Patents by Inventor Vinod Robert Purayath

Vinod Robert Purayath 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: 10790298
    Abstract: Methods and apparatus for forming a plurality of nonvolatile memory cells are provided herein. The method includes depositing in a stack of alternating insulator layers and memory cell layers a layer of silicon oxide, a layer of silicon nitride, and a layer of amorphous silicon; removing the layer of amorphous silicon while maintaining the layer of amorphous silicon in a recess of the memory cells; selectively oxidizing the layer of amorphous silicon and the layer of silicon nitride to remove the layer of amorphous silicon from the recess and the layer of silicon nitride from the insulator layers; and removing oxidizing material from the recess and the insulator layers such that the layer of silicon nitride remains only in the recess of each memory cell of the memory cell layers and the layer of silicon oxide remains on both the insulator layers and the memory cell layers.
    Type: Grant
    Filed: February 6, 2019
    Date of Patent: September 29, 2020
    Assignee: APPLIED MATERIALS, INC.
    Inventor: Vinod Robert Purayath
  • Publication number: 20200227433
    Abstract: Methods and apparatus for forming a plurality of nonvolatile memory cells are provided herein. The method includes depositing in a stack of alternating insulator layers and memory cell layers a layer of silicon oxide, a layer of silicon nitride, and a layer of amorphous silicon; removing the layer of amorphous silicon while maintaining the layer of amorphous silicon in a recess of the memory cells; selectively oxidizing the layer of amorphous silicon and the layer of silicon nitride to remove the layer of amorphous silicon from the recess and the layer of silicon nitride from the insulator layers; and removing oxidizing material from the recess and the insulator layers such that the layer of silicon nitride remains only in the recess of each memory cell of the memory cell layers and the layer of silicon oxide remains on both the insulator layers and the memory cell layers.
    Type: Application
    Filed: February 6, 2019
    Publication date: July 16, 2020
    Inventor: VINOD ROBERT PURAYATH
  • Publication number: 20200051994
    Abstract: A method of forming a memory device including a plurality of nonvolatile memory cells is provided. The method includes forming a hole in a stack of alternating insulator layers and memory cell layers. The stack extends from a bottom to a top, and the stack includes a plurality of insulator layers and plurality of memory cell layers. The method further includes depositing a first portion of a silicon channel layer. The first portion of the silicon channel layer extends from the bottom of the stack to the top of the stack. The method further includes adding a dopant layer over the first portion of the silicon channel layer. The dopant layer includes a first dopant. The method further includes depositing a second portion of the silicon channel layer. The second portion of the silicon channel layer extends from the bottom of the stack to the top of the stack.
    Type: Application
    Filed: October 3, 2018
    Publication date: February 13, 2020
    Inventors: Vinod Robert PURAYATH, Priyadarshi PANDA, Abhijit MALLICK, Srinivas GANDIKOTA
  • Patent number: 10468259
    Abstract: In a 3D NAND device, the charge trap region of a memory cell is formed as a separate charge-trap “island.” As a result, the charge-trap region of one memory cell is electrically isolated from charge-trap regions in adjacent memory cells. The charge trap region of one memory cell is separated from the charge trap regions of adjacent memory cells by a dielectric structure, such as a silicon oxide film. Alternatively, the charge trap region of a memory cell is separated from the charge trap regions of adjacent memory cells by an air, gas, or vacuum gap.
    Type: Grant
    Filed: April 30, 2018
    Date of Patent: November 5, 2019
    Assignee: APPLIED MATERIALS, INC.
    Inventors: Vinod Robert Purayath, Nitin K. Ingle
  • Publication number: 20180254187
    Abstract: In a 3D NAND device, the charge trap region of a memory cell is formed as a separate charge-trap “island.” As a result, the charge-trap region of one memory cell is electrically isolated from charge-trap regions in adjacent memory cells. The charge trap region of one memory cell is separated from the charge trap regions of adjacent memory cells by a dielectric structure, such as a silicon oxide film. Alternatively, the charge trap region of a memory cell is separated from the charge trap regions of adjacent memory cells by an air, gas, or vacuum gap.
    Type: Application
    Filed: April 30, 2018
    Publication date: September 6, 2018
    Inventors: Vinod Robert PURAYATH, Nitin K. INGLE
  • Patent number: 9960045
    Abstract: In a 3D NAND device, the charge trap region of a memory cell is formed as a separate charge-trap “island.” As a result, the charge-trap region of one memory cell is electrically isolated from charge-trap regions in adjacent memory cells. The charge trap region of one memory cell is separated from the charge trap regions of adjacent memory cells by a dielectric structure, such as a silicon oxide film. Alternatively, the charge trap region of a memory cell is separated from the charge trap regions of adjacent memory cells by an air, gas, or vacuum gap.
    Type: Grant
    Filed: February 2, 2017
    Date of Patent: May 1, 2018
    Assignee: Applied Materials, Inc.
    Inventors: Vinod Robert Purayath, Nitin K. Ingle
  • Patent number: 9698149
    Abstract: High-density semiconductor memory is provided with enhancements to gate-coupling and electrical isolation between discrete devices in non-volatile memory. The intermediate dielectric between control gates and charge storage regions is varied in the row direction, with different dielectric constants for the varied materials to provide adequate inter-gate coupling while protecting from fringing fields and parasitic capacitances. Electrical isolation is further provided, at least in part, by air gaps that are formed in the column (bit line) direction and/or air gaps that are formed in the row (word line) direction.
    Type: Grant
    Filed: January 13, 2015
    Date of Patent: July 4, 2017
    Assignee: SanDisk Technologies LLC
    Inventors: Vinod Robert Purayath, George Matamis, Henry Chien, James Kai, Yuan Zhang
  • Patent number: 9379120
    Abstract: High-density semiconductor memory utilizing metal control gate structures and air gap electrical isolation between discrete devices in these types of structures are provided. During gate formation and definition, etching the metal control gate layer(s) is separated from etching the charge storage layer to form protective sidewall spacers along the vertical sidewalls of the metal control gate layer(s). The sidewall spacers encapsulate the metal control gate layer(s) while etching the charge storage material to avoid contamination of the charge storage and tunnel dielectric materials. Electrical isolation is provided, at least in part, by air gaps that are formed in the row direction and/or air gaps that are formed in the column direction.
    Type: Grant
    Filed: July 22, 2013
    Date of Patent: June 28, 2016
    Assignee: SanDisk Technologies Inc.
    Inventors: Vinod Robert Purayath, Tuan Pham, Hiroyuki Kinoshita, Yuan Zhang, Henry Chin, James K Kai, Takashi W Orimoto, George Matamis, Henry Chien
  • Publication number: 20150123191
    Abstract: High-density semiconductor memory is provided with enhancements to gate-coupling and electrical isolation between discrete devices in non-volatile memory. The intermediate dielectric between control gates and charge storage regions is varied in the row direction, with different dielectric constants for the varied materials to provide adequate inter-gate coupling while protecting from fringing fields and parasitic capacitances. Electrical isolation is further provided, at least in part, by air gaps that are formed in the column (bit line) direction and/or air gaps that are formed in the row (word line) direction.
    Type: Application
    Filed: January 13, 2015
    Publication date: May 7, 2015
    Applicant: SanDisk Technologies Inc.
    Inventors: Vinod Robert Purayath, George Matamis, Henry Chien, James Kai, Yuan Zhang
  • Patent number: 8946048
    Abstract: High-density semiconductor memory is provided with enhancements to gate-coupling and electrical isolation between discrete devices in non-volatile memory. The intermediate dielectric between control gates and charge storage regions is varied in the row direction, with different dielectric constants for the varied materials to provide adequate inter-gate coupling while protecting from fringing fields and parasitic capacitances. Electrical isolation is further provided, at least in part, by air gaps that are formed in the column (bit line) direction and/or air gaps that are formed in the row (word line) direction.
    Type: Grant
    Filed: June 16, 2011
    Date of Patent: February 3, 2015
    Assignee: SanDisk Technologies Inc.
    Inventors: Vinod Robert Purayath, George Matamis, Henry Chien, James Kai, Yuan Zhang
  • Patent number: 8946803
    Abstract: Floating gates of a floating gate memory array have an inverted-T shape in both the bit line direction and the word line direction. Floating gates are formed using an etch stop layer that separates two polysilicon layers that form floating gates. Word lines extend over floating gates in one example, and word lines extend between floating gates in another example.
    Type: Grant
    Filed: December 6, 2007
    Date of Patent: February 3, 2015
    Assignee: SanDisk Technologies Inc.
    Inventors: George Matamis, Henry Chien, Vinod Robert Purayath, Takashi Whitney Orimoto, James Kai
  • Patent number: 8946022
    Abstract: Nanostructure-based charge storage regions are included in non-volatile memory devices and integrated with the fabrication of select gates and peripheral circuitry. One or more nanostructure coatings are applied over a substrate at a memory array area and a peripheral circuitry area. Various processes for removing the nanostructure coating from undesired areas of the substrate, such as target areas for select gates and peripheral transistors, are provided. One or more nanostructure coatings are formed using self-assembly based processes to selectively form nanostructures over active areas of the substrate in one example. Self-assembly permits the formation of discrete lines of nanostructures that are electrically isolated from one another without requiring patterning or etching of the nanostructure coating.
    Type: Grant
    Filed: February 22, 2013
    Date of Patent: February 3, 2015
    Assignee: SanDisk Technologies Inc.
    Inventors: Vinod Robert Purayath, James K Kai, Masaaki Higashitani, Takashi Orimoto, George Matamis, Henry Chien
  • Patent number: 8803220
    Abstract: Non-voltage storage and techniques for fabricating non-volatile storage are disclosed. In some embodiments, at least a portion of the control gates of non-volatile storage elements are formed from p-type polysilicon. In one embodiment, a lower portion of the control gate is p-type polysilicon. The upper portion of the control gate could be p-type polysilicon, n-type polysilicon, metal, metal nitride, etc. P-type polysilicon in the control gate may not deplete even at high Vpgm. Therefore, a number of problems that could occur if the control gate depleted are mitigated. For example, a memory cell having a control gate that is at least partially p-type polysilicon might be programmed with a lower Vpgm than a memory cell formed from n-type polysilicon.
    Type: Grant
    Filed: August 23, 2013
    Date of Patent: August 12, 2014
    Assignee: SanDisk Technologies Inc.
    Inventors: Takashi Whitney Orimoto, Atsushi Suyama, Ming Tian, Henry Chin, Henry Chien, Vinod Robert Purayath, Dana Lee
  • Publication number: 20130341700
    Abstract: Non-voltage storage and techniques for fabricating non-volatile storage are disclosed. In some embodiments, at least a portion of the control gates of non-volatile storage elements are formed from p-type polysilicon. In one embodiment, a lower portion of the control gate is p-type polysilicon. The upper portion of the control gate could be p-type polysilicon, n-type polysilicon, metal, metal nitride, etc. P-type polysilicon in the control gate may not deplete even at high Vpgm. Therefore, a number of problems that could occur if the control gate depleted are mitigated. For example, a memory cell having a control gate that is at least partially p-type polysilicon might be programmed with a lower Vpgm than a memory cell formed from n-type polysilicon.
    Type: Application
    Filed: August 23, 2013
    Publication date: December 26, 2013
    Applicant: SANDISK TECHNOLOGIES INC.
    Inventors: Takashi Whitney Orimoto, Atsushi Suyama, Ming Tian, Henry Chin, Henry Chien, Vinod Robert Purayath, Dana Lee
  • Publication number: 20130334587
    Abstract: High-density semiconductor memory utilizing metal control gate structures and air gap electrical isolation between discrete devices in these types of structures are provided. During gate formation and definition, etching the metal control gate layer(s) is separated from etching the charge storage layer to form protective sidewall spacers along the vertical sidewalls of the metal control gate layer(s). The sidewall spacers encapsulate the metal control gate layer(s) while etching the charge storage material to avoid contamination of the charge storage and tunnel dielectric materials. Electrical isolation is provided, at least in part, by air gaps that are formed in the row direction and/or air gaps that are formed in the column direction.
    Type: Application
    Filed: July 22, 2013
    Publication date: December 19, 2013
    Applicant: SanDisk Technologies Inc.
    Inventors: Vinod Robert Purayath, Tuan Pham, Hiroyuki Kinoshita, Yuan Zhang, Henry Chin, James K. Kai, Takashi W. Orimoto, George Matamis, Henry Chien
  • Patent number: 8603890
    Abstract: Air gap isolation in non-volatile memory arrays and related fabrication processes are provided. Electrical isolation between adjacent active areas of a substrate can be provided, at least in part, by bit line air gaps that are elongated in a column direction between the active areas. At least one cap is formed over each isolation region, at least partially overlying air to provide an upper endpoint for the corresponding air gap. The caps may be formed at least partially along the sidewalls of adjacent charge storage regions. In various embodiments, selective growth processes are used to form capping strips over the isolation regions to define the air gaps. Word line air gaps that are elongated in a row direction between adjacent rows of storage elements are also provided.
    Type: Grant
    Filed: June 16, 2011
    Date of Patent: December 10, 2013
    Assignee: SanDisk Technologies Inc.
    Inventors: Vinod Robert Purayath, George Matamis, Eli Harari, Hiroyuki Kinoshita, Tuan Pham
  • Patent number: 8546152
    Abstract: A method of fabricating non-volatile memory is provided for memory cells employing a charge storage element with multiple charge storage regions. A first charge storage layer is formed over a tunnel dielectric layer at both a memory array region and an endpoint region of a semiconductor substrate. The first charge storage layer is removed from the endpoint region to expose the tunnel dielectric region. A second charge storage layer is formed over the first charge storage layer at the memory array region and over the tunnel dielectric layer at the endpoint region. When etching the second charge storage layer to form the stem regions of the memory cells, the tunnel dielectric layer provides a detectable endpoint signal to indicate that etching for the second charge storage layer is complete.
    Type: Grant
    Filed: December 19, 2007
    Date of Patent: October 1, 2013
    Assignee: SanDisk Technologies Inc.
    Inventors: Takashi Orimoto, George Matamis, James Kai, Vinod Robert Purayath
  • Patent number: 8546214
    Abstract: Non-voltage storage and techniques for fabricating non-volatile storage are disclosed. In some embodiments, at least a portion of the control gates of non-volatile storage elements are formed from p-type polysilicon. In one embodiment, a lower portion of the control gate is p-type polysilicon. The upper portion of the control gate could be p-type polysilicon, n-type polysilicon, metal, metal nitride, etc. P-type polysilicon in the control gate may not deplete even at high Vpgm. Therefore, a number of problems that could occur if the control gate depleted are mitigated. For example, a memory cell having a control gate that is at least partially p-type polysilicon might be programmed with a lower Vpgm than a memory cell formed from n-type polysilicon.
    Type: Grant
    Filed: September 21, 2010
    Date of Patent: October 1, 2013
    Assignee: SanDisk Technologies Inc.
    Inventors: Takashi Whitney Orimoto, Atsushi Suyama, Ming Tian, Henry Chin, Henry Chien, Vinod Robert Purayath, Dana Lee
  • Patent number: 8546239
    Abstract: Air gap isolation in non-volatile memory arrays and related fabrication processes are provided. Electrical isolation can be provided, at least in part, by bit line air gaps that are elongated in a column direction and/or word line air gaps that are elongated in a row direction. The bit line air gaps may be formed in the substrate, extending between adjacent active areas of the substrate, as well as above the substrate surface, extending between adjacent columns of non-volatile storage elements. The word line air gaps may be formed above the substrate surface, extending between adjacent rows of non-volatile storage elements.
    Type: Grant
    Filed: June 9, 2011
    Date of Patent: October 1, 2013
    Assignee: SanDisk Technologies Inc.
    Inventors: Eli Harari, Tuan Pham, Yupin Fong, Vinod Robert Purayath
  • Patent number: 8492224
    Abstract: High-density semiconductor memory utilizing metal control gate structures and air gap electrical isolation between discrete devices in these types of structures are provided. During gate formation and definition, etching the metal control gate layer(s) is separated from etching the charge storage layer to form protective sidewall spacers along the vertical sidewalls of the metal control gate layer(s). The sidewall spacers encapsulate the metal control gate layer(s) while etching the charge storage material to avoid contamination of the charge storage and tunnel dielectric materials. Electrical isolation is provided, at least in part, by air gaps that are formed in the row direction and/or air gaps that are formed in the column direction.
    Type: Grant
    Filed: June 17, 2011
    Date of Patent: July 23, 2013
    Assignee: SanDisk Technologies Inc.
    Inventors: Vinod Robert Purayath, Tuan Pham, Hiroyuki Kinoshita, Yuan Zhang, Henry Chin, James K. Kai, Takashi W. Orimoto, George Matamis, Henry Chien