Patents by Inventor Adarsh RAJASHEKHAR

Adarsh RAJASHEKHAR 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: 11984395
    Abstract: A semiconductor structure includes semiconductor devices located over a substrate, bit lines electrically connected to the semiconductor devices and having a respective reentrant vertical cross-sectional profile within a vertical plane that is perpendicular to a lengthwise direction along which the bit lines laterally extend, and dielectric portions that are interlaced with the bit lines along a horizontal direction that is perpendicular to the lengthwise direction. The dielectric portions may contain air gaps. A bit-line-contact via structure can be formed on top of a bit line. In some embodiments, dielectric cap strips may be located on top surface of the dielectric portions and may cover peripheral regions of the top surfaces of the bit lines without covering middle regions of the top surfaces of the bit lines.
    Type: Grant
    Filed: September 20, 2021
    Date of Patent: May 14, 2024
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Adarsh Rajashekhar, Raghuveer S. Makala, Rahul Sharangpani, Fei Zhou
  • Patent number: 11973123
    Abstract: A semiconductor structure includes an active region including a source region, a drain region, and a channel region extending between the source region and the drain region, a gate stack, and a gate dielectric layer located between the gate stack and the active region. The gate stack includes an electrically conductive gate electrode and a single crystalline III-nitride ferroelectric plate located between the electrically conductive gate electrode and the gate dielectric layer, and an entirety of the single crystalline III-nitride ferroelectric plate is single crystalline.
    Type: Grant
    Filed: January 18, 2022
    Date of Patent: April 30, 2024
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Adarsh Rajashekhar, Raghuveer S. Makala, Kartik Sondhi
  • Publication number: 20240130137
    Abstract: A semiconductor memory device includes an alternating stack of insulating layers and electrically conductive layers, a memory opening vertically extending through the alternating stack, and a memory opening fill structure located in the memory opening and including a vertical semiconductor channel and a vertical stack of discrete ferroelectric material portions located at levels of the electrically conductive layers. The discrete ferroelectric material portions protrude inward into the memory opening relative to vertical sidewalls of the insulating layers.
    Type: Application
    Filed: August 14, 2023
    Publication date: April 18, 2024
    Inventors: Kartik Sondhi, Raghuveer S. Makala, Adarsh Rajashekhar, Rahul Sharangpani, Fei Zhou
  • Publication number: 20240121960
    Abstract: A memory device includes an alternating stack of insulating layers and electrically conductive layers, a memory opening vertically extending through the alternating stack and having a lateral undulation in a vertical cross-sectional profile such that the memory opening laterally protrudes outward at levels of the electrically conductive layers, and a memory opening fill structure located in the memory opening and including a vertical stack of blocking dielectric material portions located at the levels of the electrically conductive layers, a vertical stack of discrete memory elements located at the levels of the electrically conductive layers and including a respective contoured charge storage material portion, a tunneling dielectric layer overlying the contoured inner sidewalls of the tubular charge storage material portion, and a vertical semiconductor channel.
    Type: Application
    Filed: July 7, 2023
    Publication date: April 11, 2024
    Inventors: Adarsh RAJASHEKHAR, Raghuveer S. MAKALA, Fei ZHOU, Rahul SHARANGPANI, Kartik SONDHI
  • Patent number: 11948902
    Abstract: A bonded assembly includes a first semiconductor die containing a first substrate, first semiconductor devices, and first bonding pads laterally surrounded by a first pad-level dielectric layer. The first pad-level dielectric layer includes at least one first encapsulated airgap located between neighboring pairs of first bonding pads and encapsulated by a first dielectric fill material of the first pad-level dielectric layer. The bonded assembly includes a second semiconductor die containing a second substrate, second semiconductor devices, and second bonding pads laterally surrounded by a second pad-level dielectric layer. Each of the second bonding pads is bonded to a respective one of the first bonding pads.
    Type: Grant
    Filed: July 8, 2021
    Date of Patent: April 2, 2024
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Lin Hou, Peter Rabkin, Adarsh Rajashekhar, Raghuveer S. Makala, Masaaki Higashitani
  • Publication number: 20240064995
    Abstract: A ferroelectric memory device includes an alternating stack of insulating layers and composite layers that are interlaced along a vertical direction, a memory opening vertically extending through the alternating stack, a memory opening fill structure located in the memory opening and including a vertical semiconductor channel and an inner ferroelectric material layer including a first ferroelectric material, and a vertical stack of electrically-non-insulating material portions located between the inner ferroelectric material layer and the composite layers. Each of the composite layers includes a respective electrically conductive layer and a respective outer ferroelectric material layer including a second ferroelectric material, embedding the respective electrically conductive layer, and contacting a respective electrically-non-insulating material portion.
    Type: Application
    Filed: January 30, 2023
    Publication date: February 22, 2024
    Inventors: Adarsh RAJASHEKHAR, Raghuveer S. MAKALA, Kartik SONDHI, Rahul SHARANGPANI, Fei ZHOU
  • Publication number: 20240064991
    Abstract: A semiconductor memory device includes an alternating stack of insulating layers and electrically conductive layers, a memory opening vertically extending through the alternating stack, and a memory opening fill structure located in the memory opening and including a vertical stack of discrete ferroelectric material portions and a vertical semiconductor channel. In one embodiment, the discrete ferroelectric material portions include a ferroelectric alloy material of a first dielectric metal oxide material and a second dielectric metal oxide material. In another embodiment, each of the discrete ferroelectric material portions is oxygen-deficient.
    Type: Application
    Filed: August 19, 2022
    Publication date: February 22, 2024
    Inventors: Kartik SONDHI, Rahul SHARANGPANI, Raghuveer S. MAKALA, Tiffany SANTOS, Fei ZHOU, Joyeeta NAG, Bhagwati PRASAD, Adarsh RAJASHEKHAR
  • Patent number: 11877446
    Abstract: A three-dimensional memory device includes an alternating stack of insulating layers and electrically conductive layers, memory openings vertically extending through the alternating stack, and memory opening fill structures located within the memory openings. Each of the electrically conductive layers includes a metallic fill material layer and a plurality of vertical tubular metallic liners laterally surrounding a respective one of the memory opening fill structures and located between the metallic fill material layer and a respective one of the memory opening fill structures. The tubular metallic liners may be formed by selective metal or metal oxide deposition, or by conversion of surface portions of the metallic fill material layers into metallic compound material portions by nitridation, oxidation, or incorporation of boron atoms.
    Type: Grant
    Filed: June 11, 2021
    Date of Patent: January 16, 2024
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Rahul Sharangpani, Raghuveer S. Makala, Fei Zhou, Adarsh Rajashekhar
  • Publication number: 20240008281
    Abstract: A ferroelectric memory device includes an alternating stack of insulating layers and electrically conductive layers, a memory opening extending vertically through the alternating stack and including laterally-protruding portions at levels of the electrically conductive layers, and a memory opening fill structure located in the memory opening and containing a vertical semiconductor channel and a vertical stack of discrete ferroelectric memory structures located in the laterally-protruding portions of the memory opening. Each of the ferroelectric memory structures includes crystalline ferroelectric material portion and a crystalline template material portion located between a respective electrically conductive layer of the electrically conductive layers and the crystalline ferroelectric material portion.
    Type: Application
    Filed: June 29, 2022
    Publication date: January 4, 2024
    Inventors: Kartik SONDHI, Adarsh RAJASHEKHAR, Fei ZHOU, Raghuveer S. MAKALA
  • Publication number: 20230389317
    Abstract: A semiconductor structure includes an alternating stack of first insulating layers and first electrically conductive layers, the first alternating stack having first stepped surfaces, at least one first metal oxide etch stop layer overlying and contacting the first stepped surfaces, a first stepped dielectric material portion overlying the at least one first metal oxide etch stop layer and the first stepped surfaces, a memory opening vertically extending through the first alternating stack, a memory opening fill structure located in the memory opening and containing a memory film and a vertical semiconductor channel, and an electrically conductive layer contact via structure vertically extending through the first stepped dielectric material portion and the at least one first metal oxide etch stop layer, and contacting a respective one of the first electrically conductive layers.
    Type: Application
    Filed: August 14, 2023
    Publication date: November 30, 2023
    Inventors: Mitsuhiro Togo, Fumiaki Toyama, Adarsh RAJASHEKHAR
  • Publication number: 20230352401
    Abstract: A structure includes semiconductor devices located over a substrate, a first interconnect-level dielectric layer located above the semiconductor devices, a first metal structure embedded in the first interconnect-level dielectric layer, where a top surface of the first metal structure and a top surface of the first interconnect-level dielectric layer are located in a same first horizontal plane, a spacer dielectric material layer having a contoured top surface and a planar bottom surface located in the first horizontal plane on the top surface of the first interconnect-level dielectric layer, at least one opening located in the spacer dielectric material layer, a metal cap structure located in the at least one opening and having a bottom surface in contact with at least a portion of the top surface of the first metal structure, and a second metal structure located on a top surface of the metal cap structure.
    Type: Application
    Filed: July 5, 2023
    Publication date: November 2, 2023
    Inventors: Rahul SHARANGPANI, Raghuveer S. MAKALA, Adarsh RAJASHEKHAR, Kartik SONDHI
  • Publication number: 20230345719
    Abstract: An alternating stack of insulating layers and electrically conductive layers is formed over a substrate, and a memory opening vertically extends through the alternating stack. The memory opening is laterally expanded at levels of the insulating layers. At least one blocking dielectric layer is formed in the memory opening. A first vertical stack of discrete charge storage elements is formed at levels of the electrically conductive layers. A second vertical stack of discrete dielectric material portions is formed at the levels of the insulating layers. A tunneling dielectric layer is formed over the first vertical stack and the second vertical stack. A vertical semiconductor channel is formed on the tunneling dielectric layer.
    Type: Application
    Filed: April 20, 2022
    Publication date: October 26, 2023
    Inventors: Kartik SONDHI, Adarsh RAJASHEKHAR, Rahul SHARANGPANI, Raghuveer S. MAKALA
  • Publication number: 20230301077
    Abstract: A semiconductor structure includes a doped single crystalline semiconductor material layer, a metal or metal alloy source contact layer located over a back side of the doped single crystalline semiconductor material layer, a dielectric isolation layer located over a front side of the doped single crystalline semiconductor material layer, an alternating stack of insulating layers and electrically conductive layers located over the dielectric isolation layer, a memory opening vertically extending through the alternating stack and the dielectric isolation layer and at least partially through the doped single crystalline semiconductor material layer, a memory film and a vertical semiconductor channel located within the memory opening, such that the vertical semiconductor channel vertically extends through the dielectric isolation layer and into the doped single crystalline semiconductor material layer, and a single crystalline semiconductor pedestal contacting the doped single crystalline semiconductor material l
    Type: Application
    Filed: March 17, 2022
    Publication date: September 21, 2023
    Inventors: Adarsh RAJASHEKHAR, Raghuveer S. MAKALA, Masanori TSUTSUMI, Fei ZHOU
  • Publication number: 20230246084
    Abstract: A semiconductor structure includes an alternating stack of insulating layers and electrically conductive layers, a memory opening vertically extending through the alternating stack, and a memory opening fill structure located in the memory opening and including a vertical semiconductor channel, a memory film in contact with the vertical semiconductor channel, and a vertical stack of tubular dielectric spacers laterally surrounding the memory film. The tubular dielectric spacers may include tubular graded silicon oxynitride portions having a composition gradient such that an atomic concentration of nitrogen decreases with a lateral distance from an outer sidewall of the memory film, or may include tubular composite dielectric spacers including a respective tubular silicon oxide spacer and a respective tubular dielectric metal oxide spacer. Each of the electrically conductive layers has a hammerhead-shaped vertical cross-sectional profile.
    Type: Application
    Filed: January 28, 2022
    Publication date: August 3, 2023
    Inventors: Adarsh RAJASHEKHAR, Raghuveer S. MAKALA, Koichi MATSUNO
  • Publication number: 20230231029
    Abstract: A semiconductor structure includes an active region including a source region, a drain region, and a channel region extending between the source region and the drain region, a gate stack, and a gate dielectric layer located between the gate stack and the active region. The gate stack includes an electrically conductive gate electrode and a single crystalline III-nitride ferroelectric plate located between the electrically conductive gate electrode and the gate dielectric layer, and an entirety of the single crystalline III-nitride ferroelectric plate is single crystalline.
    Type: Application
    Filed: January 18, 2022
    Publication date: July 20, 2023
    Inventors: Adarsh RAJASHEKHAR, Raghuveer S. MAKALA, Kartik SONDHI
  • Publication number: 20230232634
    Abstract: A semiconductor structure includes an active region including a source region, a drain region, and a channel region extending between the source region and the drain region, a gate stack, and a gate dielectric layer located between the gate stack and the active region. The gate stack includes an electrically conductive gate electrode and a single crystalline III-nitride ferroelectric plate located between the electrically conductive gate electrode and the gate dielectric layer, and an entirety of the single crystalline III-nitride ferroelectric plate is single crystalline.
    Type: Application
    Filed: January 18, 2022
    Publication date: July 20, 2023
    Inventors: Adarsh RAJASHEKHAR, Raghuveer S. MAKALA, Kartik SONDHI
  • Publication number: 20230178425
    Abstract: A method of forming a structure includes forming an alternating stack of first material layers and second material layers over a substrate, forming a first etch mask material layer, forming a first cladding liner, and forming a via opening through the alternating stack by performing an anisotropic etch process that employs a combination of at least the first cladding liner and the first etch mask material layer as a composite etch mask structure.
    Type: Application
    Filed: January 9, 2023
    Publication date: June 8, 2023
    Inventors: Roshan Jayakhar TIRUKKONDA, Bing ZHOU, Rahul SHARANGPANI, Raghuveer S. MAKALA, Senaka KANAKAMEDALA, Adarsh RAJASHEKHAR
  • Publication number: 20230157013
    Abstract: A three-dimensional memory device includes an alternating stack of insulating layers and electrically conductive layers located over a substrate, memory stack structures vertically extending through the alternating stack, etch stop plates located in the staircase region, laterally and vertically spaced apart among one another, and overlying an end portion of a respective one of the electrically conductive layers, and contact via structures located in a staircase region, vertically extending through a respective one of the etch stop plates, and contacting a respective one of the electrically conductive layers.
    Type: Application
    Filed: November 12, 2021
    Publication date: May 18, 2023
    Inventors: Adarsh RAJASHEKHAR, Raghuveer S. MAKALA, Fei ZHOU
  • Publication number: 20230128682
    Abstract: A memory device includes an alternating stack of insulating layers and electrically conductive layers, a memory opening vertically extending through the alternating stack, and a memory opening fill structure located in the memory opening and including a vertical semiconductor channel and a memory film. The memory film includes a memory material layer having a straight inner cylindrical sidewall that vertically extends through a plurality of electrically conductive layers within the alternating stack without lateral undulation and a laterally-undulating outer sidewall having outward lateral protrusions at levels of the plurality of electrically conductive layers.
    Type: Application
    Filed: December 22, 2022
    Publication date: April 27, 2023
    Inventors: Kartik SONDHI, Raghuveer S. MAKALA, Adarsh RAJASHEKHAR, Rahul SHARANGPANI, Fei ZHOU
  • Patent number: 11631695
    Abstract: A three-dimensional memory device includes an alternating stack of insulating layers and electrically conductive layers located over a substrate. Each electrically conductive layer within a subset of the electrically conductive layers includes a respective first metal layer containing an elemental metal and a respective first metal silicide layer containing a metal silicide of the elemental metal. Memory openings vertically extend through the alternating stack. Memory opening fill structures located within the memory openings can include a respective memory film and a respective vertical semiconductor channel.
    Type: Grant
    Filed: October 30, 2020
    Date of Patent: April 18, 2023
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Rahul Sharangpani, Raghuveer S. Makala, Fei Zhou, Adarsh Rajashekhar