Patents by Inventor Tianhong Yan

Tianhong Yan 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).

  • 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: 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: 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: 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
  • 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: 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
  • Patent number: 9240235
    Abstract: A method includes adjusting a counter value to indicate an access operation to a first portion of a non-volatile memory. The access operation is an erase operation or a write operation. The adjusted counter value indicates that a number of access operations to the first portion have been performed since an access operation to a second portion of the non-volatile memory has been performed. The method also includes selectively initiating a remedial action to the second portion in response to a comparison of the number of access operations to a threshold.
    Type: Grant
    Filed: December 19, 2013
    Date of Patent: January 19, 2016
    Assignee: SANDISK TECHNOLOGIES INC.
    Inventors: Idan Alrod, Eran Sharon, Tz-Yi Liu, Tianhong Yan, Menahem Lasser
  • 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: 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: 9196362
    Abstract: Methods for forming non-volatile storage elements in a non-volatile storage system are described. In some embodiments, during a forming operation, a cross-point memory array may be biased such that waste currents are minimized or eliminated. In one example, the memory array may be biased such that a first word line comb is set to a first voltage, a second word line comb interdigitated with the first word line comb is set to the first voltage, and selected vertical bit lines are set to a second voltage such that a forming voltage is applied across non-volatile storage elements to be formed. In some embodiments, a memory array may include a plurality of word line comb layers and a forming operation may be concurrently performed on non-volatile storage elements on all of the plurality of word line comb layers or a subset of the plurality of word line comb layers.
    Type: Grant
    Filed: April 5, 2014
    Date of Patent: November 24, 2015
    Assignee: SANDISK 3D LLC
    Inventors: Chang Siau, Tianhong Yan
  • Patent number: 9165649
    Abstract: A method of shaping data includes receiving data represented as a first set of bits, where each bit of the first set of bits corresponds to a logical value. A first write current to write a first logical value to a storage element is less than a second write current to write a second logical value to the storage element. The method also includes applying a shaping operation to generate a second set of bits, where a proportion of bits having the first logical value is larger for the second set of bits than for the first set of bits. The method also includes writing the second set of bits to the memory.
    Type: Grant
    Filed: December 20, 2013
    Date of Patent: October 20, 2015
    Assignee: SANDISK TECHNOLOGIES INC.
    Inventors: Eran Sharon, Tz-Yi Liu, Tianhong Yan, Idan Alrod
  • Publication number: 20150287459
    Abstract: A programming technique for a set of resistance-switching memory cells such as ReRAM cell involves programming the low resistance cells to the high resistance state (in a reset process) early in a programming operation, before programming the high resistance cells to the low resistance state (in a set process), to minimize losses due to leakage currents. The reset process can be performed in one or more phases. In some cases, a current limit is imposed which limits the number of cells which can be reset at the same time. Initially, the cells which are to be reset and set are identified by comparing a logical value of their current resistance state to a logical value of write data. If there is a match, the cell is not programmed. If there is not a match, the cell is programmed.
    Type: Application
    Filed: April 4, 2014
    Publication date: October 8, 2015
    Applicant: SanDisk Technologies Inc.
    Inventors: Ariel Navon, Idan Alrod, Eran Sharon, Ishai Ilani, Tz-yi Liu, Tianhong Yan, Gopinath Balakrishnan
  • Publication number: 20150269998
    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: Application
    Filed: June 7, 2015
    Publication date: September 24, 2015
    Inventors: Chang Siau, Tianhong Yan
  • Patent number: 9123392
    Abstract: A three-dimensional array of memory elements is formed across multiple layers of planes positioned at different distances above a semiconductor substrate. The memory elements are each accessible by a word line in a plane and a local bit line. The three-dimensional array includes a two-dimensional array of pillar lines through the multiple layers of planes. The pillar lines are of a first type that act as local bit lines and a second type that provide access to the word lines by having respective memory elements preset to a permanently low resistance state for connecting second-type pillar lines for exclusive access to respective word lines. An array of metal lines on the substrate is switchably connected to the vertical bit lines to provide access to the local bit lines and the word lines.
    Type: Grant
    Filed: March 28, 2014
    Date of Patent: September 1, 2015
    Assignee: SANDISK 3D LLC
    Inventors: Tianhong Yan, Roy Edwin Scheuerlein
  • Publication number: 20150179260
    Abstract: A method of shaping data includes receiving data represented as a first set of bits, where each bit of the first set of bits corresponds to a logical value. A first write current to write a first logical value to a storage element is less than a second write current to write a second logical value to the storage element. The method also includes applying a shaping operation to generate a second set of bits, where a proportion of bits having the first logical value is larger for the second set of bits than for the first set of bits. The method also includes writing the second set of bits to the memory.
    Type: Application
    Filed: December 20, 2013
    Publication date: June 25, 2015
    Applicant: SANDISK TECHNOLOGIES INC.
    Inventors: ERAN SHARON, TZ-YI LIU, TIANHONG YAN, IDAN ALROD
  • Publication number: 20150179254
    Abstract: A method includes adjusting a counter value to indicate an access operation to a first portion of a non-volatile memory. The access operation is an erase operation or a write operation. The adjusted counter value indicates that a number of access operations to the first portion have been performed since an access operation to a second portion of the non-volatile memory has been performed. The method also includes selectively initiating a remedial action to the second portion in response to a comparison of the number of access operations to a threshold.
    Type: Application
    Filed: December 19, 2013
    Publication date: June 25, 2015
    Applicant: SANDISK TECHNOLOGIES INC.
    Inventors: IDAN ALROD, ERAN SHARON, TZ-YI LIU, TIANHONG YAN, MENAHEM LASSER
  • Patent number: 9053766
    Abstract: A three dimensional monolithic memory array of non-volatile storage elements includes a plurality of word lines and a plurality of bit lines. The plurality of bit lines are grouped into columns. Performing memory operation on the non-volatile storage elements includes selectively connecting bit lines to sense amplifiers using selection circuits that include a storage device, a select circuit connected to the storage device and one or more level shifters providing two or more interfaces to the respective selection circuit.
    Type: Grant
    Filed: March 3, 2011
    Date of Patent: June 9, 2015
    Assignee: SANDISK 3D, LLC
    Inventor: Tianhong Yan
  • Patent number: 8982597
    Abstract: The system includes multiple sets of local data lines in one or more routing metal layers below the three-dimensional memory array and multiple sets of global data lines in one or more top metal layers above the three-dimensional memory array. Each set of one or more blocks include one set of the local data lines. Each bay includes one set of global data lines that connect to the group of sense amplifiers associated with the blocks of the respective bay. Each block includes a subset of first selection circuits for selectively coupling a subset of array lines of the first type to respective local data lines. Each block includes a subset of second selection circuits for selectively coupling a subset of the respective local data lines to global data lines associated with a respective bay.
    Type: Grant
    Filed: January 31, 2012
    Date of Patent: March 17, 2015
    Assignee: Sandisk 3D LLC
    Inventors: Tianhong Yan, Luca Fasoli
  • Publication number: 20150036414
    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: Application
    Filed: July 24, 2014
    Publication date: February 5, 2015
    Inventors: Tianhong Yan, George Samachisa, Tz-yi Liu, Tim Chen, Perumal Ratnam
  • Patent number: 8913413
    Abstract: The system includes multiple sets of local data lines in one or more routing metal layers below the three-dimensional memory array and multiple sets of global data lines in one or more top metal layers above the three-dimensional memory array. Each set of one or more blocks include one set of the local data lines. Each bay includes one set of global data lines that connect to the group of sense amplifiers associated with the blocks of the respective bay. Each block includes a subset of first selection circuits for selectively coupling a subset of array lines of the first type to respective local data lines. Each block includes a subset of second selection circuits for selectively coupling a subset of the respective local data lines to global data lines associated with a respective bay.
    Type: Grant
    Filed: January 31, 2012
    Date of Patent: December 16, 2014
    Assignee: SanDisk 3D LLC
    Inventors: Tianhong Yan, Luca Fasoli