Patents Assigned to Sandisk 3D LLC
  • Patent number: 7618850
    Abstract: A method of making a nonvolatile memory device includes fabricating a diode in a low resistivity, programmed state without an electrical programming step. The memory device includes at least one memory cell. The memory cell is constituted by the diode and electrically conductive electrodes contacting the diode.
    Type: Grant
    Filed: March 30, 2007
    Date of Patent: November 17, 2009
    Assignee: SanDisk 3D LLC
    Inventors: Tanmay Kumar, S. Brad Herner
  • Publication number: 20090278112
    Abstract: Memory cells, and methods of forming such memory cells are provided that include a steering element coupled to a carbon-based reversible resistivity-switching material. In particular embodiments, methods in accordance with this invention etch a carbon nano-tube (“CNT”) film formed over a substrate, the methods including coating the substrate with a masking layer, patterning the masking layer, and etching the CNT film through the patterned masking layer using a non-oxygen based chemistry. Other aspects are also described.
    Type: Application
    Filed: April 10, 2009
    Publication date: November 12, 2009
    Applicant: SANDISK 3D LLC
    Inventors: April D. Schricker, Andy Fu, Michael Konevecki, Steven Maxwell
  • Patent number: 7615502
    Abstract: A method to laser anneal a silicon stack (or a silicon-rich alloy) including a heavily doped region buried beneath an undoped or lightly doped region is disclosed. By F selecting laser energy at a wavelength that tends to be transmitted by crystalline silicon and absorbed by amorphous silicon, crystallization progresses through the silicon layers in a manner that minimizes or prevents diffusion of dopants upward from the doped region to the undoped or lightly doped region. In preferred embodiments, the laser energy is pulsed, and a thermally conductive structure beneath the heavily doped layer dissipates heat, helping to control the anneal and limit dopant diffusion.
    Type: Grant
    Filed: December 16, 2005
    Date of Patent: November 10, 2009
    Assignee: Sandisk 3D LLC
    Inventor: Shuo Gu
  • Patent number: 7615436
    Abstract: There is provided a floating gate transistor, such as an EEPROM transistor, and method of making the transistor using two masking steps. The method of making a transistor includes patterning a floating gate layer using a first photoresist mask to form a floating gate rail and doping an active area using the floating gate rail as a mask to form source and drain regions in the active area. The method also includes patterning a control gate layer, a control gate dielectric layer, the floating gate rail, a tunnel dielectric layer and the active area using a second photoresist mask to form a control gate, a control gate dielectric, a floating gate, a tunnel dielectric and a channel island region.
    Type: Grant
    Filed: May 20, 2004
    Date of Patent: November 10, 2009
    Assignee: SanDisk 3D LLC
    Inventors: Igor G. Kouznetsov, Andrew J. Walker
  • Publication number: 20090273022
    Abstract: A monolithic three dimensional memory array is formed by a method that includes forming a first memory level above a substrate by i) forming a plurality of first substantially parallel conductors extending in a first direction, ii) forming first pillars above the first conductors, each first pillar comprising a first conductive layer or layerstack above a vertically oriented diode, the first pillars formed in a single photolithography step, iii) depositing a first dielectric layer above the first pillars, and iv) etching a plurality of substantially parallel first trenches in the first dielectric layer, the first trenches extending in a second direction, wherein, after the etching step, the lowest point in the trenches is above the lowest point of the first conductive layer or layerstack, wherein the first conductive layer or layerstack does not comprise a resistivity-switching metal oxide or nitride. The method also includes monolithically forming a second memory level above the first memory level.
    Type: Application
    Filed: July 14, 2009
    Publication date: November 5, 2009
    Applicant: SanDisk 3D LLC
    Inventors: Steven J. Radigan, Usha Raghuram, Samuel V. Dunton, Michael W. Konevecki
  • Publication number: 20090261343
    Abstract: Nonvolatile memory cells and methods of forming the same are provided, the methods including forming a first conductor at a first height above a substrate; forming a first pillar-shaped semiconductor element above the first conductor, wherein the first pillar-shaped semiconductor element comprises a first heavily doped layer of a first conductivity type, a second lightly doped layer above and in contact with the first heavily doped layer, and a third heavily doped layer of a second conductivity type above and in contact with the second lightly doped layer, the second conductivity type opposite the first conductivity type; forming a first dielectric antifuse above the third heavily doped layer of the first pillar-shaped semiconductor element; and forming a second conductor above the first dielectric antifuse.
    Type: Application
    Filed: June 3, 2009
    Publication date: October 22, 2009
    Applicant: SanDisk 3D LLC
    Inventors: S. Brad Herner, Maitreyee Mahajani
  • Publication number: 20090256131
    Abstract: In some aspects, a method of fabricating a memory cell is provided that includes: (1) fabricating a first conductor above a substrate; (2) selectively fabricating a carbon nano-tube (“CNT”) material above the first conductor by: (a) fabricating a CNT seeding layer on the first conductor, wherein the CNT seeding layer comprises silicon-germanium (“Si/Ge”), (b) planarizing a surface of the deposited CNT seeding layer, and (c) selectively fabricating CNT material on the CNT seeding layer; (3) fabricating a diode above the CNT material; and (4) fabricating a second conductor above the diode. Numerous other aspects are provided.
    Type: Application
    Filed: March 25, 2009
    Publication date: October 15, 2009
    Applicant: SANDISK 3D LLC
    Inventor: April D. Schricker
  • Publication number: 20090256130
    Abstract: In some aspects, a method of fabricating a memory cell is provided that includes fabricating a steering element above a substrate, and fabricating a reversible-resistance switching element coupled to the steering element by fabricating a carbon nano-tube (“CNT”) seeding layer by depositing a silicon-germanium layer above the substrate, patterning and etching the CNT seeding layer, and selectively fabricating CNT material on the CNT seeding layer. Numerous other aspects are provided.
    Type: Application
    Filed: March 25, 2009
    Publication date: October 15, 2009
    Applicant: SANDISK 3D LLC
    Inventor: April D. Schricker
  • Publication number: 20090257270
    Abstract: In some aspects, a microelectronic structure is provided that includes (1) a first conducting layer; (2) a first dielectric layer formed above the first conducting layer and having a feature that exposes a portion of the first conducting layer; (3) a graphitic carbon film disposed on a sidewall of the feature defined by the first dielectric layer and in contact with the first conducting layer at a bottom of the feature; and (4) a second conducting layer disposed above and in contact with the graphitic carbon film. Numerous other aspects are provided.
    Type: Application
    Filed: April 9, 2009
    Publication date: October 15, 2009
    Applicant: SANDISK 3D LLC
    Inventors: April D. Schricker, Mark H. Clark, Andy Fu, Huiwen Xu
  • Publication number: 20090256132
    Abstract: In accordance with aspects of the invention, a method of forming a memory cell is provided, the method including forming a steering element above a substrate, and forming a memory element coupled to the steering element, wherein the memory element comprises a carbon-based material having a thickness of not more than ten atomic layers. The memory element may be formed by repeatedly performing the following steps: forming a layer of a carbon-based material, the layer having a thickness of about one monolayer, and subjecting the layer of carbon-based material to a thermal anneal. Other aspects are also described.
    Type: Application
    Filed: April 6, 2009
    Publication date: October 15, 2009
    Applicant: SanDisk 3D LLC
    Inventors: Roy E. Scheuerlein, Alper Ilkbahar, April D. Schricker
  • Patent number: 7596050
    Abstract: Circuits and methods are described for decoding exemplary memory arrays of programmable and, in some embodiments, re-writable passive element memory cells, which are particularly useful for extremely dense three-dimensional memory arrays having more than one memory plane. In addition, circuits and methods are described for selecting one or more array blocks of such a memory array, for selecting one or more word lines and bit lines within selected array blocks, for conveying data information to and from selected memory cells within selected array blocks, and for conveying unselected bias conditions to unselected array blocks.
    Type: Grant
    Filed: July 31, 2006
    Date of Patent: September 29, 2009
    Assignee: SanDisk 3D LLC
    Inventors: Roy E. Scheuerlein, Luca G. Fasoli
  • Patent number: 7593249
    Abstract: Improved circuitry and methods for programming memory cells of a memory device are disclosed. The improved circuitry and methods operate to protect the memory cells from potentially damaging electrical energy that can be imposed during programming of the memory cells. Additionally, the improved circuitry and methods operate to detect when programming of the memory cells has been achieved. The improved circuitry and methods are particularly useful for programming non-volatile memory cells. In one embodiment, the memory device pertains to a semiconductor memory product, such as a semiconductor memory chip or a portable memory card.
    Type: Grant
    Filed: June 17, 2008
    Date of Patent: September 22, 2009
    Assignee: Sandisk 3D LLC
    Inventors: Luca G. Fasoli, Tyler Thorp
  • Publication number: 20090230571
    Abstract: A monolithic three dimensional semiconductor device structure includes a first layer including a first occurrence of a first reference mark at a first location, and a second layer including a second occurrence of the first reference mark at a second location, wherein the second location is substantially directly above the first location. The device structure also includes an intermediate layer between the first layer and the second layer, the intermediate layer including a blocking structure, wherein the blocking structure is vertically interposed between the first occurrence of the first reference mark and the second occurrence of the first reference mark. Other aspects are also described.
    Type: Application
    Filed: May 22, 2009
    Publication date: September 17, 2009
    Applicant: SANDISK 3D LLC
    Inventors: Yung-Tin Chen, Christopher J. Petti, Steven J. Radigan, Tanmay Kumar
  • Patent number: 7589989
    Abstract: Improved circuitry and methods operate to protect the memory cells from potentially damaging electrical energy that can be imposed during programming of the memory cells. Additionally, the improved circuitry and methods operate to detect when programming of the memory cells has been achieved. The improved circuitry and methods are particularly useful for programming non-volatile memory cells. In one embodiment, the memory device pertains to a semiconductor memory product, such as a semiconductor memory chip or a portable memory card.
    Type: Grant
    Filed: October 24, 2006
    Date of Patent: September 15, 2009
    Assignee: Sandisk 3D LLC
    Inventors: Luca G. Fasoli, Tyler Thorp
  • Publication number: 20090224244
    Abstract: Methods in accordance with the invention involve patterning and etching very small dimension pillars, such as in formation of a memory array in accordance with the invention. When dimensions of pillars become very small, the photoresist pillars used to pattern them may not have sufficient mechanical strength to survive the photoresist exposure and development process. Using methods according to the present invention, these photoresist pillars are printed and developed larger than their intended final dimension, such that they have increased mechanical strength, then are shrunk to the desired dimension during a preliminary etch performed before the etch of underlying material begins.
    Type: Application
    Filed: April 10, 2009
    Publication date: September 10, 2009
    Applicant: SANDISK 3D LLC
    Inventors: Usha Raghuram, Michael W. Konevecki
  • Patent number: 7586773
    Abstract: An upward-pointing p-i-n diode formed of deposited silicon, germanium, or silicon-germanium is disclosed. The diode has a bottom heavily doped p-type region, a middle intrinsic or lightly doped region, and a top heavily doped n-type region. The top heavily doped p-type region is doped with arsenic, and the semiconductor material of the diode is crystallized in contact with an appropriate silicide, germanide, or silicide-germanide. A large array of such upward-pointing diodes can be formed with excellent uniformity of current across the array when a voltage above the turn-on voltage of the diodes is applied. This diode is advantageously used in a monolithic three dimensional memory array.
    Type: Grant
    Filed: March 27, 2007
    Date of Patent: September 8, 2009
    Assignee: SanDisk 3D LLC
    Inventor: S. Brad Herner
  • Patent number: 7579232
    Abstract: A method of making a semiconductor device includes forming a pillar shaped semiconductor device surrounded by an insulating layer such that a contact hole in the insulating layer exposes an upper surface of the semiconductor device. The method also includes forming a shadow mask layer over the insulating layer such that a portion of the shadow mask layer overhangs a portion of the contact hole, forming a conductive layer such that a first portion of the conductive layer is located on the upper surface of the semiconductor device exposed in the contact hole and a second portion of the conductive layer is located over the shadow mask layer, and removing the shadow mask layer and the second portion of the conductive layer.
    Type: Grant
    Filed: July 11, 2008
    Date of Patent: August 25, 2009
    Assignee: SanDisk 3D LLC
    Inventors: Er-Xuan Ping, Randhir Thakur, Klaus Scheugraf
  • Patent number: 7580298
    Abstract: Methods and apparatus for managing electrical loads of electronic devices are disclosed. According to one embodiment, a current load imposed by an electronic device, such as a memory device (or memory system), can be measured. Then, using the measured current load, the memory device can determine whether (and to what extent) operational performance should be limited. By limiting operational performance, the memory device is able to limit its current load so as to satisfy a specification criterion or other requirement. The electrical load management is well suited for use in portable memory products (e.g., memory cards) to manage current loads being drawn.
    Type: Grant
    Filed: March 30, 2007
    Date of Patent: August 25, 2009
    Assignee: SanDisk 3D LLC
    Inventors: Tyler Thorp, Ken So
  • Patent number: 7580296
    Abstract: Methods and apparatus for managing electrical loads of electronic devices are disclosed. According to one embodiment, a current load imposed by an electronic device, such as a memory device (or memory system), can be measured. Then, using the measured current load, the memory device can determine whether (and to what extent) operational performance should be limited. By limiting operational performance, the memory device is able to limit its current load so as to satisfy a specification criterion or other requirement. The electrical load management is well suited for use in portable memory products (e.g., memory cards) to manage current loads being drawn.
    Type: Grant
    Filed: March 30, 2007
    Date of Patent: August 25, 2009
    Assignee: SanDisk 3D LLC
    Inventors: Tyler Thorp, Ken So
  • Patent number: 7575984
    Abstract: A method is provided for forming patterned features using a conductive hard mask, where the conductive hard mask protects those features during a subsequent trench etch to form Damascene conductors providing electrical connection to those features from above. The thickness of the hard mask provides a margin to avoid overetch during the trench etch which may be harmful to device performance. The method is advantageously used in formation of a monolithic three dimensional memory array.
    Type: Grant
    Filed: May 31, 2006
    Date of Patent: August 18, 2009
    Assignee: Sandisk 3D LLC
    Inventors: Steven J Radigan, Usha Raghuram, Samuel V Dunton, Michael W Konevecki