Patents Assigned to Sandisk 3D LLC
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Patent number: 7221588Abstract: An exemplary NAND string memory array includes at least one plane of memory cells, said memory cells comprising thin film modifiable conductance switch devices and which cells are arranged in a plurality of series-connected NAND strings, and NAND strings including a series select device at each end thereof. Another exemplary NAND string memory array includes a group of more than four adjacent NAND strings within the same memory block each associated with a respective global bit line not shared by the other NAND string of the group. Another exemplary NAND string memory array includes NAND strings on identical pitch as their respective global bit lines.Type: GrantFiled: December 5, 2003Date of Patent: May 22, 2007Assignee: Sandisk 3D LLCInventors: Luca G. Fasoli, Roy E. Scheuerlein, En-Hsing Chen, Sucheta Nallamothu, Maitreyee Mahajani, Andrew J. Walker
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Patent number: 7218570Abstract: An apparatus is disclosed comprising a plurality of word lines and word line drivers, a plurality of bit lines and bit line drivers, and a plurality of memory cells coupled between respective word lines and bit lines. The apparatus also comprises circuitry operative to select a writing and/or reading condition to apply to a memory cell based on the memory cell's location with respect to one or both of a word line driver and a bit line driver. The apparatus can also comprise circuitry that is operative to select a number of memory cells to be programmed in parallel based on memory cell location with respect to a word line and/or bit line driver.Type: GrantFiled: December 17, 2004Date of Patent: May 15, 2007Assignee: SanDisk 3D LLCInventors: Kenneth K. So, Luca G. Fasoli, Roy E. Scheuerlein
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Patent number: 7219271Abstract: The preferred embodiments described herein provide a memory device and method for redundancy/self-repair. In one preferred embodiment, a memory device is provided comprising a primary block of memory cells and a redundant block of memory cells. In response to an error in writing to the primary block, a flag is stored in a set of memory cells allocated to the primary block, and the redundant block is written into. In another preferred embodiment, an error in writing to a primary block is detected while an attempt is made to write to that block. In response to the error, the redundant block is written into. In yet another preferred embodiment, a memory device is provided comprising a three-dimensional memory array and redundancy circuitry. In still another preferred embodiment, a method for testing a memory array is provided. Other preferred embodiments are provided, and each of the preferred embodiments described herein can be used alone or in combination with one another.Type: GrantFiled: December 14, 2001Date of Patent: May 15, 2007Assignee: SanDisk 3D LLCInventors: Bendik Kleveland, Alper Ilkbahar, Roy E. Scheuerlein
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Patent number: 7212454Abstract: A method and apparatus for programming a memory array are disclosed. In one embodiment, after each word line is programmed, an attempt is made to detect a defect on that word line. If a defect is detected, the word line is repaired with a redundant word line. The word lines are then reprogrammed and rechecked for defects. In another embodiment, after each word line is programmed, an attempt is made to detect a defect on that word line. If a defect is detected, that word line is repaired along with a previously-programmed adjacent word line. In yet another embodiment, after each word line is programmed, an attempt is made to detect a defect on that word line and a previously-programmed adjacent word line. If a defect is detected on that word line, that word line and the previously-programmed adjacent word line are repaired with redundant word lines.Type: GrantFiled: June 22, 2005Date of Patent: May 1, 2007Assignee: SanDisk 3D LLCInventors: Bendik Kleveland, Tae Hee Lee, Seung Geon Yu, Chia Yang, Feng Li, Xiaoyu Yang
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Patent number: 7203084Abstract: The preferred embodiments described herein provide a memory device and methods for use therewith. In one preferred embodiment, a method is presented for using a file system to dynamically respond to variability in an indicated minimum number of memory cells of first and second write-once memory devices. In another preferred embodiment, a method for overwriting data in a memory device is described in which an error code is disregarded after a destructive pattern is written. In yet another preferred embodiment, a method is presented in which, after a block of memory has been allocated for a file to be stored in a memory device, available lines in that block are determined. Another preferred embodiment relates to reserving at least one memory cell in a memory device for file structures or file system structures. A memory device is also provided in which file system structures of at least two file systems are stored in the same memory partition.Type: GrantFiled: May 6, 2004Date of Patent: April 10, 2007Assignee: SanDisk 3D LLCInventors: Thomas H. Lee, Mark G. Johnson
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Patent number: 7195992Abstract: A method to create a polysilicon layer with large grains and uniform grain density is described. A first amorphous silicon layer is formed. A crystallizing agent is selectively introduced in a substantially symmetric pattern, preferably symmetric in two dimensions, across an area of the first amorphous layer. The crystallizing agent may be, for example, silicon nuclei, germanium, or laser energy. A mask layer is formed on the amorphous silicon layer, and holes etched in the mask layer in a symmetric pattern to expose the amorphous layer to, for example, silicon nuclei or germanium) only in the holes. The mask layer is removed and a second amorphous layer formed on the first. If laser energy is used, no mask layer or second amorphous layer is generally used. The wafer is annealed to form a polysilicon layer with substantially no amorphous silicon remaining between the grains.Type: GrantFiled: October 7, 2003Date of Patent: March 27, 2007Assignee: Sandisk 3D LLCInventors: Shuo Gu, James M. Cleeves
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Patent number: 7190602Abstract: A very high density field programmable memory is disclosed. An array is formed vertically above a substrate using several layers, each layer of which includes vertically fabricated memory cells. The cell in an N level array may be formed with N+1 masking steps plus masking steps needed for contacts. Maximum use of self alignment techniques minimizes photolithographic limitations. In one embodiment the peripheral circuits are formed in a silicon substrate and an N level array is fabricated above the substrate.Type: GrantFiled: February 9, 2004Date of Patent: March 13, 2007Assignee: SanDisk 3D LLCInventors: Mark G. Johnson, Thomas H. Lee, James M. Cleeves
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Patent number: 7177227Abstract: A multi-headed word line driver circuit incorporates bent-gate transistors to reduce the pitch otherwise achievable for interfacing to tightly-pitched array lines. In certain exemplary embodiments, a three-dimensional memory array includes multiple memory blocks and array lines traversing horizontally across at least one memory block. Vertical active area stripes are disposed beneath a first memory block, and a respective plurality of bent-gate electrodes intersects each respective active area stripe to define individual source/drain regions. Every other source/drain region is coupled to a bias node for the active area stripe, and remaining source/drain regions are respectively coupled to a respective array line associated with the first memory block, thereby forming a respective first driver transistor for the respective array line.Type: GrantFiled: May 29, 2006Date of Patent: February 13, 2007Assignee: SanDisk 3D LLCInventors: Christopher J. Petti, Roy E. Scheuerlein, Tanmay Kumar, Abhijit Bandyopadhyay
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Patent number: 7177191Abstract: A monolithic integrated circuit includes a memory array having first and second groups of NAND strings, each NAND string comprising at least two series-connected devices and coupled at one end to an associated global array line. NAND strings of the first and second groups differ in at least one physical characteristic, such as the number of series-connected devices forming the NAND string, but both groups are disposed in a region of the memory array traversed by a plurality of global array lines. The memory array may include a three-dimensional memory array having more than one memory plane. Some of the NAND strings of the first group may be disposed on one memory plane, and some of the NAND strings of the second group may be disposed on another memory plane. In some cases, NAND strings of both groups may share global array lines.Type: GrantFiled: December 30, 2004Date of Patent: February 13, 2007Assignee: SanDisk 3D LLCInventors: Luca G. Fasoli, Roy E. Scheuerlein
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Patent number: 7177181Abstract: A memory array includes a sensing circuit for sensing bit line current while keeping the voltage of the selected bit line substantially unchanged. The word lines and bit lines are biased so that essentially no bias voltage is impressed across half-selected memory cells, which substantially eliminates leakage current through half-selected memory cells. The bit line current which is sensed arises largely from only the current through the selected memory cell. A noise detection line in the memory array reduces the effect of coupling from unselected word lines to the selected bit line. In a preferred embodiment, a three-dimensional memory array having a plurality of rail-stacks forming bit lines on more than one layer, includes at least one noise detection line associated with each layer of bit lines. A sensing circuit is connected to a selected bit line and to its associated noise detection line.Type: GrantFiled: June 29, 2001Date of Patent: February 13, 2007Assignee: SanDisk 3D LLCInventor: Roy E. Scheuerlein
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Patent number: 7176064Abstract: A memory cell is formed of a semiconductor junction diode in series with an antifuse. The cell is programmed by rupture of the antifuse. The semiconductor junction diode comprises silicon, the silicon crystallized in contact with a silicide. The suicide apparently provides a template for crystallization, improving crystallinity and conductivity of the diode, and reducing the programming voltage required to program the cell. It is advantageous to reduce a dielectric layer (such as an oxide, nitride, or oxynitride) intervening between the silicon and the silicon-forming metal during the step of forming the silicide.Type: GrantFiled: September 29, 2004Date of Patent: February 13, 2007Assignee: Sandisk 3D LLCInventor: S. Brad Herner
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Patent number: 7177183Abstract: Extremely dense memory cell structures provide for new array structures useful for implementing memory and logic functions. An exemplary non-volatile memory array includes a first plurality of X-lines configured to be logically identical in a read mode of operation, and each associated with a first Y-line group numbering at least one Y-line. Each of the first plurality of X-lines may also be associated with a second Y-line group numbering at least one Y-line. In some embodiments, the first and second Y-Line groups are simultaneously selectable in a read mode and, when so selected, are respectively coupled to true and complement inputs of a sense amplifier circuit. Such Y-line groups may number only one Y-line, or may number more than one Y-line. Many types of memory cells may be used, such as various passive element cells and EEPROM cells, in both 2D or 3D memory arrays.Type: GrantFiled: September 30, 2003Date of Patent: February 13, 2007Assignee: SanDisk 3D LLCInventors: Roy E. Scheuerlein, Luca Fasoli, Mark G. Johnson
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Patent number: 7174351Abstract: A digital storage system is coupled to a write-once memory array. File delete commands are implemented by over-writing a destructive digital pattern to at least a portion of the memory cells associated with the file to be deleted. One disclosed system alters the manner in which a file delete command is implemented, depending upon whether the file is stored in a write-once memory or in a re-writable memory.Type: GrantFiled: September 29, 2003Date of Patent: February 6, 2007Assignee: SanDisk 3D LLCInventors: Christopher S. Moore, Derek J. Bosch, Daniel C. Steere, J. James Tringali
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Patent number: 7160761Abstract: A very high density field programmable memory is disclosed. An array is formed vertically above a substrate using several layers, each layer of which includes vertically fabricated memory cells. The cell in an N level array may be formed with N+1 masking steps plus masking steps needed for contacts. Maximum use of self alignment techniques minimizes photolithographic limitations. In one embodiment the peripheral circuits are formed in a silicon substrate and an N level array is fabricated above the substrate.Type: GrantFiled: September 19, 2002Date of Patent: January 9, 2007Assignee: SanDisk 3D LLCInventors: James M. Cleeves, Vivek Subramanian
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Patent number: 7148570Abstract: Low resistivity, C54-phase TiSi2 is formed in narrow lines on heavily doped polysilicon by depositing a bi-layer silicon film. A thin, undoped amorphous layer is deposited on top of a heavily doped layer. The thickness of the undoped amorphous Si is about 2.4 times the thickness of the subsequently deposited Ti film. Upon thermal annealing above 750° C., the undoped amorphous Si is consumed by the reaction of Ti+Si to form TiSi2, forming a low-resistivity, C54-phase TiSi2 film on top of heavily doped polysilicon. The annealing temperature required to form C54 phase TiSi2 is reduced by consuming undoped amorphous Si in the reaction of Ti and Si, as compared with heavily doped polysilicon. Narrow lines (<0.3 ?m) of low-resistivity, C54-phase TiSi2 films on heavily doped polysilicon are thus achieved.Type: GrantFiled: August 13, 2001Date of Patent: December 12, 2006Assignee: SanDisk 3D LLCInventors: Scott Brad Herner, Michael A. Vyvoda
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Patent number: 7144807Abstract: Low resistivity, C54-phase TiSi2 is formed in narrow lines on heavily doped polysilicon by depositing a bi-layer silicon film. A thin, undoped amorphous layer is deposited on top of a heavily doped layer. The thickness of the undoped amorphous Si is about 2.4 times the thickness of the subsequently deposited Ti film. Upon thermal annealing above 750° C., the undoped amorphous Si is consumed by the reaction of Ti+Si to form TiSi2, forming a low-resistivity, C54-phase TiSi2 film on top of heavily doped polysilicon. The annealing temperature required to form C54 phase TiSi2 is reduced by consuming undoped amorphous Si in the reaction of Ti and Si, as compared with heavily doped polysilicon. Narrow lines (<0.3 ?m) of low-resistivity, C54-phase TiSi2 films on heavily doped polysilicon are thus achieved.Type: GrantFiled: September 18, 2002Date of Patent: December 5, 2006Assignee: SanDisk 3D LLCInventors: Scott Brad Herner, Michael A. Vyvoda
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Patent number: 7142471Abstract: An integrated circuit memory array includes alternating first and second types of memory blocks, each memory block including respective array lines shared with a respective array line in an adjacent memory block. The array lines of a defective block of one type are mapped into a spare block of the same type. The array lines of a first adjacent block which are shared with array lines of the defective block, and the array lines of a second adjacent block which are shared with array lines of the defective block, are mapped into a second spare block of the other type, thereby mapping the defective block and portions of both adjacent blocks into just two spare blocks.Type: GrantFiled: March 31, 2005Date of Patent: November 28, 2006Assignee: SanDisk 3D LLCInventors: Luca G. Fasoli, Roy E. Scheuerlein
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Publication number: 20060250837Abstract: In a novel nonvolatile memory cell formed above a substrate, a diode is paired with a reversible resistance-switching material, preferably a metal oxide or nitride such as, for example, NixOy, NbxOy, TixOy, HFxOy, AlxOy, MgxOy, CoxOy, CrxOy, VxOy, ZnxOy, ZrxOy, BxNy, and AlxNy. In preferred embodiments, the diode is formed as a vertical pillar disposed between conductors. Multiple memory levels can be stacked to form a monolithic three dimensional memory array. In some embodiments, the diode comprises germanium or a germanium alloy, which can be deposited and crystallized at relatively low temperatures, allowing use of aluminum or copper in the conductors. The memory cell of the present invention can be used as a rewriteable memory cell or a one-time-programmable memory cell, and can store two or more data states.Type: ApplicationFiled: March 31, 2006Publication date: November 9, 2006Applicant: SanDisk 3D, LLCInventors: S. Herner, Tanmay Kumar, Christopher Petti
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Patent number: 7132335Abstract: An array of transistors includes a plurality of transistors, a plurality of word lines extending in a first direction and a plurality of bit lines extending in a second direction. Each transistor includes a source, a drain, a channel and a localized charge storage dielectric. A first transistor of the plurality of transistors and a second transistor of the plurality of transistors share a common source/drain. A first localized charge storage dielectric of the first transistor does not overlap the common source/drain and a second localized charge storage dielectric of the second transistor overlaps the common source/drain.Type: GrantFiled: October 18, 2004Date of Patent: November 7, 2006Assignee: Sandisk 3D LLCInventors: Alper Ilkbahar, Roy Scheuerlein, Andrew J. Walker, Luca Fasoli
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Patent number: 7129538Abstract: There is provided a monolithic three dimensional array of charge storage devices which includes a plurality of device levels, wherein at least one surface between two successive device levels is planarized by chemical mechanical polishing.Type: GrantFiled: May 10, 2004Date of Patent: October 31, 2006Assignee: Sandisk 3D LLCInventors: Thomas H. Lee, Vivek Subramanian, James M. Cleeves, Andrew J. Walker, Christopher Petti, Igor G. Kouznetzov, Mark G. Johnson, Paul M. Farmwald, Brad Herner