Patents by Inventor Tomohiko Kitajima

Tomohiko Kitajima 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: 11574924
    Abstract: Embodiments of the present disclosure provide an apparatus and methods for forming stair-like structures with accurate profiles and dimension control for manufacturing three dimensional (3D) stacked memory cell semiconductor devices. In one embodiment, a memory cell device includes a film stack comprising alternating pairs of dielectric layers and conductive structures horizontally formed on a substrate, and an opening formed in the film stack, wherein the opening is filled with a metal dielectric layer, a multi-layer structure and a center filling layer, wherein the metal dielectric layer in the opening is interfaced with the conductive structure.
    Type: Grant
    Filed: March 26, 2021
    Date of Patent: February 7, 2023
    Assignee: Applied Materials, Inc.
    Inventors: Changseok Kang, Tomohiko Kitajima
  • Publication number: 20230012819
    Abstract: Three-dimensional dynamic random-access memory (3D DRAM) structures and methods of formation of same are provided herein. In some embodiments, a 3D DRAM stack can include alternating silicon (Si) layers and silicon germanium (SiGe) layers. Each of the Si layers may have a height greater than a height of each of the SiGe layers. Methods and systems for formation of such structures are further provided.
    Type: Application
    Filed: July 8, 2022
    Publication date: January 19, 2023
    Inventors: John Byron Tolle, Tomohiko Kitajima, Thomas John Kirschenheiter, Patricia M. Liu, Zuoming Zhu, Joe Margetis, Fredrick David Fishburn, Abdul Wahab Mohammed, Gill Yong Lee
  • Patent number: 11545504
    Abstract: Methods and apparatus for forming a plurality of nonvolatile memory cells are provided herein. In some embodiments, the method, for example, includes forming a plurality of nonvolatile memory cells, comprising forming, on a substrate, a stack of alternating layers of metal including a first layer of metal and a second layer of metal different from the first layer of metal; removing the first layer of metal to form spaces between the alternating layers of the second layer of metal; and one of depositing a first layer of material to partially fill the spaces to leave air gaps therein or depositing a second layer of material to fill the spaces.
    Type: Grant
    Filed: April 12, 2021
    Date of Patent: January 3, 2023
    Assignee: APPLIED MATERIALS, INC.
    Inventors: Takehito Koshizawa, Mukund Srinivasan, Tomohiko Kitajima, Chang Seok Kang, Sung-Kwan Kang, Gill Y. Lee, Susmit Singha Roy
  • Patent number: 11515170
    Abstract: Methods of etching film stacks to form gaps of uniform width are described. A film stack is etched through a hardmask. A conformal liner is deposited in the gap. The bottom of the liner is removed. The film stack is selectively etched relative to the liner. The liner is removed. The method may be repeated to a predetermined depth.
    Type: Grant
    Filed: December 30, 2020
    Date of Patent: November 29, 2022
    Assignee: APPLIED MATERIALS, INC.
    Inventors: Shishi Jiang, Pramit Manna, Bo Qi, Abhijit Basu Mallick, Rui Cheng, Tomohiko Kitajima, Harry S. Whitesell, Huiyuan Wang
  • Publication number: 20220367560
    Abstract: Memory devices and methods of manufacturing memory devices are provided. The device and methods described decrease the resistivity of word lines by forming word lines comprising low resistivity materials. The low resistivity material has a resistivity in a range of from 5 ??cm to 100 ??cm. Low resistivity materials may be formed by recessing the word line and selectively growing the low resistivity materials in the recessed portion of the word line. Alternatively, low resistivity materials may be formed by depositing a metal layer and silicidating the metal in the word line region and in the common source line region.
    Type: Application
    Filed: May 11, 2022
    Publication date: November 17, 2022
    Applicant: Applied Materials, Inc.
    Inventors: Chang Seok Kang, Tomohiko Kitajima, Gill Yong Lee
  • Publication number: 20220319601
    Abstract: Described is a memory string including at least one select gate for drain (SGD) transistor and at least one memory transistor in a vertical hole extending through a memory stack on a substrate. The memory stack comprises alternating word lines and dielectric material. There is at least one select-gate-for-drain (SGD) transistor in a first vertical hole extending through the memory stack, the select-gate-for-drain (SGD) transistor comprising a first gate material. At least one memory transistor is in a second vertical hole extending through the memory stack, the at least one memory transistor comprising a second gate material different from the first gate material.
    Type: Application
    Filed: March 28, 2022
    Publication date: October 6, 2022
    Applicant: Applied Materials, Inc.
    Inventors: Chang Seok Kang, Tomohiko Kitajima, Gill Yong Lee, Qian Fu, Sung-Kwan Kang, Takehito Koshizawa, Fredrick Fishburn
  • Publication number: 20220285362
    Abstract: Methods for forming three-dimensional dynamic random-access memory (3D DRAM) structures that leverage a grid pattern of high aspect ratio holes to form subsequent features of the 3D DRAM. The method may include depositing alternating layers of crystalline silicon (c-Si) and crystalline silicon germanium (c-SiGe) using an heteroepitaxy process onto a substrate and HAR etching of a pattern of holes into the substrate. The holes configured to provide chemistry access to laterally etch or deposit materials to form 3D DRAM features without requiring subsequent HAR etching of holes to form the 3D DRAM features.
    Type: Application
    Filed: February 17, 2022
    Publication date: September 8, 2022
    Inventors: Fredrick David FISHBURN, Arvind KUMAR, Sony VARGHESE, Chang Seok KANG, Sung-Kwan KANG, Tomohiko KITAJIMA
  • Patent number: 11430801
    Abstract: Methods and apparatus for forming a plurality of nonvolatile memory cells are provided herein. In some embodiments, the method, for example, includes forming a plurality of nonvolatile memory cells, comprising forming, on a substrate, a stack of alternating layers of metal including a first layer of metal and a second layer of metal different from the first layer of metal; removing the first layer of metal to form spaces between the alternating layers of the second layer of metal; and one of depositing a first layer of material to partially fill the spaces to leave air gaps therein or depositing a second layer of material to fill the spaces.
    Type: Grant
    Filed: April 12, 2021
    Date of Patent: August 30, 2022
    Assignee: APPLIED MATERIALS, INC.
    Inventors: Takehito Koshizawa, Mukund Srinivasan, Tomohiko Kitajima, Chang Seok Kang, Sung-Kwan Kang, Gill Y. Lee, Susmit Singha Roy
  • Publication number: 20220262619
    Abstract: Methods of manufacturing memory devices are provided. The methods improve the quality of a selectively deposited silicon-containing dielectric layer. The method comprises selectively depositing a silicon-containing dielectric layer in a recessed region of a film stack. The selectively deposited silicon-containing dielectric layer is then exposed to a high-density plasma and annealed at a temperature greater than 800 ° C. to provide a silicon-containing dielectric film having a wet etch rate of less than 4 ?/min.
    Type: Application
    Filed: February 9, 2022
    Publication date: August 18, 2022
    Applicant: Applied Materials, Inc.
    Inventors: Ning Li, Shuaidl Zhang, Mihaela A. Balseanu, Qi Gao, Rajesh Prasad, Tomohiko Kitajima, Chang Seok Kang, Deven Matthew Raj Mittal, Kyu-Ha Shim
  • Publication number: 20220108728
    Abstract: Memory devices are described. The memory devices include a plurality of bit lines extending through a stack of alternating memory layers and dielectric layers. Each of the memory layers comprises a single crystalline-like silicon layer and includes a first word line, a second word line, a first capacitor, and a second capacitor. Methods of forming stacked memory devices are also described.
    Type: Application
    Filed: December 15, 2021
    Publication date: April 7, 2022
    Applicant: Applied Materials, Inc.
    Inventors: Chang Seok Kang, Tomohiko Kitajima, Gill Yong Lee, Sanjay Natarajan, Sung-Kwan Kang, Lequn Liu
  • Patent number: 11295786
    Abstract: Memory devices are described. The memory devices include a plurality of bit lines extending through a stack of alternating memory layers and dielectric layers. Each of the memory layers comprises a single crystalline-like silicon layer and includes a first word line, a second word line, a first capacitor, and a second capacitor. Methods of forming stacked memory devices are also described.
    Type: Grant
    Filed: February 3, 2020
    Date of Patent: April 5, 2022
    Assignee: Applied Materials, Inc.
    Inventors: Chang Seok Kang, Tomohiko Kitajima, Gill Yong Lee, Sanjay Natarajan, Sung-Kwan Kang, Lequn Liu
  • Publication number: 20220059555
    Abstract: Described is a memory string including at least one select gate for drain (SGD) transistor and at least one memory transistor in a vertical hole extending through a memory stack on a substrate. The memory stack comprises alternating non-replacement word lines and replacement insulators. A filled slit extends through the memory stack, and there are at least two select gate for drain (SGD) isolation regions in the memory stack adjacent the filled slit. A select-gate-for-drain (SGD) cut is patterned into the top few pairs of alternating layers in the memory stacks. Through the cut opening, the sacrificial layer of the memory stacks is removed, and an insulator layer is used to fill the opening.
    Type: Application
    Filed: August 11, 2021
    Publication date: February 24, 2022
    Applicant: Applied Material, Inc.
    Inventors: Chang Seok Kang, Tomohiko Kitajima
  • Publication number: 20220005810
    Abstract: Described are memory devices having stacked DRAM cells, resulting in an increase in DRAM cell bit-density. The area of a unit cell is composed of a capacitor, a cell transistor, an isolation region and a connection region, where every capacitor and active region for the cell capacitor is electrically isolated. The memory cells have supporting bars. Methods of forming a memory device are described. The methods include patterning the isolation region with supporting bars, removing non-insulator layers after isolation region patterning, and filling the opened region with an insulator.
    Type: Application
    Filed: June 22, 2021
    Publication date: January 6, 2022
    Applicant: Applied Materials, Inc.
    Inventors: Chang Seok Kang, Tomohiko Kitajima
  • Publication number: 20210399011
    Abstract: Described is selective deposition of a silicon nitride (SiN) trap layer to form a memory device. A sacrificial layer is used for selective deposition in order to permit selective trap deposition. The trap layer is formed by deposition of a mold including a sacrificial layer, memory hole (MH) patterning, sacrificial layer recess from MH side, forming a deposition-enabling layer (DEL) on a side of the recess, and selective deposition of trap layer. After removing the sacrificial layer from a slit pattern opening, the deposition-enabling layer (DEL) is converted into an oxide to be used as blocking oxide.
    Type: Application
    Filed: June 14, 2021
    Publication date: December 23, 2021
    Applicant: Applied Materials, Inc.
    Inventors: Chang Seok Kang, Tomohiko Kitajima, Mihaela A. Balseanu
  • Patent number: 11189635
    Abstract: Methods of manufacturing memory devices are provided. The methods decrease the thickness of the first layers and increase the thickness of the second layers. Semiconductor devices are described having a film stack comprising alternating nitride and second layers in a first portion of the device, the alternating nitride and second layers of the film stack having a nitride:oxide thickness ratio (Nf:Of); and a memory stack comprising alternating word line and second layers in a second portion of the device, the alternating word line and second layers of the memory stack having a word line:oxide thickness ratio (Wm:Om), wherein 0.1(Wm:Om)<Nf:Of<0.95(Wm:Om).
    Type: Grant
    Filed: March 30, 2020
    Date of Patent: November 30, 2021
    Assignee: APPLIED MATERIALS, INC.
    Inventors: Chang Seok Kang, Tomohiko Kitajima, Mukund Srinivasan, Sanjay Natarajan
  • Patent number: 11158650
    Abstract: Embodiments of the present disclosure provide an apparatus and methods for forming stair-like structures with accurate profiles and dimension control for manufacturing three dimensional (3D) stacked memory cell semiconductor devices. In one embodiment, a memory cell device includes a film stack comprising alternating pairs of dielectric layers and conductive structures horizontally formed on a substrate, and an opening formed in the film stack, wherein the opening is filled with a metal dielectric layer, a multi-layer structure and a center filling layer, wherein the metal dielectric layer in the opening is interfaced with the conductive structure.
    Type: Grant
    Filed: October 18, 2019
    Date of Patent: October 26, 2021
    Assignee: Applied Materials, Inc.
    Inventors: ChangSeok Kang, Tomohiko Kitajima
  • Publication number: 20210257375
    Abstract: Methods and apparatus for forming a plurality of nonvolatile memory cells are provided herein. In some embodiments, the method, for example, includes forming a plurality of nonvolatile memory cells, comprising forming, on a substrate, a stack of alternating layers of metal including a first layer of metal and a second layer of metal different from the first layer of metal; removing the first layer of metal to form spaces between the alternating layers of the second layer of metal; and one of depositing a first layer of material to partially fill the spaces to leave air gaps therein or depositing a second layer of material to fill the spaces.
    Type: Application
    Filed: April 12, 2021
    Publication date: August 19, 2021
    Inventors: Takehito Koshizawa, Mukund Srinivasan, Tomohiko Kitajima, Chang Seok Kang, Sung-Kwan Kang, Gill Y. Lee, Susmit Singha Roy
  • Publication number: 20210249415
    Abstract: Memory devices incorporating bridged word lines are described. The memory devices include a plurality of active regions spaced along a first direction, a second direction and a third direction. A plurality of conductive layers is arranged so that at least one conductive layer is adjacent to at least one side of each of the active regions along the third direction. A conductive bridge extends along the second direction to connect each of the conductive layers to one or more adjacent conductive layer. Some embodiments include an integrated etch stop layer. Methods of forming stacked memory devices are also described.
    Type: Application
    Filed: January 27, 2021
    Publication date: August 12, 2021
    Applicant: Applied Materials, Inc.
    Inventors: CHANG SEOK KANG, Tomohiko Kitajima, Nitin K. Ingle, Sung-Kwan Kang
  • Publication number: 20210233779
    Abstract: Memory devices and methods of manufacturing memory devices are provided. The device and methods described suppress oxidation of metal layers exposed to ambient oxygen. After an opening is formed, a nitridation process occurs to nitridate the surface of the exposed metal layer inside the opening. The nitridated region formed on the surface of metal layer inside the opening works as a barrier layer for oxygen diffusion. In addition, the nitridated region works as an electrode for charge trap memory cells.
    Type: Application
    Filed: January 13, 2021
    Publication date: July 29, 2021
    Applicant: Applied Materials, Inc.
    Inventors: Chang Seok Kang, Tomohiko Kitajima, Sung-Kwan Kang
  • Publication number: 20210233918
    Abstract: Methods and apparatus for forming a plurality of nonvolatile memory cells are provided herein. In some embodiments, the method, for example, includes forming a plurality of nonvolatile memory cells, comprising forming, on a substrate, a stack of alternating layers of metal including a first layer of metal and a second layer of metal different from the first layer of metal; removing the first layer of metal to form spaces between the alternating layers of the second layer of metal; and one of depositing a first layer of material to partially fill the spaces to leave air gaps therein or depositing a second layer of material to fill the spaces.
    Type: Application
    Filed: April 12, 2021
    Publication date: July 29, 2021
    Inventors: Takehito Koshizawa, Mukund Srinivasan, Tomohiko Kitajima, Chang Seok Kang, Sung-Kwan Kang, Gill Y. Lee, Susmit Singha Roy