Patents by Inventor Keerti Shukla

Keerti Shukla 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: 10361213
    Abstract: Memory stack structures are formed through an alternating stack of insulating layers and sacrificial material layers. Backside recesses are formed by removal of the sacrificial material layers selective to the insulating layers and the memory stack structures. A barrier layer stack including a crystalline electrically conductive barrier layer and an amorphous barrier layer is formed in the backside recesses prior to formation of a metal fill material layer.
    Type: Grant
    Filed: April 10, 2017
    Date of Patent: July 23, 2019
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Rahul Sharangpani, Fumitaka Amano, Raghuveer S. Makala, Fei Zhou, Keerti Shukla
  • Patent number: 10355139
    Abstract: Memory stack structures are formed through an alternating stack of insulating layers and sacrificial material layers. Backside recesses are formed by removal of the sacrificial material layers selective to the insulating layers and the memory stack structures. An electrically conductive, amorphous barrier layer can be formed prior to formation of a metal fill material layer to provide a diffusion barrier that reduces fluorine diffusion between the metal fill material layer and memory films of memory stack structures. The electrically conductive, amorphous barrier layer can be an oxygen-containing titanium compound or a ternary transition metal nitride.
    Type: Grant
    Filed: October 12, 2016
    Date of Patent: July 16, 2019
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Rahul Sharangpani, Raghuveer S. Makala, Keerti Shukla, Fei Zhou, Somesh Peri
  • Patent number: 10262945
    Abstract: A three-dimensional memory device includes driver transistors containing boron doped semiconductor active regions, device contact via structures in physical contact with the boron doped semiconductor active regions, the device contact via structures containing at least one of tantalum, tungsten, and cobalt, and a three-dimensional memory array located over the driver transistors and including an alternating stack of insulating layers and electrically conductive layers and memory structures vertically extending through the alternating stack.
    Type: Grant
    Filed: April 28, 2017
    Date of Patent: April 16, 2019
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Raghuveer S. Makala, Murshed Chowdhury, Keerti Shukla, Tomohisa Abe, Yao-Sheng Lee, James Kai
  • Publication number: 20180151497
    Abstract: A three-dimensional memory device includes driver transistors containing boron doped semiconductor active regions, device contact via structures in physical contact with the boron doped semiconductor active regions, the device contact via structures containing at least one of tantalum, tungsten, and cobalt, and a three-dimensional memory array located over the driver transistors and including an alternating stack of insulating layers and electrically conductive layers and memory structures vertically extending through the alternating stack.
    Type: Application
    Filed: April 28, 2017
    Publication date: May 31, 2018
    Inventors: Raghuveer S. MAKALA, Murshed CHOWDHURY, Keerti SHUKLA, Tomohisa ABE, Yao-Sheng LEE, James KAI
  • Patent number: 9984963
    Abstract: A memory stack structure including a memory film and a vertical semiconductor channel can be formed within each memory opening that extends through a stack including an alternating plurality of insulator layers and sacrificial material layers. After formation of backside recesses through removal of the sacrificial material layers selective to the insulator layers, a backside blocking dielectric layer is formed in the backside recesses and sidewalls of the memory stack structures. A metallic barrier material portion can be formed in each backside recess. A cobalt metal portion can be formed in each backside recess. Each backside recess can be filled with a portion of a backside blocking dielectric layer, a metallic barrier material portion, a cobalt metal portion, and a metallic material portion including a material other than cobalt.
    Type: Grant
    Filed: July 29, 2016
    Date of Patent: May 29, 2018
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Somesh Peri, Rahul Sharangpani, Raghuveer S. Makala, Senaka Kanakamedala, Keerti Shukla
  • Patent number: 9960180
    Abstract: Memory openings can be formed through an alternating stack of insulating layers and sacrificial material layers. Memory stack structures including charge storage elements can be formed in the memory openings. Inter-level charge leakage in a three-dimensional memory device including a charge trapping layer can be minimized by employing a thin continuous charge trapping material layer within each memory opening. After removal of the sacrificial material layers and formation of backside recesses, discrete charge trapping material portions can be formed by selective growth of a charge trapping material from physically exposed surfaces of each thin continuous charge trapping material layer. The discrete charge trapping material portions can function as primary charge storage regions, and inter-level charge leakage can be minimized by the small thickness of the thin continuous charge trapping material layer.
    Type: Grant
    Filed: March 27, 2017
    Date of Patent: May 1, 2018
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Fei Zhou, Raghuveer Makala, Rahul Sharangpani, Keerti Shukla, Yanli Zhang, Peng Zhang
  • Patent number: 9875929
    Abstract: A memory opening is formed through an alternating stack of sacrificial material layers and electrically conductive layers located over a substrate. Discrete annular dielectric metal oxide structures are formed on sidewalls of the electrically conductive layers around the memory opening. After forming memory stack structures including the annular dielectric metal oxide structures in the memory opening, lateral recesses are formed by removing the sacrificial material layers selective to the electrically conductive layers. Sacrificial material layers in the memory stack structure are etched at levels of the lateral recesses to form discrete annular structures at each level of the electrically conductive layers, each of which includes, from inside to outside, a respective annular charge storage structure, and a respective blocking dielectric comprising an annular dielectric metal oxide structure.
    Type: Grant
    Filed: January 23, 2017
    Date of Patent: January 23, 2018
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Keerti Shukla, Raghuveer S. Makala, Rahul Sharangpani, Fei Zhou
  • Publication number: 20170373197
    Abstract: Memory stack structures are formed through an alternating stack of insulating layers and sacrificial material layers. Backside recesses are formed by removal of the sacrificial material layers selective to the insulating layers and the memory stack structures. An electrically conductive, amorphous barrier layer can be formed prior to formation of a metal fill material layer to provide a diffusion barrier that reduces fluorine diffusion between the metal fill material layer and memory films of memory stack structures. The electrically conductive, amorphous barrier layer can be an oxygen-containing titanium compound or a ternary transition metal nitride.
    Type: Application
    Filed: October 12, 2016
    Publication date: December 28, 2017
    Inventors: Rahul Sharangpani, Raghuveer S. Makala, Keerti Shukla, Fei Zhou, Somesh Peri
  • Publication number: 20170373079
    Abstract: Memory stack structures are formed through an alternating stack of insulating layers and sacrificial material layers. Backside recesses are formed by removal of the sacrificial material layers selective to the insulating layers and the memory stack structures. A barrier layer stack including a crystalline electrically conductive barrier layer and an amorphous barrier layer is formed in the backside recesses prior to formation of a metal fill material layer.
    Type: Application
    Filed: April 10, 2017
    Publication date: December 28, 2017
    Inventors: Rahul SHARANGPANI, Fumitaka AMANO, Raghuveer S. MAKALA, Fei ZHOU, Keerti SHUKLA
  • Patent number: 9812463
    Abstract: A memory opening can be formed through an alternating stack of insulating layers and sacrificial material layers provided over a substrate. Annular etch stop material portions are provided at each level of the sacrificial material layers around the memory opening. The annular etch stop material portions can be formed by conversion of surface portions of the sacrificial material layers into dielectric material portion, or by recessing the sacrificial material layers around the memory opening and filling indentations around the memory opening. After formation of a memory stack structure, the sacrificial material layers are removed from the backside. The annular etch stop material portions are at least partially converted to form charge trapping material portions. Vertical isolation of the charge trapping material portions among one another around the memory stack structure minimizes leakage between the charge trapping material portions located at different word line levels.
    Type: Grant
    Filed: August 29, 2016
    Date of Patent: November 7, 2017
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Rahul Sharangpani, Raghuveer S. Makala, Senaka Kanakamedala, Fei Zhou, Somesh Peri, Masanori Tsutsumi, Keerti Shukla, Yusuke Ikawa, Kiyohiko Sakakibara, Eisuke Takii
  • Patent number: 9793139
    Abstract: A silicon-containing nucleation layer can be employed to provide a self-aligned template for selective deposition of tungsten within backside recesses during formation of a three-dimensional memory device. The silicon-containing nucleation layer may remain as a silicon layer, converted into a tungsten silicide layer, or replaced with a tungsten nucleation layer. Tungsten deposition can proceed only on the surface of the silicon-containing nucleation layer or a layer derived therefrom in a subsequent tungsten deposition process.
    Type: Grant
    Filed: March 31, 2016
    Date of Patent: October 17, 2017
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Rahul Sharangpani, Keerti Shukla, Raghuveer S. Makala, Somesh Peri, Yao-Sheng Lee
  • Publication number: 20170278859
    Abstract: A memory opening can be formed through an alternating stack of insulating layers and sacrificial material layers provided over a substrate. Annular etch stop material portions are provided at each level of the sacrificial material layers around the memory opening. The annular etch stop material portions can be formed by conversion of surface portions of the sacrificial material layers into dielectric material portion, or by recessing the sacrificial material layers around the memory opening and filling indentations around the memory opening. After formation of a memory stack structure, the sacrificial material layers are removed from the backside. The annular etch stop material portions are at least partially converted to form charge trapping material portions. Vertical isolation of the charge trapping material portions among one another around the memory stack structure minimizes leakage between the charge trapping material portions located at different word line levels.
    Type: Application
    Filed: August 29, 2016
    Publication date: September 28, 2017
    Inventors: Rahul SHARANGPANI, Raghuveer S. MAKALA, Senaka KANAKAMEDALA, Fei ZHOU, Somesh PERI, Masanori TSUTSUMI, Keerti SHUKLA, Yusuke IKAWA, Kiyohiko SAKAKIBARA, Eisuke TAKII
  • Publication number: 20170125538
    Abstract: A silicon-containing nucleation layer can be employed to provide a self-aligned template for selective deposition of tungsten within backside recesses during formation of a three-dimensional memory device. The silicon-containing nucleation layer may remain as a silicon layer, converted into a tungsten silicide layer, or replaced with a tungsten nucleation layer. Tungsten deposition can proceed only on the surface of the silicon-containing nucleation layer or a layer derived therefrom in a subsequent tungsten deposition process.
    Type: Application
    Filed: March 31, 2016
    Publication date: May 4, 2017
    Inventors: Rahul SHARANGPANI, Keerti SHUKLA, Raghuveer S. MAKALA, Somesh PERI, Yao-Sheng LEE
  • Publication number: 20160351497
    Abstract: A memory stack structure including a memory film and a vertical semiconductor channel can be formed within each memory opening that extends through a stack including an alternating plurality of insulator layers and sacrificial material layers. After formation of backside recesses through removal of the sacrificial material layers selective to the insulator layers, a backside blocking dielectric layer is formed in the backside recesses and sidewalls of the memory stack structures. A metallic barrier material portion can be formed in each backside recess. A cobalt metal portion can be formed in each backside recess. Each backside recess can be filled with a portion of a backside blocking dielectric layer, a metallic barrier material portion, a cobalt metal portion, and a metallic material portion including a material other than cobalt.
    Type: Application
    Filed: July 29, 2016
    Publication date: December 1, 2016
    Inventors: Somesh Peri, Rahul Sharangpani, Raghuveer S. Makala, Senaka Kanakamedala, Keerti Shukla