Patents by Inventor George Samachisa

George Samachisa 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: 20110310655
    Abstract: A memory device in a 3-D read and write memory includes memory cells. Each memory cell includes a resistance-switching memory element (RSME) in series with a steering element. The RSME has first and second resistance-switching layers on either side of a conductive intermediate layer, and first and second electrodes at either end of the RSME. The first and second resistance-switching layers can both have a bipolar or unipolar switching characteristic. In a set or reset operation of the memory cell, an ionic current flows in the resistance-switching layers, contributing to a switching mechanism. An electron flow, which does not contribute to the switching mechanism, is reduced due to scattering by the conductive intermediate layer, to avoid damage to the steering element. Particular materials and combinations of materials for the different layers of the RSME are provided.
    Type: Application
    Filed: June 9, 2011
    Publication date: December 22, 2011
    Inventors: Franz Kreupl, Abhijit Bandyopadhyay, Yung-Tin Chen, Chu-Chen Fu, Wipul Pemsiri Jayasekara, James Kai, Raghuveer S Makala, Peter Rabkin, George Samachisa, Jingyan Zhang
  • Publication number: 20110299314
    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 reversibly change a level of electrical conductance in response to a voltage difference being applied across them. The three-dimensional array includes a two-dimensional array of pillar lines from the substrate through the multiple layers of planes. A first set of pillar lines acts as local bit lines for accessing the memory elements together with an array of word lines on each plane. A second set of pillar lines is connected to the word lines. An array of metal lines on the substrate is switchable connected to the pillar lines to provide access to the first and second sets of pillar lines, thereby to provide access respectively to the bit lines and word lines of the three-dimensional array.
    Type: Application
    Filed: June 1, 2011
    Publication date: December 8, 2011
    Inventors: George Samachisa, Luca Fasoli, Masaaki Higashitani, Roy Edwin Scheuerlein
  • Publication number: 20110297912
    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 reversibly change a level of electrical conductance in response to a voltage difference being applied across them. The three-dimensional array includes a two-dimensional array of pillar lines from the substrate through the multiple layers of planes which together with arrays of word lines on each plane are used to access the memory elements. The memory elements of the multiple layers are formed simultaneously in an orientation parallel to the substrate thereby reducing processing cost. In another aspect, a diode is formed in series with each memory element to reduce current leakage. The diode is incorporated within a pillar line acting as a bit line without taking up additional space.
    Type: Application
    Filed: June 1, 2011
    Publication date: December 8, 2011
    Inventors: George Samachisa, Johann Alsmeier
  • Publication number: 20110299340
    Abstract: A three-dimensional array is especially adapted for memory elements that reversibly change a level of electrical conductance in response to a voltage difference being applied across them. Memory elements are formed across a plurality of planes positioned different distances above a semiconductor substrate. A two-dimensional array of bit lines to which the memory elements of all planes are connected is oriented vertically from the substrate and through the plurality of planes. During sensing, to compensate for word line resistance, a sense amplifier references a stored reference value during sensing of a memory element at a given location of the word line. A layout with a row of sense amplifiers between two memory arrays is provided to facilitate the referencing. A selected memory element is reset without resetting neighboring ones when it is subject to a bias voltage under predetermined conditions.
    Type: Application
    Filed: June 1, 2011
    Publication date: December 8, 2011
    Inventors: George Samachisa, Luca Fasoli, Yan Li, Tianhong Yan
  • Publication number: 20110280076
    Abstract: A non-volatile memory device includes at least one junctionless transistor and a storage region. The junctionless transistor includes a junctionless, heavily doped semiconductor channel having two dimensions less than 100 nm.
    Type: Application
    Filed: August 2, 2010
    Publication date: November 17, 2011
    Applicant: SanDisk Corporation
    Inventors: George Samachisa, Johann Alsmeier, Andrei Mihnea
  • Patent number: 7983065
    Abstract: A three-dimensional array especially adapted for memory elements that reversibly change a level of electrical conductance in response to a voltage difference being applied across them. Memory elements are formed across a plurality of planes positioned different distances above a semiconductor substrate. Bit lines to which the memory elements of all planes are connected are oriented vertically from the substrate and through the plurality of planes.
    Type: Grant
    Filed: April 8, 2009
    Date of Patent: July 19, 2011
    Assignee: Sandisk 3D LLC
    Inventor: George Samachisa
  • Patent number: 7951669
    Abstract: Methods of fabricating a dual control gate non-volatile memory array are described. Parallel strips of floating gate material are formed over the substrate in a first direction but separated from it by a tunnel dielectric. In the gaps between these strips control gate material is formed forming a second set of parallel strips but insulated from both the adjacent floating gate stripes and the substrate. Both sets of strips are isolated in a second direction perpendicular to the first direction forming an array of individual floating gates and control gates. The control gates formed from an individual control gate strip are then interconnected by a conductive wordline such the potential on individual floating gates are controlled by the voltages on two adjacent wordlines. In other variations either the floating gates or the control gates may be recessed into the original substrate.
    Type: Grant
    Filed: April 13, 2006
    Date of Patent: May 31, 2011
    Assignee: SanDisk Corporation
    Inventors: Eliyahou Harari, George Samachisa
  • Publication number: 20110089391
    Abstract: A storage system and method for forming a storage system that uses punch-through diodes as a steering element in series with a reversible resistivity-switching element is described. The punch-through diode allows bipolar operation of a cross-point memory array. The punch-through diode may have a symmetrical non-linear current/voltage relationship. The punch-through diode has a high current at high bias for selected cells and a low leakage current at low bias for unselected cells. Therefore, it is compatible with bipolar switching in cross-point memory arrays having resistive switching elements. The punch-through diode may be a N+/P?/N+ device or a P+/N?/P+ device.
    Type: Application
    Filed: October 20, 2009
    Publication date: April 21, 2011
    Inventors: Andrei Mihnea, Deepak C. Sekar, George Samachisa, Roy Scheuerlein, Li Xiao
  • Patent number: 7858472
    Abstract: An integrated non-volatile memory circuit is formed by first growing a thin dielectric layer on a semiconductor substrate surface, followed by depositing a layer of conductive material such as doped polysilicon on this dielectric layer, the conductive material then being separated into rows and columns of individual floating gates. Cell source and drain diffusions in the substrate are continuously elongated across the rows. Field dielectric deposited between the rows of floating gates provides electrical isolation between the rows. Shallow trenches may be included between rows without interrupting the conductivity of the diffusions along their lengths. A deep dielectric filled trench is formed in the substrate between the array and peripheral circuits as electrical isolation. Various techniques are included that increase the field coupling area between the floating gates and a control gate.
    Type: Grant
    Filed: March 22, 2007
    Date of Patent: December 28, 2010
    Assignee: SanDisk Corporation
    Inventors: Jack H. Yuan, Eliyahou Harari, Yupin K. Fong, George Samachisa
  • Patent number: 7834392
    Abstract: Non-volatile memory cells store a level of charge corresponding to the data being stored in a dielectric material storage element that is sandwiched between a control gate and the semiconductor substrate surface over channel regions of the memory cells. More than two memory states are provided by one of more than two levels of charge being stored in a common region of the dielectric material. More than one such common region may be included in each cell. In one form, two such regions are provided adjacent source and drain diffusions in a cell that also includes a select transistor positioned between them. In another form, NAND arrays of strings of memory cells store charge in regions of a dielectric layer sandwiched between word lines and the semiconductor substrate.
    Type: Grant
    Filed: July 27, 2009
    Date of Patent: November 16, 2010
    Assignee: SanDisk Corporation
    Inventors: Eliyahou Harari, George Samachisa, Jack H. Yuan, Daniel C. Guterman
  • Patent number: 7830698
    Abstract: A nonvolatile memory cell includes a steering element located in series with a storage element. The storage element includes a carbon material and the memory cell includes a rewritable cell having multiple memory levels.
    Type: Grant
    Filed: May 27, 2008
    Date of Patent: November 9, 2010
    Assignee: SanDisk 3D LLC
    Inventors: Xiying Chen, Bing K. Yen, Dat Nguyen, Huiwen Xu, George Samachisa, Tanmay Kumar, Er-Xuan Ping
  • Publication number: 20100259960
    Abstract: A three-dimensional array especially adapted for memory elements that reversibly change a level of electrical conductance in response to a voltage difference being applied across them. Memory elements are formed across a plurality of planes positioned different distances above a semiconductor substrate. Bit lines to which the memory elements of all planes are connected are oriented vertically from the substrate and through the plurality of planes.
    Type: Application
    Filed: April 8, 2009
    Publication date: October 14, 2010
    Inventor: George Samachisa
  • Publication number: 20100259961
    Abstract: A three-dimensional array especially adapted for memory elements that reversibly change a level of electrical conductance in response to a voltage difference being applied across them. Memory elements are formed across a plurality of planes positioned different distances above a semiconductor substrate. A two-dimensional array of bit lines to which the memory elements of all planes are connected is oriented vertically from the substrate and through the plurality of planes. A double-global-bit-line architecture provides a pair of global bit lines for each bit lines for accessing a row of memory elements in parallel. A first one of each pair allows the local bit lines of the row to be sensed while a second one of each pair allows local bit lines in an adjacent row to be set to a definite voltage so as to eliminate leakage currents between adjacent rows of local bit lines.
    Type: Application
    Filed: March 26, 2010
    Publication date: October 14, 2010
    Inventors: Luca Fasoli, George Samachisa
  • Publication number: 20100259962
    Abstract: A three-dimensional array especially adapted for memory elements that reversibly change a level of electrical conductance in response to a voltage difference being applied across them. Memory elements are formed across a plurality of planes positioned different distances above a semiconductor substrate. A two-dimensional array of bit lines to which the memory elements of all planes are connected is oriented vertically from the substrate and through the plurality of planes. A single-sided word line architecture provides a word line exclusively for each row of memory elements instead of sharing one word line between two rows of memory elements thereby avoids linking the memory element across the array across the word lines. While the row of memory elements is also being accessed by a corresponding row of local bit lines, there is no extension of coupling between adjacent rows of local bit lines and therefore leakage currents beyond the word line.
    Type: Application
    Filed: March 26, 2010
    Publication date: October 14, 2010
    Inventors: Tianhong Yan, George Samachisa
  • Publication number: 20090286370
    Abstract: Non-volatile memory cells store a level of charge corresponding to the data being stored in a dielectric material storage element that is sandwiched between a control gate and the semiconductor substrate surface over channel regions of the memory cells. More than two memory states are provided by one of more than two levels of charge being stored in a common region of the dielectric material. More than one such common region may be included in each cell. In one form, two such regions are provided adjacent source and drain diffusions in a cell that also includes a select transistor positioned between them. In another form, NAND arrays of strings of memory cells store charge in regions of a dielectric layer sandwiched between word lines and the semiconductor substrate.
    Type: Application
    Filed: July 27, 2009
    Publication date: November 19, 2009
    Inventors: Eliyahou Harari, George Samachisa, Jack H. Yuan, Daniel C. Guterman
  • Publication number: 20090257265
    Abstract: A nonvolatile memory cell includes a steering element located in series with a storage element. The storage element includes a carbon material and the memory cell includes a rewritable cell having multiple memory levels.
    Type: Application
    Filed: May 27, 2008
    Publication date: October 15, 2009
    Inventors: Xiying Chen, Bing K. Yen, Dat Nguyen, Huiwen Xu, George Samachisa, Tanmay Kumar, Er-Xuan Ping
  • Patent number: 7579247
    Abstract: Non-volatile memory cells store a level of charge corresponding to the data being stored in a dielectric material storage element that is sandwiched between a control gate and the semiconductor substrate surface over channel regions of the memory cells. More than two memory states are provided by one of more than two levels of charge being stored in a common region of the dielectric material. More than one such common region may be included in each cell. In one form, two such regions are provided adjacent source and drain diffusions in a cell that also includes a select transistor positioned between them. In another form, NAND arrays of strings of memory cells store charge in regions of a dielectric layer sandwiched between word lines and the semiconductor substrate.
    Type: Grant
    Filed: January 25, 2008
    Date of Patent: August 25, 2009
    Assignee: SanDisk Corporation
    Inventors: Eliyahou Harari, George Samachisa, Jack H. Yuan, Daniel C. Guterman
  • Patent number: 7491999
    Abstract: Several embodiments of flash EEPROM split-channel cell arrays are described that position the channels of cell select transistors along sidewalls of trenches in the substrate, thereby reducing the cell area. Select transistor gates are formed as part of the word lines and extend downward into the trenches with capacitive coupling between the trench sidewall channel portion and the select gate. In one embodiment, trenches are formed between every other floating gate along a row, the two trench sidewalls providing the select transistor channels for adjacent cells, and a common source/drain diffusion is positioned at the bottom of the trench. A third gate provides either erase or steering capabilities. In another embodiment, trenches are formed between every floating gate along a row, a source/drain diffusion extending along the bottom of the trench and upwards along one side with the opposite side of the trench being the select transistor channel for a cell.
    Type: Grant
    Filed: June 8, 2006
    Date of Patent: February 17, 2009
    Assignee: Sandisk Corporation
    Inventors: Eliyahou Harari, Jack H. Yuan, George Samachisa, Henry Chien
  • Patent number: 7479677
    Abstract: Non-volatile memory cells store a level of charge corresponding to the data being stored in a dielectric material storage element that is sandwiched between a control gate and the semiconductor substrate surface over channel regions of the memory cells. More than two memory states are provided by one of more than two levels of charge being stored in a common region of the dielectric material. More than one such common region may be included in each cell. In one form, two such regions are provided adjacent source and drain diffusions in a cell that also includes a select transistor positioned between them. In another form, NAND arrays of strings of memory cells store charge in regions of a dielectric layer sandwiched between word lines and the semiconductor substrate.
    Type: Grant
    Filed: January 25, 2008
    Date of Patent: January 20, 2009
    Assignee: Sandisk Corporation
    Inventors: Eliyahou Harari, George Samachisa, Jack H. Yuan, Daniel C. Guterman
  • Patent number: 7468915
    Abstract: In a non-volatile memory, the displacement current generated in non-selected word lines that results when the voltage levels on an array's bit lines are changed can result in disturbs. Techniques for reducing these currents are presented. In a first aspect, the number of cells being simultaneously programmed on a word line is reduced. In a non-volatile memory where an array of memory cells is composed of a number of units, and the units are combined into planes that share common word lines, the simultaneous programming of units within the same plane is avoided. Multiple units may be programmed in parallel, but these are arranged to be in separate planes. This is done by selecting the number of units to be programmed in parallel and their order such that all the units programmed together are from distinct planes, by comparing the units to be programmed to see if any are from the same plane, or a combination of these.
    Type: Grant
    Filed: October 4, 2006
    Date of Patent: December 23, 2008
    Assignee: SanDisk Corporation
    Inventors: Daniel C. Guterman, George Samachisa, Brian Murphy, Chi-Ming Wang, Khandker N. Quader