Patents by Inventor Rahul Sharangpani

Rahul Sharangpani 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: 10741572
    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 insulating layers and sacrificial material layers. After formation of backside recesses through removal of the sacrificial material layers selective to the insulating layers, a backside blocking dielectric layer may be 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 metallic material portion is formed on the metallic barrier material portion. Subsequently, a metal portion comprising a material selected from cobalt and ruthenium is formed directly on a sidewall of the metallic barrier material portion and a sidewall of the metallic material portion and an overlying insulating surface and an underlying insulating surface.
    Type: Grant
    Filed: June 15, 2017
    Date of Patent: August 11, 2020
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Rahul Sharangpani, Raghuveer Makala, Yanli Zhang, Yao-Sheng Lee
  • Publication number: 20200243500
    Abstract: A support die includes complementary metal-oxide-semiconductor (CMOS) devices, front support-die bonding pads electrically connected to a first subset of the peripheral circuitry, and backside bonding structures electrically connected to a second subset of the peripheral circuitry. A first memory die including a first three-dimensional array of memory elements is bonded to the support die. First memory-die bonding pads of the first memory die are bonded to the front support-die bonding pads. A second memory die including a second three-dimensional array of memory elements is bonded to the support die. Second memory-die bonding pads of the second memory die are bonded to the backside bonding structures.
    Type: Application
    Filed: April 14, 2020
    Publication date: July 30, 2020
    Inventors: Fei Zhou, Raghuveer S. Makala, Adarsh Rajashekhar, Rahul Sharangpani
  • Publication number: 20200194446
    Abstract: Three-dimensional memory devices include structures that induce a vertical tensile stress in vertical semiconductor channels to enhance charge carrier mobility. Vertical tensile stress may be induced by a laterally compressive stress applied by stressor pillar structure. The stressor pillar structures can include a stressor material such as a dielectric metal oxide material, silicon nitride, thermal silicon oxide or a semiconductor material having a greater lattice constant than that of the channel. Vertical tensile stress may be induced by a compressive stress applied by electrically conductive layers that laterally surround the vertical semiconductor channel, or by a stress memorization technique that captures a compressive stress from sacrificial material layers. Vertical tensile stress can be generated by a source-level pinning layer that prevents vertical expansion of the vertical semiconductor channel.
    Type: Application
    Filed: December 17, 2018
    Publication date: June 18, 2020
    Inventors: Akio NISHIDA, Toshikazu IIZUKA, Rahul SHARANGPANI, Raghuveer S. MAKALA, Adarsh RAJASHEKHAR, Fei ZHOU, Srikanth RANGANATHAN
  • Publication number: 20200194445
    Abstract: Three-dimensional memory devices include structures that induce a vertical tensile stress in vertical semiconductor channels to enhance charge carrier mobility. Vertical tensile stress may be induced by a laterally compressive stress applied by stressor pillar structure. The stressor pillar structures can include a stressor material such as a dielectric metal oxide material, silicon nitride, thermal silicon oxide or a semiconductor material having a greater lattice constant than that of the channel. Vertical tensile stress may be induced by a compressive stress applied by electrically conductive layers that laterally surround the vertical semiconductor channel, or by a stress memorization technique that captures a compressive stress from sacrificial material layers. Vertical tensile stress can be generated by a source-level pinning layer that prevents vertical expansion of the vertical semiconductor channel.
    Type: Application
    Filed: December 17, 2018
    Publication date: June 18, 2020
    Inventors: Rahul SHARANGPANI, Raghuveer S. MAKALA, Adarsh RAJASHEKHAR, Fei ZHOU, Srikanth RANGANATHAN, Akio NISHIDA, Toshikazu IIZUKA
  • Publication number: 20200168619
    Abstract: In-process source-level material layers including a source-level sacrificial layer are formed over a substrate. An alternating stack of insulating layers and sacrificial material layers is formed over the in-process source-level material layers. A memory opening is formed through the alternating stack, and is filled with a memory film and a sacrificial opening fill structure. The source-level sacrificial layer is replaced with a source contact layer including a doped polycrystalline semiconductor material. The source contact layer can be formed by diffusing a metal in a metallic catalyst material through a semiconductor fill material layer that fills a source cavity formed by removal of the source-level sacrificial layer. The sacrificial opening fill structure is replaced with a vertical semiconductor channel, which can be formed with large grains due to large crystal sizes in the source contact layer. The sacrificial material layers are replaced with electrically conductive layers.
    Type: Application
    Filed: November 26, 2018
    Publication date: May 28, 2020
    Inventors: Fei ZHOU, Adarsh RAJASHEKHAR, Rahul SHARANGPANI, Raghuveer S. MAKALA
  • Patent number: 10665581
    Abstract: A support die includes complementary metal-oxide-semiconductor (CMOS) devices, front support-die bonding pads electrically connected to a first subset of the peripheral circuitry, and backside bonding structures electrically connected to a second subset of the peripheral circuitry. A first memory die including a first three-dimensional array of memory elements is bonded to the support die. First memory-die bonding pads of the first memory die are bonded to the front support-die bonding pads. A second memory die including a second three-dimensional array of memory elements is bonded to the support die. Second memory-die bonding pads of the second memory die are bonded to the backside bonding structures.
    Type: Grant
    Filed: January 23, 2019
    Date of Patent: May 26, 2020
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Fei Zhou, Raghuveer S. Makala, Adarsh Rajashekhar, Rahul Sharangpani
  • Publication number: 20200152655
    Abstract: A vertical repetition of a unit layer stack including an insulating layer, a sacrificial material layer, and a nucleation promoter layer is formed over a substrate. Memory stack structures are formed through the vertical repetition. Each of the memory stack structures comprises a memory film and a vertical semiconductor channel. Backside recesses are formed by removing the sacrificial material layers selective to the insulating layers and the nucleation promoter layers within the vertical repetition. Electrically conductive layers are formed in the backside recesses by selectively growing a metallic material from physically exposed surfaces of the nucleation promoter layers while suppressing growth of the metallic material from physically exposed surfaces of the insulating layers.
    Type: Application
    Filed: November 8, 2018
    Publication date: May 14, 2020
    Inventors: Rahul SHARANGPANI, Fei ZHOU, Raghuveer S. MAKALA, Adarsh RAJASHEKHAR
  • Patent number: 10651196
    Abstract: A vertical repetition of a unit layer stack including an insulating layer, a sacrificial material layer, and a nucleation promoter layer is formed over a substrate. Memory stack structures are formed through the vertical repetition. Each of the memory stack structures comprises a memory film and a vertical semiconductor channel. Backside recesses are formed by removing the sacrificial material layers selective to the insulating layers and the nucleation promoter layers within the vertical repetition. Electrically conductive layers are formed in the backside recesses by selectively growing a metallic material from physically exposed surfaces of the nucleation promoter layers while suppressing growth of the metallic material from physically exposed surfaces of the insulating layers.
    Type: Grant
    Filed: November 8, 2018
    Date of Patent: May 12, 2020
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Rahul Sharangpani, Fei Zhou, Raghuveer S. Makala, Adarsh Rajashekhar
  • Patent number: 10622368
    Abstract: Azimuthally-split metal-semiconductor alloy floating gate electrodes can be formed by providing an alternating stack of insulating layers and spacer material layers, forming a dielectric separator structure extending through the alternating stack, and forming memory openings that divides the dielectric separator structure into a plurality of dielectric separator structures. The spacer material layers are formed as, or are replaced with, electrically conductive layers, which are laterally recessed selective to the insulating layers and the plurality of dielectric separator structures to form a pair of lateral cavities at each level of the electrically conductive layers in each memory opening. After formation of a blocking dielectric layer, a pair of physically disjoined metal-semiconductor alloy portions are formed in each pair of lateral cavities as floating gate electrodes. A tunneling dielectric layer and a semiconductor channel layer is subsequently formed in each memory opening.
    Type: Grant
    Filed: August 3, 2016
    Date of Patent: April 14, 2020
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Senaka Kanakamedala, Raghuveer S. Makala, Rahul Sharangpani, Somesh Peri, Yao-Sheng Lee, James Kai
  • Patent number: 10615123
    Abstract: A three-dimensional memory device includes an alternating stack of insulating layers and electrically conductive layers located over a substrate and memory stack structures extending through the alternating stack. Each of the electrically conductive layers includes a stack of a compositionally graded diffusion barrier and a metal fill material portion, and the compositionally graded diffusion barrier includes a substantially amorphous region contacting the interface between the compositionally graded diffusion barrier and a substantially crystalline region that is spaced from the interface by the amorphous region. The substantially crystalline region effectively blocks atomic diffusion, and the amorphous region induces formation of large grains during deposition of the metal fill material portions.
    Type: Grant
    Filed: June 27, 2018
    Date of Patent: April 7, 2020
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Tatsuya Hinoue, Tomoyuki Obu, Tomohiro Uno, Yusuke Mukae, Rahul Sharangpani, Raghuveer S. Makala, Fei Zhou, Adarsh Rajashekhar
  • Publication number: 20200105595
    Abstract: A method of forming a memory device includes forming an alternating stack of insulating layers and sacrificial material layers over a substrate forming memory stack structures through the alternating stack, forming a first backside trench and a second backside trench through the alternating stack, forming backside recesses by removing the sacrificial material layers, depositing a backside blocking dielectric layer after formation of the backside recesses, forming a liner that a lesser lateral extent than a lateral distance between the first backside trench and the second backside trench; and selectively growing a metal from surfaces of the liners while either not growing or growing at a lower rate the metal from surfaces of the backside recesses that are not covered by the liners.
    Type: Application
    Filed: November 19, 2019
    Publication date: April 2, 2020
    Inventors: Rahul SHARANGPANI, Raghuveer S. MAKALA, Fei ZHOU, Adarsh RAJASHEKHAR, Senaka Krishna KANAKAMEDALA, Fumitaka AMANO, Genta MIZUNO
  • Patent number: 10529620
    Abstract: A method of forming a memory device includes forming an alternating stack of insulating layers and sacrificial material layers over a substrate forming memory stack structures through the alternating stack, forming a first backside trench and a second backside trench through the alternating stack, forming backside recesses by removing the sacrificial material layers, depositing a backside blocking dielectric layer after formation of the backside recesses, forming a liner that a lesser lateral extent than a lateral distance between the first backside trench and the second backside trench; and selectively growing a metal from surfaces of the liners while either not growing or growing at a lower rate the metal from surfaces of the backside recesses that are not covered by the liners.
    Type: Grant
    Filed: December 4, 2017
    Date of Patent: January 7, 2020
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Rahul Sharangpani, Raghuveer S. Makala, Fei Zhou, Adarsh Rajashekhar, Senaka Krishna Kanakamedala, Fumitaka Amano, Genta Mizuno
  • Publication number: 20190371803
    Abstract: Azimuthally-split metal-semiconductor alloy floating gate electrodes can be formed by providing an alternating stack of insulating layers and spacer material layers, forming a dielectric separator structure extending through the alternating stack, and forming memory openings that divides the dielectric separator structure into a plurality of dielectric separator structures. The spacer material layers are formed as, or are replaced with, electrically conductive layers, which are laterally recessed selective to the insulating layers and the plurality of dielectric separator structures to form a pair of lateral cavities at each level of the electrically conductive layers in each memory opening. After formation of a blocking dielectric layer, a pair of physically disjoined metal-semiconductor alloy portions are formed in each pair of lateral cavities as floating gate electrodes. A tunneling dielectric layer and a semiconductor channel layer is subsequently formed in each memory opening.
    Type: Application
    Filed: August 3, 2016
    Publication date: December 5, 2019
    Inventors: Senaka Kanakamedala, Raghuveer S. Makala, Rahul Sharangpani, Somesh Peri, Yao-Sheng Lee, James Kai
  • Publication number: 20190287982
    Abstract: A three-dimensional memory device includes an alternating stack of insulating layers and electrically conductive layers located over a substrate and memory stack structures extending through the alternating stack. Each of the electrically conductive layers includes a stack of a compositionally graded diffusion barrier and a metal fill material portion, and the compositionally graded diffusion barrier includes a substantially amorphous region contacting the interface between the compositionally graded diffusion barrier and a substantially crystalline region that is spaced from the interface by the amorphous region. The substantially crystalline region effectively blocks atomic diffusion, and the amorphous region induces formation of large grains during deposition of the metal fill material portions.
    Type: Application
    Filed: June 27, 2018
    Publication date: September 19, 2019
    Inventors: Tatsuya HINOUE, Tomoyuki OBU, Tomohiro UNO, Yusuke MUKAE, Rahul SHARANGPANI, Raghuveer S. MAKALA, Fei ZHOU, Adarsh RAJASHEKHAR
  • Publication number: 20190287916
    Abstract: A three-dimensional memory device includes an alternating stack of insulating layers and electrically conductive layers located over a substrate and memory stack structures extending through the alternating stack. Each of the electrically conductive layers includes a stack of a compositionally graded diffusion barrier and a metal fill material portion, and the compositionally graded diffusion barrier includes a substantially amorphous region contacting the interface between the compositionally graded diffusion barrier and a substantially crystalline region that is spaced from the interface by the amorphous region. The substantially crystalline region effectively blocks atomic diffusion, and the amorphous region induces formation of large grains during deposition of the metal fill material portions.
    Type: Application
    Filed: June 27, 2018
    Publication date: September 19, 2019
    Inventors: Rahul SHARANGPANI, Raghuveer S. MAKALA, Fei ZHOU, Adarsh RAJASHEKHAR, Tatsuya HINOUE, Tomoyuki OBU, Tomohiro UNO, Yusuke MUKAE
  • Patent number: 10381409
    Abstract: Alternating stacks of insulating strips and sacrificial material strips are formed over a substrate. A laterally alternating sequence of pillar cavities and pillar structures can be formed within each of the line trenches. A phase change memory cell including a discrete metal portion, a phase change memory material portion, and a selector material portion is formed at each level of the sacrificial material strips at a periphery of each of the pillar cavities. Vertical bit lines are formed in the two-dimensional array of pillar cavities. Remaining portions of the sacrificial material strips are replaced with electrically conductive word line strips. Pathways for providing an isotropic etchant for the sacrificial material strips and a reactant for a conductive material of the electrically conductive word line strips may be provided by a backside trench, or by removing the pillar structures to provide backside openings.
    Type: Grant
    Filed: June 7, 2018
    Date of Patent: August 13, 2019
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Fei Zhou, Raghuveer S. Makala, Christopher J. Petti, Rahul Sharangpani, Adarsh Rajashekhar, Seung-Yeul Yang
  • Patent number: 10381559
    Abstract: Alternating stacks of insulating strips and sacrificial material strips are formed over a substrate. A laterally alternating sequence of pillar cavities and pillar structures can be formed within each of the line trenches. A phase change memory cell including a discrete metal portion, a phase change memory material portion, and a selector material portion is formed at each level of the sacrificial material strips at a periphery of each of the pillar cavities. Vertical bit lines are formed in the two-dimensional array of pillar cavities. Remaining portions of the sacrificial material strips are replaced with electrically conductive word line strips. Pathways for providing an isotropic etchant for the sacrificial material strips and a reactant for a conductive material of the electrically conductive word line strips may be provided by a backside trench, or by removing the pillar structures to provide backside openings.
    Type: Grant
    Filed: June 7, 2018
    Date of Patent: August 13, 2019
    Assignee: SanDisk Technologies LLC
    Inventors: Fei Zhou, Raghuveer S. Makala, Christopher J. Petti, Rahul Sharangpani, Adarsh Rajashekhar, Seung-Yeul Yang
  • Patent number: 10381364
    Abstract: A three-dimensional memory device can be formed by first forming an alternating stack of insulating layers and stack level spacer material layers over a substrate. The stack level spacer material layers can be formed as, or are subsequently replaced with, stack level electrically conductive layers. A bottommost insulating spacer layer is formed with recesses that form grooves that are laterally spaced apart. Drain select level electrically conductive layers are formed over protruding portions and within the grooves of the bottommost insulating spacer layer by anisotropic deposition and isotropic etch back of a conductive material. Additional insulating spacer layers may be formed by anisotropic deposition of an insulating material. Additional drain select level electrically conductive layers can be formed by anisotropic deposition and isotropic etch back of additional conductive material.
    Type: Grant
    Filed: June 20, 2017
    Date of Patent: August 13, 2019
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Fei Zhou, Rahul Sharangpani, Yanli Zhang, Raghuveer S. Makala, Senaka Krishna Kanakamedala
  • 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