Patents by Inventor Akifumi Yao

Akifumi Yao 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).

  • Publication number: 20210115556
    Abstract: A treatment method for a metal oxyfluoride according to the present invention includes bringing a metal oxyfluoride of the general formula: MO(6-x)/2Fx (where 0<x<6; and M=W or Mo) into contact with a fluorine-containing gas at a reaction temperature higher than or equal to 0° C. and lower than 400° C., thereby converting the metal oxyfluoride to a metal hexafluoride of the general formula: MF6 (where M=W or Mo). This treatment method enables conversion of the metal oxyfluoride to the high vapor pressure compound without the use of a plasma generator and can be applied to cleaning of a metal fluoride production apparatus or cleaning of a film forming apparatus.
    Type: Application
    Filed: May 31, 2018
    Publication date: April 22, 2021
    Inventors: Masakiyo NAGATOMO, Akifumi YAO
  • Patent number: 10957554
    Abstract: Disclosed is a dry etching method for etching a metal film on a substrate with the use of an etching gas, wherein the etching gas contains a ?-diketone and first and second additive gases; wherein the metal film contains a metal element capable of forming a complex with the ?-diketone; wherein the first additive gas is at least one kind of gas selected from the group consisting of NO, NO2, O2 and O3; wherein the second additive gas is at least one kind of gas selected from the group consisting of H2O and H2O2; wherein the amount of the ?-diketone contained is 10 vol % to 90 vol % relative to the etching gas; and wherein the amount of the second additive gas contained is 0.1 vol % to 15 vol % relative to the etching gas. The etching rate of the metal film is increased by this etching method.
    Type: Grant
    Filed: December 20, 2017
    Date of Patent: March 23, 2021
    Assignee: Central Glass Company, Limited
    Inventors: Kunihiro Yamauchi, Takashi Masuda, Akifumi Yao
  • Publication number: 20210054275
    Abstract: A substrate processing gas of the present invention contains IF5; and IF7, in which a content of the IF5 is equal to or more than 1 ppm and equal to or less than 2% on a volume basis with respect to a total amount of the IF5 and the IF7.
    Type: Application
    Filed: March 5, 2019
    Publication date: February 25, 2021
    Applicant: CENTRAL GLASS COMPANY, LIMITED
    Inventors: Akifumi YAO, Yuuta TAKEDA, Jun ETO
  • Patent number: 10926211
    Abstract: Disclosed is a purification method for removing a metal component from a fluorine compound gas containing hydrogen fluoride and a metal component. This method includes a removing step for removing the hydrogen fluoride and the metal component therefrom by bringing the fluorine compound gas into contact with a solid metal fluoride to adsorb the hydrogen fluoride and the metal component on the metal fluoride. It is preferable for the fluorine compound gas to contain at least one kind selected from the group consisting of CIF, CIF3, IF5, IF7, BrF3, BrF5, NF3, WF6, SiF4, CF4, SF6 and BF3. It is also preferable for the metal fluoride to be an alkali metal fluoride or an alkali earth metal fluoride. Surprisingly, the presence of hydrogen fluoride in a fluorine compound gas makes it possible to remove a metal component therefrom as an impurity as a result of adsorption thereof by a metal fluoride.
    Type: Grant
    Filed: January 27, 2017
    Date of Patent: February 23, 2021
    Assignee: Central Glass Company, Limited
    Inventors: Akifumi Yao, Kohei Ooya, Yuta Takeda, Jun Eto
  • Patent number: 10872780
    Abstract: Disclosed is the invention of a dry etching agent composition including: 1,3,3,3-tetrafluoropropene; and a hydrochlorofluorocarbon represented by CHxClyFz (wherein x, y and z are integers of 1 or greater and x+y+z=4), wherein a concentration of the hydrochlorofluorocarbon relative to 1,3,3,3-tetrafluoropropene is 3 volume ppm or greater to less than 10000 volume ppm, and a use of this dry etching agent composition. An object of the present invention is to suppress corrosion of storage container, pipes and an etching chamber by suppressing generation of acidic substances by improving storage stability of HFO-1234ze without losing excellent etching characteristics of HFO-1234ze.
    Type: Grant
    Filed: October 23, 2017
    Date of Patent: December 22, 2020
    Assignee: Central Glass Company, Limited
    Inventors: Hiroyuki Oomori, Akifumi Yao, Isamu Mori
  • Publication number: 20200365411
    Abstract: A dry etching method according to the present invention includes etching silicon nitride by bringing a mixed gas containing hydrogen fluoride and a fluorine-containing carboxylic acid into contact with the silicon nitride in a plasma-less process at a temperature lower than 100° C. Preferably, the amount of the fluorine-containing carboxylic acid contained is 0.01 vol % or more based on the total amount of the hydrogen fluoride and the fluorine-containing carboxylic acid. Examples of the fluorine-containing carboxylic acid are monofluoroacetic acid, difluoroacetic acid, trifluoroacetic acid, difluoropropionic acid, pentafluoropropionic acid, pentafluorobutyric acid and the like. This dry etching method enables etching of the silicon nitride at a high etching rate and shows a high selectivity ratio of the silicon nitride to silicon oxide and polycrystalline silicon while preventing damage to the silicon oxide.
    Type: Application
    Filed: October 24, 2018
    Publication date: November 19, 2020
    Inventors: Shoi SUZUKI, Akifumi YAO
  • Patent number: 10741406
    Abstract: Disclosed is a dry etching method for etching a laminated film of silicon oxide layers and silicon nitride layers on a substrate. The dry etching method includes providing a mask on the laminated film, generating a plasma from a dry etching agent and etching the laminated film by the plasma through the mask under a bias voltage of 500 V or higher to form a through hole in the laminated film vertically to the layers, wherein the dry etching agent contains at least C3H2F4, an unsaturated perfluorocarbon represented by CxFy and an oxidizing gas, and wherein a volume of the unsaturated perfluorocarbon contained in the dry etching agent is 0.1 to 10 times a volume of the C3H2F4 contained in the dry etching agent.
    Type: Grant
    Filed: July 1, 2016
    Date of Patent: August 11, 2020
    Assignee: Central Glass Company, Limited
    Inventors: Hiroyuki Oomori, Akifumi Yao
  • Publication number: 20200247685
    Abstract: According to the present invention, there is provided a method of producing tungsten hexafluoride by reacting tungsten with a fluorine-containing gas at a temperature of 800° C. or higher. The method according to the present invention is advantageous in that the amount of production of the tungsten hexafluoride per unit capacity of the reaction vessel is increased as compared to conventional techniques of producing tungsten hexafluoride from a fluorine-containing gas and metal tungsten while controlling the reaction temperature to 400° C. or lower. It is preferable that the reaction vessel is equipped with a coolant jacket for maintaining an inner wall temperature of the reaction vessel at 400° C. or lower.
    Type: Application
    Filed: October 4, 2018
    Publication date: August 6, 2020
    Inventors: Masakiyo NAGATOMO, Akifumi YAO, Shuhei UESHIMA, Akiou KIKUCHI
  • Publication number: 20200227721
    Abstract: To provide a carbon black for batteries capable of readily obtaining a positive electrode for batteries having excellent adhesiveness, and excellent output characteristics and the cycle characteristics. A carbon black for batteries, the carbon black having a BET specific surface area measured according to JIS K6217-2 C method of 100 m2/g or larger, and a surface fluorine concentration X (unit: atom %) and a surface oxygen concentration Y (unit: atom %) measured by X-ray Photoelectron Spectroscopy (XPS) satisfying the following conditions (A) and (B), 0.3?X?4.0 and??(A) 0.1?Y?3.0.
    Type: Application
    Filed: March 18, 2020
    Publication date: July 16, 2020
    Inventors: Shinichiro OSUMI, Tatsuya NAGAI, Takako ARAI, Tetsuya ITO, Hiroyuki OOMORI, Shoi SUZUKI, Akifumi YAO
  • Publication number: 20200173009
    Abstract: The method for producing a filled container of the present invention includes: providing a metal storage container, at least an inner surface of which is formed of a manganese steel and in which the inner surface has a surface roughness Rmax of 10 ?m or less; performing fluorination by bringing the inner surface of the storage container into contact with a gas containing at least one first fluorine-containing gas selected from the group consisting of ClF3, IF7, BrF5, F2, and WF6 at 50° C. or lower; purging the inside of the storage container with an inert gas; and filling the inside of the storage container with at least one second fluorine-containing gas selected from the group consisting of ClF3, IF7, BrF5, F2, and WF6.
    Type: Application
    Filed: July 24, 2018
    Publication date: June 4, 2020
    Inventors: Akifumi YAO, Masakiyo NAGATOMO, Shinya IKEDA
  • Publication number: 20200066541
    Abstract: Disclosed is a dry etching method for etching a metal film on a substrate with the use of an etching gas, wherein the etching gas contains a ?-diketone and first and second additive gases; wherein the metal film contains a metal element capable of forming a complex with the ?-diketone; wherein the first additive gas is at least one kind of gas selected from the group consisting of NO, NO2, O2 and O3; wherein the second additive gas is at least one kind of gas selected from the group consisting of H2O and H2O2; wherein the amount of the ?-diketone contained is 10 vol % to 90 vol % relative to the etching gas; and wherein the amount of the second additive gas contained is 0.1 vol % to 15 vol % relative to the etching gas. The etching rate of the metal film is increased by this etching method.
    Type: Application
    Filed: December 20, 2017
    Publication date: February 27, 2020
    Inventors: Kunihiro YAMAUCHI, Takashi MASUDA, Akifumi YAO
  • Publication number: 20190355590
    Abstract: Disclosed is a dry etching method which includes: a first step of bringing a processing gas containing a fluorine-containing interhalogen compound into contact with a material containing a specific metal element at a reaction temperature of 0° C. to 100° C., thereby forming a reaction product of the specific metal element and the fluorine-containing interhalogen compound as a solid product; and a second step of evaporating the solid product by heating the solid product in an inert gas atmosphere or vacuum atmosphere at a temperature higher than the reaction temperature of the first step, wherein the specific metal element is one or more kinds of elements selected from the group consisting of Ru, Ta, and Nb.
    Type: Application
    Filed: March 19, 2018
    Publication date: November 21, 2019
    Inventors: Shoi SUZUKI, Akifumi YAO
  • Publication number: 20190348307
    Abstract: Disclosed is a dry etching method for etching a metal film on a substrate with an etching gas containing a ?-diketone and an additive gas, wherein the metal film contains a metal element capable of forming a complex with the ?-diketone; and wherein the amount of water contained in the etching gas is 30 mass ppm or less relative to the amount of the ?-diketone. It is preferable that the ?-diketone used for the dry etching method is supplied from a ?-diketone filled container, wherein the ?-diketone filled container has a sealed container body filled with a ?-diketone whose water content is 15 mass ppm or less relative to the ?-diketone. This etching method enables etching of the metal film while suppressing etching rate variations from the initial stage to the later stage of use of the filled container.
    Type: Application
    Filed: December 20, 2017
    Publication date: November 14, 2019
    Inventors: Kunihiro YAMAUCHI, Takashi MASUDA, Akifumi YAO
  • Publication number: 20190345385
    Abstract: The present invention aims to provide a dry etching agent having less load on global environment and capable of anisotropic etching without the use of special equipment and obtaining a good processing shape and to provide a dry etching method using the dry etching agent. The dry etching agent according the present invention contains at least a hydrofluoroalkylene oxide represented by the following chemical formula: CF3—CxHyFzO (where x=2 or 3; y=1, 2, 3, 4 or 5; and z=2x?1?y) and having an oxygen-containing three-membered ring. The dry etching method according to the present invention includes selectively etching of at least one kind of silicon-based material selected from the group consisting of silicon dioxide, silicon nitride, polycrystalline silicon, amorphous silicon and silicon carbide with the use of a plasma gas generated by plasmatization of the dry etching agent.
    Type: Application
    Filed: February 20, 2018
    Publication date: November 14, 2019
    Inventors: Hiroyuki OOMORI, Akifumi YAO, Takashi KASHIWABA
  • Patent number: 10460946
    Abstract: A technique capable of removing a natural oxide film formed on a surface of a semiconductor layer which contains a compound of indium and an element other than indium as a main ingredient, without making a temperature of the semiconductor layer relatively high. The technique includes supplying a first etching gas which is ?-diketone to the semiconductor layer and heating the semiconductor layer to remove an oxide of the indium constituting the natural oxide film; and supplying a second etching gas to the semiconductor layer and heating the semiconductor layer to remove an oxide of the element constituting the natural oxide film. By using the first etching gas, it is possible to remove the indium oxide even if the temperature of the semiconductor layer is relatively low. This eliminates the need to increase the temperature to a relatively high level when removing the natural oxide film.
    Type: Grant
    Filed: June 7, 2016
    Date of Patent: October 29, 2019
    Assignees: TOKYO ELECTRON LIMITED, CENTRAL GLASS CO., LTD.
    Inventors: Jun Lin, Koji Takeya, Shinichi Kawaguchi, Mitsuhiro Tachibana, Akifumi Yao, Kunihiro Yamauchi
  • Patent number: 10457866
    Abstract: What is disclosed is a dry etching gas containing 1,3,3,3-tetrafluoropropene, wherein 1,3,3,3-tetrafluoropropene has purity of 99.5 mass % or more, and a total of concentration of each mixed metal component of Fe, Ni, Cr, Al, and Mo is 500 mass ppb or less. Furthermore, regarding to the dry etching gas, it is preferable that a content of nitrogen is 0.5 volume % or less, and that a content of water is 0.05 mass % or less. In a dry etching with a plasma gas obtained by making a dry etching gas into plasma, the dry etching gas of the present invention can improve etching selectivity of silicon-based material with respect to a mask.
    Type: Grant
    Filed: March 4, 2016
    Date of Patent: October 29, 2019
    Assignee: Central Glass Company, Limited
    Inventors: Yosuke Nakamura, Masaki Fujiwara, Hiroyuki Oomori, Akifumi Yao
  • Publication number: 20190287812
    Abstract: Disclosed is the invention of a dry etching agent composition including: 1,3,3,3-tetrafluoropropene; and a hydrochlorofluorocarbon represented by CHxClyFz (wherein x, y and z are integers of 1 or greater and x+y+z=4), wherein a concentration of the hydrochlorofluorocarbon relative to 1,3,3,3-tetrafluoropropene is 3 volume ppm or greater to less than 10000 volume ppm, and a use of this dry etching agent composition. An object of the present invention is to suppress corrosion of storage container, pipes and an etching chamber by suppressing generation of acidic substances by improving storage stability of HFO-1234ze without losing excellent etching characteristics of HFO-1234ze.
    Type: Application
    Filed: October 23, 2017
    Publication date: September 19, 2019
    Inventors: Hiroyuki OOMORI, Akifumi YAO, Isamu MORI
  • Publication number: 20190047858
    Abstract: Disclosed is a purification method for removing a metal component from a fluorine gas containing hydrogen fluoride and a metal component. This method includes a removing step for removing the hydrogen fluoride and the metal component therefrom by bringing the fluorine gas into contact with a solid metal fluoride to adsorb the hydrogen fluoride and the metal component on the metal fluoride. The content of the hydrogen fluoride in the fluorine gas before the removing step is 50 volume ppm to 1 volume %, relative to the total volume of the fluorine gas, the hydrogen fluoride and the metal component. The metal fluoride is preferably an alkali metal fluoride or an alkali earth metal fluoride. Surprisingly, the presence of hydrogen fluoride in a fluorine gas makes it possible to remove a metal component therefrom as an impurity as a result of adsorption thereof by a metal fluoride.
    Type: Application
    Filed: January 27, 2017
    Publication date: February 14, 2019
    Applicant: Central Glass Company, Limited
    Inventors: Akifumi YAO, Kohei OOYA, Yuta TAKEDA, Jun ETO
  • Publication number: 20190046917
    Abstract: Disclosed is a purification method for removing a metal component from a fluorine compound gas containing hydrogen fluoride and a metal component. This method includes a removing step for removing the hydrogen fluoride and the metal component therefrom by bringing the fluorine compound gas into contact with a solid metal fluoride to adsorb the hydrogen fluoride and the metal component on the metal fluoride. It is preferable for the fluorine compound gas to contain at least one kind selected from the group consisting of CIF, CIF3, IF5, IF7, BrF3, BrF5, NF3, WF6, SiF4, CF4, SF6 and BF3. It is also preferable for the metal fluoride to be an alkali metal fluoride or an alkali earth metal fluoride. Surprisingly, the presence of hydrogen fluoride in a fluorine compound gas makes it possible to remove a metal component therefrom as an impurity as a result of adsorption thereof by a metal fluoride.
    Type: Application
    Filed: January 27, 2017
    Publication date: February 14, 2019
    Applicant: Central Glass Company, Limited
    Inventors: Akifumi YAO, Kohei OOYA, Yuta TAKEDA, Jun ETO
  • Publication number: 20180323076
    Abstract: A processing method of a semiconductor substrate according the present invention includes: cleaning a surface of the semiconductor substrate with a water-based cleaning liquid; and drying the semiconductor substrate by replacing the water-based cleaning liquid attached to the surface of the semiconductor substrate with a supercritical fluid, characterized by using as the supercritical fluid a C2-C6 fluoroalcohol-containing solvent whose Fe, Ni, Cr, Al, Zn, Cu, Mg, Li, K, Na and Ca contents are each 500 mass ppb or less. In this processing method, it is possible to reduce the amount of fluorine atoms released in the supercritical fluid.
    Type: Application
    Filed: October 26, 2016
    Publication date: November 8, 2018
    Applicant: Central Glass Company ,Limited
    Inventors: Akifumi YAO, Soichi KUMON, Masaki FUJIWARA, Hidehisa NANAI