Patents by Inventor Tatsuyoshi MIHARA

Tatsuyoshi MIHARA 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: 11705361
    Abstract: Gate patterns are formed on a semiconductor layer and a conductive film is formed on the semiconductor layer so as to cover the gate patterns. By performing a polishing process to the conductive film and patterning the polished conductive film, pad layers are formed between the gate patterns via sidewall spacers.
    Type: Grant
    Filed: July 7, 2021
    Date of Patent: July 18, 2023
    Assignee: RENESAS ELECTRONICS CORPORATION
    Inventors: Hitoshi Maeda, Tatsuyoshi Mihara, Hiroki Shinkawata
  • Publication number: 20230083989
    Abstract: Reliability of a semiconductor device including a ferroelectric memory is improved. A gate electrode of a ferroelectric memory is formed on a semiconductor substrate so as to arrange a ferroelectric film therebetween, and a semiconductor layer serving as an epitaxial semiconductor layer is formed on the semiconductor substrate on both sides of the gate electrode. The semiconductor layer is formed on a dent portion of the semiconductor substrate. At least a part of each of a source region and a drain region of the ferroelectric memory is formed in the semiconductor layer.
    Type: Application
    Filed: July 6, 2022
    Publication date: March 16, 2023
    Inventor: Tatsuyoshi MIHARA
  • Publication number: 20230037374
    Abstract: A semiconductor device includes a plurality of word lines extending in a first direction in a plan view, a plurality of bit lines extending in a second direction orthogonal to the first direction in a plan view, and a plurality of memory cells arranged in matrix in the first direction and the second direction. The memory cell includes a gate insulating film, a lower layer electrode, a ferroelectric film, an upper layer electrode, and a pair of semiconductor regions, and a first width of the lower layer electrode in the first direction is larger than a second width of the upper layer electrode in the first direction in a plan view.
    Type: Application
    Filed: June 23, 2022
    Publication date: February 9, 2023
    Inventor: Tatsuyoshi MIHARA
  • Patent number: 11302791
    Abstract: In order to improve the reliability of a semiconductor device, in a memory cell of a split-gate type MONOS memory formed on a fin, a drain region is formed in an epitaxial layer on the fin, and a source region is formed in the fin, and a silicide layer is formed on an upper surface of the fin in which the source region is formed.
    Type: Grant
    Filed: April 21, 2020
    Date of Patent: April 12, 2022
    Assignee: RENESAS ELECTRONICS CORPORATION
    Inventor: Tatsuyoshi Mihara
  • Publication number: 20220068706
    Abstract: Gate patterns are formed on a semiconductor layer and a conductive film is formed on the semiconductor layer so as to cover the gate patterns. By performing a polishing process to the conductive film and patterning the polished conductive film, pad layers are formed between the gate patterns via sidewall spacers.
    Type: Application
    Filed: July 7, 2021
    Publication date: March 3, 2022
    Inventors: Hitoshi MAEDA, Tatsuyoshi MIHARA, Hiroki SHINKAWATA
  • Patent number: 11264244
    Abstract: After a MISFET is formed on a substrate including a semiconductor substrate, an insulating layer and a semiconductor layer, an interlayer insulating film and a first insulating film are formed on the substrate. Also, after an opening is formed in each of the first insulating film and the interlayer insulating film, a second insulating film is formed at each of a bottom portion of the opening and a side surface of the opening and also formed on an upper surface of the first insulating film. Further, each of the second insulating film formed at the bottom portion of the opening and the second insulating film formed on the upper surface of the first insulating film is removed by etching. After that, an inside of the opening is etched under a condition that each of the first insulating film and the second insulating film is less etched than the insulating layer.
    Type: Grant
    Filed: February 18, 2020
    Date of Patent: March 1, 2022
    Assignee: RENESAS ELECTRONICS CORPORATION
    Inventor: Tatsuyoshi Mihara
  • Patent number: 11183510
    Abstract: After a dummy control gate electrode and a memory gate electrode are formed and an interlayer insulating film is formed so as to cover the gate electrodes, the interlayer insulating film is polished to expose the dummy control gate electrode and the memory gate electrode. Thereafter, the dummy control gate electrode is removed by etching, and then a control gate electrode is formed in a trench which is a region from which the dummy control gate electrode has been removed. The dummy control gate electrode is made of a non-doped or n type silicon film, and the memory gate electrode is made of a p type silicon film. In the process of removing the dummy control gate electrode, the dummy control gate electrode is removed by performing etching under the condition that the memory gate electrode is less likely to be etched compared with the dummy control gate electrode, in the state where the dummy control gate electrode and the memory gate electrode are exposed.
    Type: Grant
    Filed: December 4, 2017
    Date of Patent: November 23, 2021
    Assignee: RENESAS ELECTRONICS CORPORATION
    Inventor: Tatsuyoshi Mihara
  • Publication number: 20210257217
    Abstract: After a MISFET is formed on a substrate including a semiconductor substrate, an insulating layer and a semiconductor layer, an interlayer insulating film and a first insulating film are formed on the substrate. Also, after an opening is formed in each of the first insulating film and the interlayer insulating film, a second insulating film is formed at each of a bottom portion of the opening and a side surface of the opening and also formed on an upper surface of the first insulating film. Further, each of the second insulating film formed at the bottom portion of the opening and the second insulating film formed on the upper surface of the first insulating film is removed by etching. After that, an inside of the opening is etched under a condition that each of the first insulating film and the second insulating film is less etched than the insulating layer.
    Type: Application
    Filed: February 18, 2020
    Publication date: August 19, 2021
    Inventor: Tatsuyoshi MIHARA
  • Patent number: 11037830
    Abstract: After the step of polishing, a part of each of each gate electrode is removed such that the upper surface of each gate electrode is located closer than the damaged region formed in the gate insulating film located between the gate electrodes to the main surface of the semiconductor substrate in cross-section view. Thus, it is possible to suppress the occurrence of a short-circuit defect during the operation of the semiconductor device.
    Type: Grant
    Filed: October 14, 2019
    Date of Patent: June 15, 2021
    Assignee: RENESAS ELECTRONICS CORPORATION
    Inventors: Naoki Takizawa, Tatsuyoshi Mihara
  • Publication number: 20210111256
    Abstract: After the step of polishing, a part of each of each gate electrode is removed such that the upper surface of each gate electrode is located closer than the damaged region formed in the gate insulating film located between the gate electrodes to the main surface of the semiconductor substrate in cross-section view. Thus, it is possible to suppress the occurrence of a short-circuit defect during the operation of the semiconductor device.
    Type: Application
    Filed: October 14, 2019
    Publication date: April 15, 2021
    Inventors: Naoki TAKIZAWA, Tatsuyoshi MIHARA
  • Publication number: 20200403073
    Abstract: In order to improve the reliability of a semiconductor device, in a memory cell of a split-gate type MONOS memory formed on a fin, a drain region is formed in an epitaxial layer on the fin, and a source region is formed in the fin, and a silicide layer is formed on an upper surface of the fin in which the source region is formed.
    Type: Application
    Filed: April 21, 2020
    Publication date: December 24, 2020
    Inventor: Tatsuyoshi Mihara
  • Patent number: 10629704
    Abstract: A semiconductor device in which the retention characteristics of a rewritable memory cell packaged together with a field effect transistor including a metal gate electrode are improved and a method for manufacturing the semiconductor device. The semiconductor device includes a field effect transistor with a metal gate electrode and a rewritable memory cell. The manufacturing method includes the step of replacing a dummy gate electrode with the metal gate electrode. Before the step of replacing the dummy gate electrode with the metal gate electrode, the method includes the steps of making the height of the memory cell lower than the height of the dummy gate electrode and forming a protective film for covering the memory cell.
    Type: Grant
    Filed: August 29, 2018
    Date of Patent: April 21, 2020
    Assignee: RENESAS ELECTRONICS CORPORATION
    Inventor: Tatsuyoshi Mihara
  • Patent number: 10573642
    Abstract: The improvement of the reliability of a semiconductor device having a split gate type MONOS memory is implemented. An ONO film and a second polysilicon film are sequentially formed so as to fill between a first polysilicon film and a dummy gate electrode. Then, the dummy gate electrode is removed. Then, the top surfaces of the first and second polysilicon films are polished, thereby to form a memory gate electrode formed of the second polysilicon film at the sidewall of a control gate electrode formed of the first polysilicon film via the ONO film. As a result, the memory gate electrode high in perpendicularity of the sidewall, and uniform in film thickness is formed.
    Type: Grant
    Filed: September 10, 2018
    Date of Patent: February 25, 2020
    Assignee: Renesas Electronics Corporation
    Inventor: Tatsuyoshi Mihara
  • Patent number: 10559500
    Abstract: An insulating film and another insulating film are formed over a semiconductor substrate in that order to cover first, second, and third gate electrodes. The another insulating film is etched back to form sidewall spacers over side surfaces of the insulating film. Then, the sidewall spacers over the side surfaces of the insulating films corresponding to the sidewalls of the first and second gate electrodes are removed to leave the sidewall spacers over the side surfaces of the insulating film corresponding to the sidewalls of the third gate electrode. Then, the sidewall spacers and the insulating films are etched back, so that the sidewall spacers are formed of the insulating film over the sidewalls of the first, second, and third gate electrodes.
    Type: Grant
    Filed: April 11, 2018
    Date of Patent: February 11, 2020
    Assignee: RENESAS ELECTRONICS CORPORATION
    Inventors: Koji Maekawa, Tatsuyoshi Mihara
  • Publication number: 20190312043
    Abstract: Provided is an inexpensive high-performance split gate MONOS memory. In a manufacturing process of a split gate MONOS memory, a protective layer is formed in an upper part of a control gate electrode before metal substitution of a memory gate electrode.
    Type: Application
    Filed: March 22, 2019
    Publication date: October 10, 2019
    Inventor: Tatsuyoshi MIHARA
  • Patent number: 10325921
    Abstract: To improve reliability of a semiconductor device, a control transistor and a memory transistor formed in a memory cell region are configured to have a double-gate structure, and a transistor formed in a peripheral circuit region is configured to have a triple-gate structure. For example, in the memory transistor, a gate insulating film formed by an ONO film is provided between a memory gate electrode and sidewalls of a fin, and an insulating film (a stacked film of a multilayer film of an insulating film/an oxide film and the ONO film) thicker than the ONO film is provided between the memory gate electrode and a top surface of the fin. This configuration can reduce concentration of an electric field onto a tip of the fin, so that deterioration of reliability of the ONO film can be prevented.
    Type: Grant
    Filed: November 13, 2018
    Date of Patent: June 18, 2019
    Assignee: RENESAS ELECTRONICS CORPORATION
    Inventor: Tatsuyoshi Mihara
  • Publication number: 20190148518
    Abstract: A semiconductor device in which the retention characteristics of a rewritable memory cell packaged together with a field effect transistor including a metal gate electrode are improved and a method for manufacturing the semiconductor device. The semiconductor device includes a field effect transistor with a metal gate electrode and a rewritable memory cell. The manufacturing method includes the step of replacing a dummy gate electrode with the metal gate electrode. Before the step of replacing the dummy gate electrode with the metal gate electrode, the method includes the steps of making the height of the memory cell lower than the height of the dummy gate electrode and forming a protective film for covering the memory cell.
    Type: Application
    Filed: August 29, 2018
    Publication date: May 16, 2019
    Inventor: Tatsuyoshi MIHARA
  • Patent number: 10263005
    Abstract: A control gate electrode and a memory gate electrode of a memory cell of a non-volatile memory are formed in a memory cell region of a semiconductor substrate, and a dummy gate electrode is formed in a peripheral circuit region. Then, n+-type semiconductor regions for a source or a drain of the memory cell are formed in the memory cell region and n+-type semiconductor regions for a source or a drain of MISFET are formed in the peripheral circuit region. Then, a metal silicide layer is formed over the n+-type semiconductor regions but the metal silicide layer is not formed over the control gate electrode, the memory gate electrode, and the gate electrode. Subsequently, the gate electrode is removed and replaced with the gate electrode for MISFET. Then, after removing the gate electrode and replacing it with a gate electrode for MISFET, a metal silicide layer is formed over the memory gate electrode and the control gate electrode.
    Type: Grant
    Filed: August 30, 2017
    Date of Patent: April 16, 2019
    Assignee: Renesas Electronics Corporation
    Inventors: Keisuke Tsukamoto, Tatsuyoshi Mihara
  • Publication number: 20190103413
    Abstract: To improve reliability of a semiconductor device, a control transistor and a memory transistor formed in a memory cell region are configured to have a double-gate structure, and a transistor formed in a peripheral circuit region is configured to have a triple-gate structure. For example, in the memory transistor, a gate insulating film formed by an ONO film is provided between a memory gate electrode and sidewalls of a fin, and an insulating film (a stacked film of a multilayer film of an insulating film/an oxide film and the ONO film) thicker than the ONO film is provided between the memory gate electrode and a top surface of the fin. This configuration can reduce concentration of an electric field onto a tip of the fin, so that deterioration of reliability of the ONO film can be prevented.
    Type: Application
    Filed: November 13, 2018
    Publication date: April 4, 2019
    Applicant: Renesas Electronics Corporation
    Inventor: Tatsuyoshi MIHARA
  • Patent number: 10229998
    Abstract: Variations in height of a top of an element isolation region, which is embedded in a trench surrounding the periphery of a fin having a channel region of a split-gate MONOS memory, are suppressed to improve reliability of a semiconductor device. An element isolation region embedded in a trench between a plurality of fins, which are part of a semiconductor substrate in a memory cell region and protrude above the semiconductor substrate, is comprised of an insulating film covering the bottom of the trench and a silicon nitride film covering the top of the insulating film.
    Type: Grant
    Filed: March 7, 2018
    Date of Patent: March 12, 2019
    Assignee: RENESAS ELECTRONICS CORPORATION
    Inventor: Tatsuyoshi Mihara