Patents by Inventor David H. Wells

David H. Wells 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: 20170179383
    Abstract: A three-dimensional variable resistance memory array and method of forming the same. The memory array has memory cells in multiple planes in three dimensions. The planes of the memory cells include shared interconnect lines, dually connected to driving and sensing circuits, that are used for addressing the cells for programming and reading. The memory array is formed using only a single patterned mask per central array plane to form the memory cells of such planes.
    Type: Application
    Filed: February 20, 2017
    Publication date: June 22, 2017
    Inventor: David H. Wells
  • Patent number: 9673102
    Abstract: Methods of forming a memory device having an array portion including a plurality of array transistors and a periphery region including peripheral circuit transistor structures of the memory device, where an upper surface of the periphery region and an upper surface of the array portion are planar (or nearly planar) after formation of the peripheral circuit transistor structures and a plurality of memory cells (formed over the array transistors). The method includes forming the peripheral circuit transistor structures in the periphery region, forming the plurality of array transistors in the array portion and forming a plurality of memory cells over respective vertical transistors. Structures formed by the method have planar upper surfaces of the periphery and array regions.
    Type: Grant
    Filed: April 1, 2011
    Date of Patent: June 6, 2017
    Assignee: MICRON TECHNOLOGY, INC.
    Inventors: Jun Liu, Sanh D. Tang, David H. Wells
  • Patent number: 9614151
    Abstract: A three dimensional variable resistance memory array and method of forming the same. The memory array has memory cells in multiple planes in three dimensions. The planes of the memory cells include shared interconnect lines, dually connected to driving and sensing circuits, that are used for addressing the cells for programming and reading. The memory array is formed using only a single patterned mask per central array plane to form the memory cells of such planes.
    Type: Grant
    Filed: February 11, 2014
    Date of Patent: April 4, 2017
    Assignee: MICRON TECHNOLOGY, INC.
    Inventor: David H. Wells
  • Publication number: 20160329377
    Abstract: The present disclosure includes select devices and methods of using select device for memory cell applications. An example select device includes a first electrode having a particular geometry, a semiconductor material formed on the first electrode and a second electrode having the particular geometry with formed on the semiconductor material, wherein the select device is configured to snap between resistive states in response to signals that are applied to the select device.
    Type: Application
    Filed: July 21, 2016
    Publication date: November 10, 2016
    Inventors: David H. Wells, Christopher D. Cardon, Caner Onal
  • Patent number: 9478497
    Abstract: Single spacer processes for multiplying pitch by a factor greater than two are provided. In one embodiment, n, where n?2, tiers of stacked mandrels are formed over a substrate, each of the n tiers comprising a plurality of mandrels substantially parallel to one another. Mandrels at tier n are over and parallel to mandrels at tier n?1, and the distance between adjoining mandrels at tier n is greater than the distance between adjoining mandrels at tier n?1. Spacers are simultaneously formed on sidewalls of the mandrels. Exposed portions of the mandrels are etched away and a pattern of lines defined by the spacers is transferred to the substrate.
    Type: Grant
    Filed: October 30, 2014
    Date of Patent: October 25, 2016
    Assignee: Micron Technology, Inc.
    Inventors: David H. Wells, Mirzafer K. Abatchev
  • Publication number: 20160276028
    Abstract: Memory devices comprise a plurality of memory cells, each memory cell including a memory element and a selection device. A plurality of first (e.g., row) address lines can be adjacent (e.g., under) a first side of at least some cells of the plurality. A plurality of second (e.g., column) address lines extend across the plurality of row address lines, each column address line being adjacent (e.g., over) a second, opposing side of at least some of the cells. Control circuitry can be configured to selectively apply a read voltage or a write voltage substantially simultaneously to the address lines. Systems including such memory devices and methods of accessing a plurality of cells at least substantially simultaneously are also disclosed.
    Type: Application
    Filed: May 26, 2016
    Publication date: September 22, 2016
    Inventors: David H. Wells, Jun Liu
  • Publication number: 20160260664
    Abstract: Methods of forming semiconductor structures that include bodies of a semiconductor material disposed between rails of a dielectric material are disclosed. Such methods may include filling a plurality of trenches in a substrate with a dielectric material and removing portions of the substrate between the dielectric material to form a plurality of openings. In some embodiments, portions of the substrate may be undercut to form a continuous void underlying the bodies and the continuous void may be filled with a conductive material. In other embodiments, portions of the substrate exposed within the openings may be converted to a silicide material to form a conductive material under the bodies. For example, the conductive material may be used as a conductive line to electrically interconnect memory device components. Semiconductor structures and devices formed by such methods are also disclosed.
    Type: Application
    Filed: May 10, 2016
    Publication date: September 8, 2016
    Inventors: David H. Wells, Gurtej S. Sandhu
  • Patent number: 9425390
    Abstract: The present disclosure includes select devices and methods of using select device for memory cell applications. An example select device includes a first electrode having a particular geometry, a semiconductor material formed on the first electrode and a second electrode having the particular geometry with formed on the semiconductor material, wherein the select device is configured to snap between resistive states in response to signals that are applied to the select device.
    Type: Grant
    Filed: October 16, 2014
    Date of Patent: August 23, 2016
    Assignee: Micron Technology, Inc.
    Inventors: David H. Wells, Christopher D. Cardon, Caner Onal
  • Patent number: 9361979
    Abstract: Memory devices comprise a plurality of memory cells, each memory cell including a memory element and a selection device. A plurality of first (e.g., row) address lines can be adjacent (e.g., under) a first side of at least some cells of the plurality. A plurality of second (e.g., column) address lines extend across the plurality of row address lines, each column address line being adjacent (e.g., over) a second, opposing side of at least some of the cells. Control circuitry can be configured to selectively apply a read voltage or a write voltage substantially simultaneously to the address lines. Systems including such memory devices and methods of accessing a plurality of cells at least substantially simultaneously are also disclosed.
    Type: Grant
    Filed: May 1, 2015
    Date of Patent: June 7, 2016
    Assignee: Micron Technology, Inc.
    Inventors: David H. Wells, Jun Liu
  • Patent number: 9362418
    Abstract: Semiconductor structures that include bodies of a semiconductor material spaced apart from an underlying substrate. The bodies may be physically separated from the substrate by at least one of a dielectric material, an open volume and a conductive material. The bodies may be electrically coupled by one or more conductive structures, which may be used as an interconnect structure to electrically couple components of memory devices. By providing isolation between the bodies, the semiconductor structure provides the properties of a conventional SOI substrate (e.g., high speed, low power, increased device density and isolation) while substantially reducing fabrication acts and costs associated with such SOI substrates. Additionally, the semiconductor structures of the present disclosure provide reduced parasitic coupling and current leakage due to the isolation of the bodies by the intervening dielectric material.
    Type: Grant
    Filed: January 27, 2015
    Date of Patent: June 7, 2016
    Assignee: Micron Technology, Inc.
    Inventors: Sanh D. Tang, David H. Wells, Tuman E. Allen
  • Patent number: 9355897
    Abstract: Methods of forming semiconductor structures that include bodies of a semiconductor material disposed between rails of a dielectric material are disclosed. Such methods may include filling a plurality of trenches in a substrate with a dielectric material and removing portions of the substrate between the dielectric material to form a plurality of openings. In some embodiments, portions of the substrate may be undercut to form a continuous void underlying the bodies and the continuous void may be filled with a conductive material. In other embodiments, portions of the substrate exposed within the openings may be converted to a silicide material to form a conductive material under the bodies. For example, the conductive material may be used as a conductive line to electrically interconnect memory device components. Semiconductor structures and devices formed by such methods are also disclosed.
    Type: Grant
    Filed: January 28, 2015
    Date of Patent: May 31, 2016
    Assignee: MICRON TECHNOLOGY, INC.
    Inventors: David H. Wells, Gurtej S. Sandhu
  • Patent number: 9356096
    Abstract: Disclosed are methods and resulting structures which provide an opening for epitaxial growth, the opening having an associated projection for reducing the size of the contact area on a substrate at which growth begins. During growth, the epitaxial material grows vertically from the contact area and laterally over the projection. The projection provides a stress relaxation region for the lateral growth to reduce dislocation and stacking faults at the side edges of the grown epitaxial material.
    Type: Grant
    Filed: July 20, 2015
    Date of Patent: May 31, 2016
    Assignee: Micron Technology, Inc.
    Inventors: Song Guo, Yushi Hu, Roy Meade, Sanh D. Tang, Michael P. Violette, David H. Wells
  • Patent number: 9349445
    Abstract: Select devices for memory cell applications and methods of forming the same are described herein. As an example, one or more non-ohmic select devices can include at least two tunnel barrier regions formed between a first metal material and a second metal material, and a third metal material formed between each of the respective at least two tunnel barrier regions. The non-ohmic select device is a two terminal select device that supports bi-directional current flow therethrough.
    Type: Grant
    Filed: September 16, 2011
    Date of Patent: May 24, 2016
    Assignee: Micron Technology, Inc.
    Inventors: David H. Wells, Bhaskar Srinivasan, John K. Zahurak
  • Publication number: 20160111639
    Abstract: The present disclosure includes select devices and methods of using select device for memory cell applications. An example select device includes a first electrode having a particular geometry, a semiconductor material formed on the first electrode and a second electrode having the particular geometry with formed on the semiconductor material, wherein the select device is configured to snap between resistive states in response to signals that are applied to the select device.
    Type: Application
    Filed: October 16, 2014
    Publication date: April 21, 2016
    Inventors: David H. Wells, Christopher D. Cardon, Caner Onal
  • Patent number: 9269899
    Abstract: An electronic device includes two conductive electrodes. A first current path extends from one of the electrodes to the other and has a dominant thermally activated conduction activation energy of 0.5 eV to 3.0 eV. A second current path extends from the one electrode to the other and is circuit-parallel the first current path. The second current path exhibits a minimum 100-times increase in electrical conductivity for increasing temperature within a temperature range of no more than 50° C. between 300° C. and 800° C. and exhibits a minimum 100-times decrease in electrical conductivity for decreasing temperature within the 50° C. temperature range. Other embodiments are disclosed.
    Type: Grant
    Filed: February 5, 2015
    Date of Patent: February 23, 2016
    Assignee: Micron Technology, Inc.
    Inventors: Kamal M. Karda, Marko Milojevic, David H. Wells, F. Daniel Gealy
  • Publication number: 20150325645
    Abstract: Disclosed are methods and resulting structures which provide an opening for epitaxial growth, the opening having an associated projection for reducing the size of the contact area on a substrate at which growth begins. During growth, the epitaxial material grows vertically from the contact area and laterally over the projection. The projection provides a stress relaxation region for the lateral growth to reduce dislocation and stacking faults at the side edges of the grown epitaxial material.
    Type: Application
    Filed: July 20, 2015
    Publication date: November 12, 2015
    Inventors: Song Guo, Yushi Hu, Roy Meade, Sanh D. Tang, Michael P. Violette, David H. Wells
  • Publication number: 20150325791
    Abstract: Methods of forming arrays of small, densely spaced holes or pillars for use in integrated circuits are disclosed. Various pattern transfer and etching steps can be used, in combination with pitch-reduction techniques, to create densely-packed features. Conventional photolithography steps can be used in combination with pitch-reduction techniques to form superimposed patterns of crossing elongate features with pillars at the intersections. Spacers are simultaneously applied to sidewalls of both sets of crossing lines to produce a pitch-doubled grid pattern. The pillars facilitate rows of spacers bridging columns of spacers.
    Type: Application
    Filed: June 29, 2015
    Publication date: November 12, 2015
    Inventor: David H. Wells
  • Patent number: 9142767
    Abstract: Resistive memory cells including an integrated select device and storage element and methods of forming the same are described herein. As an example, a resistive memory cell can include a select device structure including a Schottky interface, and a storage element integrated with the select device structure such that an electrode corresponding to the Schottky interface serves as a first electrode of the storage element. The storage element can include a storage material formed between the first electrode and a second electrode.
    Type: Grant
    Filed: September 16, 2011
    Date of Patent: September 22, 2015
    Assignee: Micron Technology, Inc.
    Inventors: David H. Wells, D. V. Nirmal Ramaswamy, Kirk D. Prall
  • Patent number: 9136472
    Abstract: Resistive memory and methods of processing resistive memory are described herein. One or more method embodiments of processing resistive memory include forming a resistive memory cell material on an electrode having an access device contact, and forming a heater electrode on the resistive memory cell material after forming the resistive memory cell material on the electrode such that the heater electrode is self-aligned to the resistive memory cell material.
    Type: Grant
    Filed: June 12, 2014
    Date of Patent: September 15, 2015
    Assignee: Micron Technology, Inc.
    Inventor: David H. Wells
  • Publication number: 20150249032
    Abstract: Some embodiments include methods of forming voids within semiconductor constructions. In some embodiments the voids may be utilized as microstructures for distributing coolant, for guiding electromagnetic radiation, or for separation and/or characterization of materials. Some embodiments include constructions having micro-structures therein which correspond to voids, conduits, insulative structures, semiconductor structures or conductive structures.
    Type: Application
    Filed: May 14, 2015
    Publication date: September 3, 2015
    Inventor: David H. Wells