Patents by Inventor Durai Vishak Nirmal Ramaswamy

Durai Vishak Nirmal Ramaswamy 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).

  • Patent number: 10608005
    Abstract: Methods and devices are disclosed, such as those involving memory cell devices with improved charge retention characteristics. In one or more embodiments, a memory cell is provided having an active area defined by sidewalls of neighboring trenches. A layer of dielectric material is blanket deposited over the memory cell, and etched to form spacers on sidewalls of the active area. Dielectric material is formed over the active area, a charge trapping structure is formed over the dielectric material over the active area, and a control gate is formed over the charge trapping structure. In some embodiments, the charge trapping structure includes nanodots. In some embodiments, the width of the spacers is between about 130% and about 170% of the thickness of the dielectric material separating the charge trapping material and an upper surface of the active area.
    Type: Grant
    Filed: February 3, 2014
    Date of Patent: March 31, 2020
    Assignee: Micron Technology, Inc.
    Inventors: Ronald A. Weimer, Kyu S. Min, Thomas M. Graettinger, Durai Vishak Nirmal Ramaswamy
  • Publication number: 20200090728
    Abstract: Methods, systems, and devices for operating a ferroelectric memory cell or cells are described. A cell may be written with a value that is intended to convey a different logic state than may typically be associated with the value. For example, a cell that has stored a charge associated with one logic state for a time period may be re-written to store a different charge, and the re-written cell may still be read to have the originally stored logic state. An indicator may be stored in a latch to indicate whether the logic state currently stored by the cell is the intended logic state of the cell. A cell may, for example, be re-written with an opposite value periodically, based on the occurrence of an event, or based on a determination that the cell has stored one value (or charge) for a certain time period.
    Type: Application
    Filed: September 27, 2019
    Publication date: March 19, 2020
    Inventors: Alessandro Calderoni, Durai Vishak Nirmal Ramaswamy, Kirk Prall, Ferdinando Bedeschi
  • Publication number: 20200075330
    Abstract: A method includes forming a first amorphous material, forming a second amorphous material over and in contact with the first material, removing a portion of the second material and the first material to form pillars, and exposing the materials to a temperature between a crystallization temperature of the first material and a crystallization temperature of the second material. The first material and the second material each comprise at least one element selected from the group consisting of silicon and germanium. The second material exhibits a crystallization temperature different than a crystallization temperature of the first material. Semiconductor structures, memory devices, and systems are also disclosed.
    Type: Application
    Filed: September 5, 2018
    Publication date: March 5, 2020
    Inventors: Ashonita A. Chavan, Durai Vishak Nirmal Ramaswamy, Michael Mutch, Sameer Chhajed
  • Publication number: 20200051849
    Abstract: Some embodiments include an integrated memory having an array of capacitors. The array has edges. The capacitors along the edges are edge capacitors, and the other capacitors are internal capacitors. The edge capacitors have inner edges facing toward the internal capacitors, and have outer edges in opposing relation to the inner edges. An insulative beam extends laterally between the capacitors. The insulative beam is along upper regions of the capacitors. First void regions are under the insulative beam, along lower regions of the internal capacitors, and along the inner edges of the edge capacitors. Peripheral extensions of the insulative beam extend laterally outward of the edge capacitors, and second void regions are under the peripheral extensions and along the outer edges of the edge capacitors. Some embodiments included integrated assemblies having two or more memory array decks stacked on atop another. Some embodiments include methods of forming memory arrays.
    Type: Application
    Filed: October 21, 2019
    Publication date: February 13, 2020
    Applicant: Micron Technology, Inc.
    Inventor: Durai Vishak Nirmal Ramaswamy
  • Patent number: 10553595
    Abstract: A memory cell includes a first electrode and a second electrode. A select device and a programmable device are in series with each other between the first and second electrodes. The select device is proximate and electrically coupled to the first electrode. The programmable device is proximate and electrically coupled to the second electrode. The programmable device includes a radially inner electrode having radially outer sidewalls. Ferroelectric material is radially outward of the outer sidewalls of the inner electrode. A radially outer electrode is radially outward of the ferroelectric material. One of the outer electrode or the inner electrode is electrically coupled to the select device. The other of the outer electrode and the inner electrode is electrically coupled to the second electrode. Arrays of memory cells are disclosed.
    Type: Grant
    Filed: June 13, 2018
    Date of Patent: February 4, 2020
    Assignee: Micron Technology, Inc.
    Inventors: Durai Vishak Nirmal Ramaswamy, Wayne Kinney, Marco Domenico Tiburzi
  • Patent number: 10553587
    Abstract: A method of forming an array of cross point memory cells comprises using two, and only two, masking steps to collectively pattern within the array spaced lower first lines, spaced upper second lines which cross the first lines, and individual programmable devices between the first lines and the second lines where such cross that have an upwardly open generally U-shape vertical cross-section of programmable material laterally between immediately adjacent of the first lines beneath individual of the upper second lines. Arrays of cross point memory cells independent of method of manufacture are disclosed.
    Type: Grant
    Filed: March 18, 2019
    Date of Patent: February 4, 2020
    Assignee: Micron Technology, Inc.
    Inventor: Durai Vishak Nirmal Ramaswamy
  • Publication number: 20200017839
    Abstract: A method of forming a tier of an array of memory cells within an array area, the memory cells individually comprising a capacitor and an elevationally-extending transistor, the method comprising using two, and only two, sacrificial masking steps within the array area of the tier in forming the memory cells. Other methods are disclosed, as are structures independent of method of fabrication.
    Type: Application
    Filed: September 25, 2019
    Publication date: January 16, 2020
    Applicant: Micron Technology, Inc.
    Inventor: Durai Vishak Nirmal Ramaswamy
  • Publication number: 20200020708
    Abstract: A method of forming an array comprising pairs of vertically opposed capacitors comprises forming a conductive lining in individual capacitor openings in support material. An elevational mid-portion of individual of the conductive linings is removed to form an upper capacitor electrode lining and a lower capacitor electrode lining that are elevationally separate and spaced from one another in the individual capacitor openings. A capacitor insulator is formed laterally outward of the upper and lower capacitor electrode linings. Conductive material is formed laterally outward of the capacitor insulator to comprise a shared capacitor electrode that is shared by vertically opposed capacitors in individual of the pairs of vertically opposed capacitors. Other methods and structure independent of method of manufacture are disclosed.
    Type: Application
    Filed: September 25, 2019
    Publication date: January 16, 2020
    Applicant: Micron Technology, Inc.
    Inventors: Ashonita A. Chavan, Durai Vishak Nirmal Ramaswamy
  • Patent number: 10529720
    Abstract: A method of forming an array of capacitors and access transistors there-above comprises forming access transistor trenches partially into insulative material. The trenches individually comprise longitudinally-spaced masked portions and longitudinally-spaced openings in the trenches longitudinally between the masked portions. The trench openings have walls therein extending longitudinally in and along the individual trench openings against laterally-opposing sides of the trenches. At least some of the insulative material that is under the trench openings is removed through bases of the trench openings between the walls and the masked portions to form individual capacitor openings in the insulative material that is lower than the walls. Individual capacitors are formed in the individual capacitor openings. A line of access transistors is formed in the individual trenches. The line of access transistors electrically couples to the individual capacitors that are along that line.
    Type: Grant
    Filed: January 3, 2019
    Date of Patent: January 7, 2020
    Assignee: Micron Technology, Inc.
    Inventors: Scott E. Sills, Durai Vishak Nirmal Ramaswamy
  • Publication number: 20190386015
    Abstract: A method of forming a ferroelectric memory cell. The method comprises forming an electrode material exhibiting a desired dominant crystallographic orientation. A hafnium-based material is formed over the electrode material and the hafnium-based material is crystallized to induce formation of a ferroelectric material having a desired crystallographic orientation. Additional methods are also described, as are semiconductor device structures including the ferroelectric material.
    Type: Application
    Filed: August 26, 2019
    Publication date: December 19, 2019
    Inventors: Qian Tao, Matthew N. Rocklein, Beth R. Cook, Durai Vishak Nirmal Ramaswamy
  • Publication number: 20190386063
    Abstract: A method of forming an array of memory cells includes forming lines of covering material that are elevationally over and along lines of spaced sense line contacts. Longitudinal orientation of the lines of covering material is used in forming lines comprising programmable material and outer electrode material that are between and along the lines of covering material. The covering material is removed over the spaced sense line contacts and the spaced sense line contacts are exposed. Access lines are formed. Sense lines are formed that are electrically coupled to the spaced sense line contacts. The sense lines are angled relative to the lines of spaced sense line contacts and relative to the access lines. Other embodiments, including structure independent of method, are disclosed.
    Type: Application
    Filed: August 30, 2019
    Publication date: December 19, 2019
    Applicant: Micron Technology, Inc.
    Inventors: Scott E. Sills, Durai Vishak Nirmal Ramaswamy
  • Publication number: 20190355803
    Abstract: A memory cell comprises a capacitor having a first conductive capacitor electrode having laterally-spaced walls that individually have a top surface. A second conductive capacitor electrode is laterally between the walls of the first capacitor electrode, and comprises a portion above the first capacitor electrode. Ferroelectric material is laterally between the walls of the first capacitor electrode and laterally between the second capacitor electrode and the first capacitor electrode. The capacitor comprises an intrinsic current leakage path from one of the first and second capacitor electrodes to the other through the ferroelectric material. A parallel current leakage path is between an elevationally-inner surface of the portion of the second capacitor electrode that is above the first capacitor electrode and at least one of the individual top surfaces of the laterally-spaced walls of the first capacitor electrode.
    Type: Application
    Filed: July 31, 2019
    Publication date: November 21, 2019
    Applicant: Micron Technology, Inc.
    Inventors: Muralikrishnan Balakrishnan, Beth R. Cook, Durai Vishak Nirmal Ramaswamy
  • Publication number: 20190348603
    Abstract: A memory cell comprising a threshold switching material over a first electrode on a substrate. The memory cell includes a second electrode over the threshold switching material and at least one dielectric material between the threshold switching material and at least one of the first electrode and the second electrode. A memory material overlies the second electrode. The dielectric material may directly contact the threshold switching material and each of the first electrode and the second electrode. Memory cells including only one dielectric material between the threshold switching material and an electrode are disclosed. A memory device including the memory cells and methods of forming the memory cells are also described.
    Type: Application
    Filed: July 24, 2019
    Publication date: November 14, 2019
    Inventors: Tsz W. Chan, Durai Vishak Nirmal Ramaswamy, Qian Tao, Yongjun Jeff Hu, Everett A. McTeer
  • Patent number: 10475697
    Abstract: Some embodiments include an integrated memory having an array of capacitors. The array has edges. The capacitors along the edges are edge capacitors, and the other capacitors are internal capacitors. The edge capacitors have inner edges facing toward the internal capacitors, and have outer edges in opposing relation to the inner edges. An insulative beam extends laterally between the capacitors. The insulative beam is along upper regions of the capacitors. First void regions are under the insulative beam, along lower regions of the internal capacitors, and along the inner edges of the edge capacitors. Peripheral extensions of the insulative beam extend laterally outward of the edge capacitors, and second void regions are under the peripheral extensions and along the outer edges of the edge capacitors. Some embodiments included integrated assemblies having two or more memory array decks stacked on atop another. Some embodiments include methods of forming memory arrays.
    Type: Grant
    Filed: May 17, 2018
    Date of Patent: November 12, 2019
    Assignee: Micron Technology, Inc.
    Inventor: Durai Vishak Nirmal Ramaswamy
  • Patent number: 10475500
    Abstract: Methods, systems, and devices for operating a ferroelectric memory cell or cells are described. A cell may be written with a value that is intended to convey a different logic state than may typically be associated with the value. For example, a cell that has stored a charge associated with one logic state for a time period may be re-written to store a different charge, and the re-written cell may still be read to have the originally stored logic state. An indicator may be stored in a latch to indicate whether the logic state currently stored by the cell is the intended logic state of the cell. A cell may, for example, be re-written with an opposite value periodically, based on the occurrence of an event, or based on a determination that the cell has stored one value (or charge) for a certain time period.
    Type: Grant
    Filed: August 23, 2018
    Date of Patent: November 12, 2019
    Assignee: Micron Technology, Inc.
    Inventors: Alessandro Calderoni, Durai Vishak Nirmal Ramaswamy, Kirk Prall, Ferdinando Bedeschi
  • Publication number: 20190333917
    Abstract: A transistor comprises semiconductor material that is generally L-shaped or generally mirror L-shaped in at least one straight-line vertical cross-section thereby having an elevationally-extending stem and a base extending horizontally from a lateral side of the stem above a bottom of the stem. The semiconductor material of the stern comprises an upper source/drain region and a channel region there-below. The transistor comprises at least one of (a) and (b), where (a): the semiconductor material of the stern comprises a lower source/drain region below the channel region, and (b): the semiconductor material of the base comprises a lower source/drain region. A gate is operatively laterally adjacent the channel region of the stem. Other embodiments are disclosed, including arrays of memory cells individually comprising a capacitor and an elevationally-extending transistor. Methods are disclosed.
    Type: Application
    Filed: June 11, 2019
    Publication date: October 31, 2019
    Applicant: Micron Technology, Inc.
    Inventor: Durai Vishak Nirmal Ramaswamy
  • Patent number: 10443046
    Abstract: A method of forming a tier of an array of memory cells within an array area, the memory cells individually comprising a capacitor and an elevationally-extending transistor, the method comprising using two, and only two, sacrificial masking steps within the array area of the tier in forming the memory cells. Other methods are disclosed, as are structures independent of method of fabrication.
    Type: Grant
    Filed: January 3, 2019
    Date of Patent: October 15, 2019
    Assignee: Micron Technology, Inc.
    Inventor: Durai Vishak Nirmal Ramaswamy
  • Patent number: 10431695
    Abstract: A transistor comprises a pair of source/drain regions having a channel region there-between. A transistor gate construction is operatively proximate the channel region. The channel region comprises a direction of current flow there-through between the pair of source/drain regions. The channel region comprises at least one of GaP, GaN, and GaAs extending all along the current-flow direction. Each of the source/drain regions comprises at least one of GaP, GaN, and GaAs extending completely through the respective source/drain region orthogonal to the current-flow direction. The at least one of the GaP, the GaN, and the GaAs of the respective source/drain region is directly against the at least one of the GaP, the GaN, and the GaAs of the channel region. Each of the source/drain regions comprises at least one of elemental silicon and metal material extending completely through the respective source/drain region orthogonal to the current-flow direction. Other embodiments are disclosed.
    Type: Grant
    Filed: December 20, 2017
    Date of Patent: October 1, 2019
    Assignee: Micron Technology, Inc.
    Inventor: Durai Vishak Nirmal Ramaswamy
  • Patent number: 10431285
    Abstract: Methods, systems, and devices for preventing disturb of untargeted memory cells during repeated access operations of target memory cells are described for a non-volatile memory array. Multiple memory cells may be in electronic communication with a common conductive line, and each memory cell may have an electrically non-linear selection component. Following an access operation (e.g., a read or write operation) of a target memory cell, untargeted memory cells may be discharged by applying a discharge voltage to the common conductive line. The discharge voltage may have a polarity opposite to the access voltage. A delay may be instituted between access attempts in order to discharge the untargeted memory cells.
    Type: Grant
    Filed: November 8, 2018
    Date of Patent: October 1, 2019
    Assignee: Micron Technology, Inc.
    Inventors: Bei Wang, Alessandro Calderoni, Wayne Kinney, Adam Johnson, Durai Vishak Nirmal Ramaswamy
  • Patent number: 10431629
    Abstract: A method of forming an array of memory cells includes forming lines of covering material that are elevationally over and along lines of spaced sense line contacts. Longitudinal orientation of the lines of covering material is used in forming lines comprising programmable material and outer electrode material that are between and along the lines of covering material. The covering material is removed over the spaced sense line contacts and the spaced sense line contacts are exposed. Access lines are formed. Sense lines are formed that are electrically coupled to the spaced sense line contacts. The sense lines are angled relative to the lines of spaced sense line contacts and relative to the access lines. Other embodiments, including structure independent of method, are disclosed.
    Type: Grant
    Filed: May 23, 2018
    Date of Patent: October 1, 2019
    Assignee: Micron Technology, Inc.
    Inventors: Scott E. Sills, Durai Vishak Nirmal Ramaswamy