Patents by Inventor Vinod Purayath

Vinod 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: 11917821
    Abstract: In the highly efficient fabrication processes for HNOR arrays provided herein, the channel regions of the storage transistors in the HNOR arrays are protected by a protective layer after deposition until the subsequent deposition of a charge-trapping material before forming local word lines. Both the silicon for the channel regions and the protective material may be deposited in amorphous form and are subsequently crystallized in an anneal step. The protective material may be silicon boron, silicon carbon or silicon germanium. The protective material induces greater grain boundaries in the crystallized silicon in the channel regions, thereby providing greater charge carrier mobility, greater conductivity and greater current densities.
    Type: Grant
    Filed: November 16, 2021
    Date of Patent: February 27, 2024
    Assignee: SUNRISE MEMORY CORPORATION
    Inventors: Vinod Purayath, Wu-Yi Henry Chien
  • Publication number: 20240040798
    Abstract: Thin-film Ferroelectric field-effect transistor (FeFET) may be organized as 3-dimensional NOR memory string arrays. Each 3-dimensional NOR memory string array includes a row of active stack each including a predetermined number of active strips each provided one on top of another and each being spaced apart from another by an isolation layer. Each active strip may include a shared source layer and a shared drain layer shared by the FeFETs provided along the active strip. Data storage in the active strip is provided by ferroelectric elements that can individually electrically set into one of two polarization states. FeFETs on separate active strips may be configured for read, programming or erase operations in parallel.
    Type: Application
    Filed: October 9, 2023
    Publication date: February 1, 2024
    Inventors: Christopher J. Petti, Vinod Purayath, George Samachisa, Wu-Yi Henry Chien, Eli Harari
  • Patent number: 11844204
    Abstract: A process includes (a) providing a semiconductor substrate having a planar surface; (b) forming a plurality of thin-film layers above the planar surface of the semiconductor substrate, one on top of another, including among the thin-film layers first and second isolation layers, wherein a significantly greater concentration of a first dopant specie is provided in the first isolation layer than in the second isolation layer; (c) etching along a direction substantially orthogonal to the planar surface through the thin-films to create a trench having sidewalls that expose the thin-film layers; (d) depositing conformally a semiconductor material on the sidewalls of the trench; (e) annealing the first isolation layer at a predetermined temperature and a predetermined duration such that the first isolation layer act as a source of the first dopant specie which dopes a portion of the semiconductor material adjacent the first isolation layer; and (f) selectively etching the semiconductor material to remove the doped
    Type: Grant
    Filed: October 28, 2022
    Date of Patent: December 12, 2023
    Assignee: SUNRISE MEMORY CORPORATION
    Inventors: Vinod Purayath, Jie Zhou, Wu-Yi Henry Chien, Eli Harari
  • Patent number: 11839086
    Abstract: Thin-film Ferroelectric field-effect transistor (FeFET) may be organized as 3-dimensional NOR memory string arrays. Each 3-dimensional NOR memory string array includes a row of active stack each including a predetermined number of active strips each provided one on top of another and each being spaced apart from another by an isolation layer. Each active strip may include a shared source layer and a shared drain layer shared by the FeFETs provided along the active strip. Data storage in the active strip is provided by ferroelectric elements that can individually electrically set into one of two polarization states. FeFETs on separate active strips may be configured for read, programming or erase operations in parallel.
    Type: Grant
    Filed: July 13, 2022
    Date of Patent: December 5, 2023
    Assignee: SUNRISE MEMORY CORPORATION
    Inventors: Christopher J. Petti, Vinod Purayath, George Samachisa, Wu-Yi Henry Chien, Eli Harari
  • Patent number: 11751391
    Abstract: A process for building a 3-Dimensional NOR memory array avoids the challenge of etching a conductor material that is aimed at providing local word lines at a fine pitch. The process defines the local word lines between isolation shafts that may be carried out at a lower aspect ratio than would be required for etching the conductor material.
    Type: Grant
    Filed: July 21, 2021
    Date of Patent: September 5, 2023
    Assignee: SUNRISE MEMORY CORPORATION
    Inventors: Vinod Purayath, Yosuke Nosho, Shohei Kamisaka, Michiru Nakane, Eli Harari
  • Publication number: 20230247831
    Abstract: A process for building a 3-Dimensional NOR memory array avoids the challenge of etching a conductor material that is aimed at providing local word lines at a fine pitch. The process defines the local word lines between isolation shafts that may be carried out at a lower aspect ratio than would be required for etching the conductor material.
    Type: Application
    Filed: July 21, 2021
    Publication date: August 3, 2023
    Inventors: Vinod Purayath, Yosuke Nosho, Shohei Kamisaka, Michiru Nakane, Eli Harari
  • Publication number: 20230157019
    Abstract: In the highly efficient fabrication processes for HNOR arrays provided herein, the channel regions of the storage transistors in the HNOR arrays are protected by a protective layer after deposition until the subsequent deposition of a charge-trapping material before forming local word lines. Both the silicon for the channel regions and the protective material may be deposited in amorphous form and are subsequently crystallized in an anneal step. The protective material may be silicon boron, silicon carbon or silicon germanium. The protective material induces greater grain boundaries in the crystallized silicon in the channel regions, thereby providing greater charge carrier mobility, greater conductivity and greater current densities.
    Type: Application
    Filed: November 16, 2021
    Publication date: May 18, 2023
    Applicant: SUNRISE MEMORY CORPORATION
    Inventors: Vinod Purayath, Wu-Yi Henry Chien
  • Publication number: 20230072345
    Abstract: A process includes (a) providing a semiconductor substrate having a planar surface; (b) forming a plurality of thin-film layers above the planar surface of the semiconductor substrate, one on top of another, including among the thin-film layers first and second isolation layers, wherein a significantly greater concentration of a first dopant specie is provided in the first isolation layer than in the second isolation layer; (c) etching along a direction substantially orthogonal to the planar surface through the thin-films to create a trench having sidewalls that expose the thin-film layers; (d) depositing conformally a semiconductor material on the sidewalls of the trench; (e) annealing the first isolation layer at a predetermined temperature and a predetermined duration such that the first isolation layer act as a source of the first dopant specie which dopes a portion of the semiconductor material adjacent the first isolation layer; and (f)selectively etching the semiconductor material to remove the doped p
    Type: Application
    Filed: October 28, 2022
    Publication date: March 9, 2023
    Inventors: Vinod Purayath, Jie Zhou, Wu-Yi Henry Chien, Eli Harari
  • Publication number: 20230027837
    Abstract: Thin-film Ferroelectric field-effect transistor (FeFET) may be organized as 3-dimensional NOR memory string arrays. Each 3-dimensional NOR memory string array includes a row of active stack each including a predetermined number of active strips each provided one on top of another and each being spaced apart from another by an isolation layer. Each active strip may include a shared source layer and a shared drain layer shared by the FeFETs provided along the active strip. Data storage in the active strip is provided by ferroelectric elements that can individually electrically set into one of two polarization states. FeFETs on separate active strips may be configured for read, programming or erase operations in parallel.
    Type: Application
    Filed: July 13, 2022
    Publication date: January 26, 2023
    Inventors: Christopher J. Petti, Vinod Purayath, George Samachisa, Wu-Yi Henry Chien, Eli Harari
  • Publication number: 20220383953
    Abstract: A method for forming a three-dimensional memory structure above a semiconductor substrate includes forming two or more active stack sections, each formed on top of each other and separated by a dielectric buffer layer, where each active stack section includes multilayers separated by isolation dielectric layers and trenches with shafts filled with a sacrificial material. After the multiple active stack sections are formed, the method removes the sacrificial material in the shafts and removes portions of the dielectric buffer layer between shafts of adjacent active stack sections. The method fills the openings with a gate dielectric layer and a gate conductor. In some embodiments, the gate dielectric layer is discontinuous in the shaft over the depth of the multiple active stack sections.
    Type: Application
    Filed: April 26, 2022
    Publication date: December 1, 2022
    Inventors: Shohei Kamisaka, Vinod Purayath, Jie Zhou
  • Patent number: 11515309
    Abstract: A process includes (a) providing a semiconductor substrate having a planar surface; (b) forming a plurality of thin-film layers above the planar surface of the semiconductor substrate, one on top of another, including among the thin-film layers first and second isolation layers, wherein a significantly greater concentration of a first dopant specie is provided in the first isolation layer than in the second isolation layer; (c) etching along a direction substantially orthogonal to the planar surface through the thin-films to create a trench having sidewalls that expose the thin-film layers; (d) depositing conformally a semiconductor material on the sidewalls of the trench; (e) annealing the first isolation layer at a predetermined temperature and a predetermined duration such that the first isolation layer act as a source of the first dopant specie which dopes a portion of the semiconductor material adjacent the first isolation layer; and (f) selectively etching the semiconductor material to remove the doped
    Type: Grant
    Filed: December 17, 2020
    Date of Patent: November 29, 2022
    Assignee: SUNRISE MEMORY CORPORATION
    Inventors: Vinod Purayath, Jie Zhou, Wu-Yi Henry Chien, Eli Harari
  • Publication number: 20220344364
    Abstract: Carbon has many advantageous uses as a sacrificial material in the fabricating thin-film storage transistors, such as those organized as NOR memory strings. In one implementation, the carbon layers are replaced by heavily doped n-type polysilicon source and drain regions at a late step during device fabrication. As a result, many high temperature steps within the fabrication process may now be carried out without concern for thermal diffusion from the heavily doped polysilicon, thus allowing phosphorus to be used as the n-type dopant.
    Type: Application
    Filed: April 6, 2022
    Publication date: October 27, 2022
    Inventors: Vinod Purayath, Wu-Yi Henry Chien, Eli Harari
  • Publication number: 20220343980
    Abstract: A process for fabricating a three-dimensional NOR memory string of storage transistors implements a channel-last fabrication process with channel replacement using silicon germanium (SiGe). In particular, the process uses silicon germanium as a sacrificial layer, to be replaced with the channel material after the charge-storage layer of the storage transistors is formed. In this manner, the channel region is prevented from experiencing excessive high-temperature processing steps, such as during the annealing of the charge-storage layer.
    Type: Application
    Filed: April 18, 2022
    Publication date: October 27, 2022
    Inventors: Shohei Kamisaka, Vinod Purayath
  • Publication number: 20220231040
    Abstract: A VNOR memory string includes: (a) first and second pillars embedded in multiple composite layers, each composite layer comprising an insulator layer and a conductor layer, the first and second pillars each comprising a first semiconductor material of a first conductivity; (b) a second semiconductor layer of a second conductivity type opposite the first conductivity type on the outside of third pillar also embedded in the composite layers, the third pillar contacting both the first and second pillars; and (c) a storage layer provided between the second semiconductor layer and each of the conductor layer in the composite layers.
    Type: Application
    Filed: December 22, 2021
    Publication date: July 21, 2022
    Inventors: Vinod Purayath, Kenta Ohama, Yosuke Nosho
  • Publication number: 20220173251
    Abstract: By harnessing the ferroelectric phases in the charge storage material of thin-film storage transistors of a 3-dimensional array of NOR memory strings, the storage transistors are adapted to operate as ferroelectric field-effect transistors (“FeFETs”), thereby providing a very high-speed, high-density memory array.
    Type: Application
    Filed: February 17, 2022
    Publication date: June 2, 2022
    Inventors: George Samachisa, Vinod Purayath, Wu-Yi Henry Chien, Eli Harari
  • Publication number: 20220028886
    Abstract: A process for building a 3-Dimensional NOR memory array avoids the challenge of etching a conductor material that is aimed at providing local word lines at a fine pitch. The process defines the local word lines between isolation shafts that may be carried out at a lower aspect ratio than would be required for etching the conductor material.
    Type: Application
    Filed: July 21, 2021
    Publication date: January 27, 2022
    Inventors: Vinod Purayath, Yosuke Nosho, Shohei Kamisaka, Michiru Nakane, Eli Harari
  • Publication number: 20220028876
    Abstract: A process for manufacturing a 3-D NOR memory array provides thin-film storage transistors of each NOR memory string in either shafts or portions of a trench between adjacent shafts.
    Type: Application
    Filed: July 21, 2021
    Publication date: January 27, 2022
    Inventors: Vinod Purayath, Eli Harari
  • Patent number: 11217600
    Abstract: In the highly efficient fabrication processes for HNOR arrays provided herein, the channel regions of the storage transistors in the HNOR arrays are protected by a protective layer after deposition until the subsequent deposition of a charge-trapping material before forming local word lines. Both the silicon for the channel regions and the protective material may be deposited in amorphous form and are subsequently crystallized in an anneal step. The protective material may be silicon boron, silicon carbon or silicon germanium. The protective material induces greater grain boundaries in the crystallized silicon in the channel regions, thereby providing greater charge carrier mobility, greater conductivity and greater current densities.
    Type: Grant
    Filed: July 9, 2020
    Date of Patent: January 4, 2022
    Assignee: SUNRISE MEMORY CORPORATION
    Inventors: Vinod Purayath, Wu-Yi Henry Chien
  • Publication number: 20210193660
    Abstract: A process includes (a) providing a semiconductor substrate having a planar surface; (b) forming a plurality of thin-film layers above the planar surface of the semiconductor substrate, one on top of another, including among the thin-film layers first and second isolation layers, wherein a significantly greater concentration of a first dopant specie is provided in the first isolation layer than in the second isolation layer; (c) etching along a direction substantially orthogonal to the planar surface through the thin-films to create a trench having sidewalls that expose the thin-film layers; (d) depositing conformally a semiconductor material on the sidewalls of the trench; (e) annealing the first isolation layer at a predetermined temperature and a predetermined duration such that the first isolation layer act as a source of the first dopant specie which dopes a portion of the semiconductor material adjacent the first isolation layer; and (f) selectively etching the semiconductor material to remove the doped
    Type: Application
    Filed: December 17, 2020
    Publication date: June 24, 2021
    Inventors: Vinod Purayath, Jie Zhou, Wu-Yi Henry Chien, Eli Harari
  • Publication number: 20210013224
    Abstract: In the highly efficient fabrication processes for HNOR arrays provided herein, the channel regions of the storage transistors in the HNOR arrays are protected by a protective layer after deposition until the subsequent deposition of a charge-trapping material before forming local word lines. Both the silicon for the channel regions and the protective material may be deposited in amorphous form and are subsequently crystallized in an anneal step. The protective material may be silicon boron, silicon carbon or silicon germanium. The protective material induces greater grain boundaries in the crystallized silicon in the channel regions, thereby providing greater charge carrier mobility, greater conductivity and greater current densities.
    Type: Application
    Filed: July 9, 2020
    Publication date: January 14, 2021
    Applicant: SUNRISE MEMORY CORPORATION
    Inventors: Vinod Purayath, Wu-Yi Henry Chien