a cylinder may include sheet electrodes that extend into the read/write material.
    Type: Grant
    Filed: March 7, 2013
    Date of Patent: January 5, 2016
    Assignee: SanDisk 3D LLC
    Inventors: Henry Chien, Yao-Sheng Lee, George Samachisa, Johann Alsmeier
  • Patent number: 9230905
    Abstract: A multilevel device includes: at least one device region and at least one contact region having a stack of alternating plurality of continuous electrically conductive layers and plurality of electrically insulating layers located over a base. Each electrically conductive layer in the stack is electrically insulated from the other electrically conductive layers in the stack. The base may include a raised portion and a plurality of recesses in the raised portion, each recess in the plurality of recesses having a different lateral size from the other recesses in the plurality of recesses. The electrically conductive layers in the stack may be substantially conformal to the plurality of recesses in the base and expose one or more top surfaces of the raised portion of the base. A first electrically conductive layer in the stack may be a topmost layer in a laterally central portion of a first one of the plurality of recesses.
    Type: Grant
    Filed: January 8, 2014
    Date of Patent: January 5, 2016
    Assignee: SANDISK 3D LLC
    Inventors: Seje Takaki, Michiaki Sano, Zhen Chen
  • Patent number: 9230985
    Abstract: A vertically oriented thin film transistor (TFT) having a tunnel barrier is disclosed. The tunnel barrier may be formed from a dielectric such as silicon oxide or hafnium oxide. The vertically oriented TFT selection device with tunnel barrier may serve as a selection device in a 3D memory array. The vertically oriented TFT may be used to connect/disconnect a global bit line to/from a vertical bit line in a 3D memory array. The vertically oriented TFT may be used to connect/disconnect a source line to/from a channel of a vertical NAND string in a 3D memory array. A vertical TFT with tunnel barrier has a high breakdown voltage, low leakage current, and high on current. The tunnel barrier can be at the top junction or bottom junction of the TFT.
    Type: Grant
    Filed: October 15, 2014
    Date of Patent: January 5, 2016
    Assignee: SanDisk 3D LLC
    Inventors: Ming-Che Wu, Peter Rabkin, Tim Chen
  • Patent number: 9224466
    Abstract: Methods and apparatus are provided for reading a selected memory cell of a memory array using a sense amplifier that includes a first capacitor and a second capacitor. The selected memory cell is coupled to a bit line and a selected word line. A first noise voltage is generated on the first capacitor, and a selected memory cell voltage and a second noise voltage are generated on the second capacitor. The first noise voltage is an estimate of the second noise voltage. An output signal value is generated proportional to a difference between the selected memory cell voltage and a reference voltage, and a difference between the first noise voltage and second noise voltage. The output signal value is used to determine a data value for the selected memory cell.
    Type: Grant
    Filed: September 29, 2014
    Date of Patent: December 29, 2015
    Assignee: SanDisk 3D LLC
    Inventors: Yingchang Chen, Anurag Nigam
  • Patent number: 9224951
    Abstract: A resistive-switching memory (ReRAM cell) has a current-limiting electrode layer that combines the functions of an embedded resistor, an outer electrode, and an intermediate electrode, reducing the thickness of the ReRAM stack and simplifying the fabrication process. The materials include compound nitrides of a transition metal and one of aluminum, boron, or silicon. In experiments with tantalum silicon nitride, peak yield in the desired resistivity range corresponded to ˜24 at % silicon and ˜32 at % nitrogen, believed to optimize the trade-off between inhibiting TaSi2 formation and minimizing nitrogen diffusion. A binary metal nitride may be formed at one or more of the interfaces between the current-limiting electrode and neighboring layers such as metal-oxide switching layers.
    Type: Grant
    Filed: July 21, 2014
    Date of Patent: December 29, 2015
    Assignees: Intermolecular, Inc., Kabushiki Kaisha Toshiba, SanDisk 3D LLC
    Inventors: Yun Wang, Federico Nardi, Milind Weling
  • Patent number: 9225304
    Abstract: A single-stage folded cascode buffer including an amplifier, a first analog comparator, a second analog comparator, a first transistor, and a second transistor, The amplifier includes a first input terminal, a second input terminal, and an output terminal coupled to the second input terminal of the amplifier. The first analog comparator includes a first input terminal, a second input terminal, and an output terminal. The second analog comparator includes a first input terminal, a second input terminal, and an output terminal. The first transistor includes a first terminal, a second terminal coupled to the output terminal of the first analog comparator, and a third terminal coupled to the output terminal of the amplifier. The second transistor includes a first terminal coupled to the output terminal of the amplifier, a second terminal coupled to the output terminal of the second analog comparator, and a third terminal.
    Type: Grant
    Filed: October 24, 2014
    Date of Patent: December 29, 2015
    Assignee: SanDisk 3D LLC
    Inventor: Vincent Lai
  • Patent number: 9214243
    Abstract: A three-dimensional memory is provided that includes a first memory level and a second memory level monolithically formed above the first memory level. The first memory level includes a first steering element coupled in series with and vertically stacked above or below a first non-volatile state change element. The second memory level includes a second steering element coupled in series with and vertically stacked above or below a second non-volatile state change element. Other aspects are also provided.
    Type: Grant
    Filed: May 6, 2014
    Date of Patent: December 15, 2015
    Assignee: SanDisk 3D LLC
    Inventors: Mark G. Johnson, Thomas H. Lee, Vivek Subramanian, Paul Michael Farmwald, James M. Cleeves
  • Patent number: 9208873
    Abstract: Methods for reducing power consumption of a non-volatile storage system and reducing first read latency are described. The non-volatile storage system may include a cross-point memory array. In some embodiments, during a standby mode, the memory array may be biased such that both word lines and bit lines are set to ground. During transition of the memory array from the standby mode to a read mode, a selected word line comb may be set to a read voltage while the unselected word lines and the bit lines remain at ground. During the read mode, memory cells connected to the selected bit lines and the selected word line comb may be sensed while the selected bit lines are biased to a selected bit line voltage equal to or close to ground and the unselected bit lines are left floating after initially being set to ground.
    Type: Grant
    Filed: April 29, 2015
    Date of Patent: December 8, 2015
    Assignee: SANDISK 3D LLC
    Inventor: Chang Siau
  • Patent number: 9202694
    Abstract: Three-dimensional (3D) non-volatile memory arrays having a vertically-oriented thin film transistor (TFT) select device and methods 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. The gates overlie the global bit lines with one or more insulating layers therebetween to provide adequate isolation between the gates and the global bit lines. Processes for fabricating the vertical TFT select devices utilize a gate dielectric and optional dielectric bases to provide isolation between the gates and bit lines.
    Type: Grant
    Filed: March 4, 2014
    Date of Patent: December 1, 2015
    Assignee: SanDisk 3D LLC
    Inventors: Michael Konevecki, Steve Radigan, Vance Dunton, Natalie Nguyen, Luke Zhang
  • Patent number: 9202566
    Abstract: Methods for forming non-volatile storage elements in a non-volatile storage system are described. In some embodiments, a plurality of forming operations may be performed in which non-volatile storage elements located near the far end of a plurality of word line fingers associated with a word line comb are formed prior to forming other non-volatile storage elements. In one example, non-volatile storage elements may be formed in each of the plurality of word line fingers in parallel and in an order that forms non-volatile storage elements in each of the plurality of word line fingers that are located near the far ends of the plurality of word line fingers before forming other non-volatile storage elements. Each non-volatile storage element that is formed during a forming operation may be current limited while a forming voltage is applied across the non-volatile storage element.
    Type: Grant
    Filed: April 5, 2014
    Date of Patent: December 1, 2015
    Assignee: SANDISK 3D LLC
    Inventors: Chang Siau, Tianhong Yan
  • Patent number: 9202539
    Abstract: A method is provided for programming a memory cell having a first terminal coupled to a word line and a second terminal coupled to a bit line. During a first predetermined time interval, the word line is switched from a first standby voltage to a first voltage, the bit line is switched from a second standby voltage to a predetermined voltage, and a voltage drop across the first and second terminals is a safe voltage that does not program the memory cell. During a second predetermined time interval, the word line is switched from the first voltage to a second voltage, and a voltage drop across the first and second terminals is a programming voltage that is sufficient to program the memory cell. Numerous other aspects are provided.
    Type: Grant
    Filed: May 29, 2014
    Date of Patent: December 1, 2015
    Assignee: SanDisk 3D LLC
    Inventors: Tyler J. Thorp, Roy E. Scheuerlein