Patents by Inventor Tetsuya Kuwajima

Tetsuya Kuwajima 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: 6150720
    Abstract: In a wiring forming method according to the present invention, an insulating layer is formed on a semiconductor substrate, and contact holes are formed in the insulating layer. A titanium layer is deposited on the insulating layer so as to be along inner surfaces of the contact holes. A first titanium nitride layer is formed on the titanium layer including the titanium layer formed in the contact holes. The deposition of the first titanium nitride layer is carried out under atmosphere which substantially includes no oxygen. A titanium oxynitride layer is deposited on the first titanium nitride layer. A second titanium nitride layer is deposited on the titanium oxynitride layer. Buried plugs are formed on the second titanium nitride layer formed in the contact holes. A wiring connected to the buried plugs are formed on the insulating layer. A barrier metal layer and the buried plugs are thus formed in the contact holes. According to such the structure, a stable electric contact can be obtained.
    Type: Grant
    Filed: December 30, 1998
    Date of Patent: November 21, 2000
    Assignee: Yamaha Corporation
    Inventors: Takahisa Yamaha, Tetsuya Kuwajima
  • Patent number: 6146998
    Abstract: In a wiring forming method according to the present invention, an insulating layer is formed on a semiconductor substrate, and contact holes are formed in the insulating layer. A titanium layer is deposited on the insulating layer so as to be along inner surfaces of the contact holes. A first titanium nitride layer is formed on the titanium layer including the titanium layer formed in the contact holes. The deposition of the first titanium nitride layer is carried out under atmosphere which substantially includes no oxygen. A titanium oxynitride layer is deposited on the first titanium nitride layer. A second titanium nitride layer is deposited on the titanium oxynitride layer. Buried plugs are formed on the second titanium nitride layer formed in the contact holes. A wiring connected to the buried plugs are formed on the insulating layer. A barrier metal layer and the buried plugs are thus formed in the contact holes. According to such the structure, a stable electric contact can be obtained.
    Type: Grant
    Filed: August 24, 1998
    Date of Patent: November 14, 2000
    Assignee: Yamaha Corporation
    Inventors: Takahisa Yamaha, Tetsuya Kuwajima
  • Patent number: 5776827
    Abstract: An insulating layer 6 is formed covering a lower level wiring layer 5. Contact hole 11 registered with the lower level wiring 5 is then formed in the insulating layer 6. An adhesion layer 12 is sputtered on the lower level wiring layer 5 and a whole surface of the third level insulating layer 6. Then, a blanket tungsten layer 13 is deposited on the adhesion layer 12. The whole surface of the blanket tungsten layer 13 is etched back until a small hollow gap is formed at the upper end portion of the contact hole 11, to leave the blanket tungsten layer 13 only in the inside of the contact hole 11. Thereafter, an Al alloy layer is reflow-sputtered on the whole surface of the insulating layer 6 and the inside of the contact holes at a comparatively low temperature to form an upper level wiring layer 15. The surface unevenness produced in etch-back process can be planarized. A wiring having a good coverage, a good quality of layer, and a flat surface can be formed.
    Type: Grant
    Filed: May 2, 1996
    Date of Patent: July 7, 1998
    Assignee: Yamaha Corporation
    Inventors: Satoshi Hibino, Tetsuya Kuwajima
  • Patent number: 5679981
    Abstract: A first contact hole and a second contact hole are formed in an insulating film on the surface of a substrate, and thereafter a blanket tungsten (W) layer is deposited on the substrate surface, with or without a barrier metal layer being interposed therebetween. The first contact hole has a small size a so that the W layer can fully bury the first contact hole, whereas the second contact hole has a large size b over a size c where a<c<b so that a desired wiring layer coverage ratio is attained. The deposited W layer is etched back while leaving the W layer in the first contact hole and a tapered W layer in the second contact hole. A wiring layer such as Al alloy is deposited on the substrate surface. The unnecessary wiring layer and barrier metal layer are patterned to form a wiring pattern. Wiring layers having a good burying state and a good coverage state can be obtained. A yield of manufacturing wiring layers can be improved.
    Type: Grant
    Filed: April 17, 1996
    Date of Patent: October 21, 1997
    Assignee: Yamaha Corporation
    Inventor: Tetsuya Kuwajima
  • Patent number: 5534461
    Abstract: A first contact hole and a second contact hole are formed in an insulating film on the surface of a substrate, and thereafter a blanket tungsten (W) layer is deposited on the substrate surface, with or without a barrier metal layer being interposed therebetween. The first contact hole has a small size a so that the W layer can fully bury the first contact hole, whereas the second contact hole has a large size b over a size c where a<c<b so that a desired wiring layer coverage ratio is attained. The deposited W layer is etched back while leaving the W layer in the first contact hole and a tapered W layer in the second contact hole. A wiring layer such as Al alloy is deposited on the substrate surface. The unnecessary wiring layer and barrier metal layer are patterned to form a wiring pattern. Wiring layers having a good burying state and a good coverage state can be obtained. A yield of manufacturing wiring layers can be improved.
    Type: Grant
    Filed: March 2, 1995
    Date of Patent: July 9, 1996
    Assignee: Yamaha Corporation
    Inventor: Tetsuya Kuwajima
  • Patent number: 5529955
    Abstract: An insulating layer 6 is formed covering a lower level wiring layer 5. Contact hole 11 registered with the lower level wiring 5 is then formed in the insulating layer 6. An adhesion layer 12 is formed on the lower level wiring layer 5 and a whole surface of the third level insulating layer 6. Then, a tungsten layer 13 is formed on the adhesion layer 12. The whole surface of the tungsten layer 13 is etched back until a small hollow gap is formed at the upper end portion of the contact hole 11, to leave the tungsten layer 13 only in the inside of the contact hole 11. Thereafter, an Al alloy layer is reflow-sputtered on the whole surface of the insulating layer 6 and the inside of the contact holes at a comparatively low temperature to form an upper level wiring layer 15. The surface unevenness produced in etch-back process can be planarized. A wiring having a good coverage, a good quality of layer, and a flat surface can be formed.
    Type: Grant
    Filed: August 25, 1994
    Date of Patent: June 25, 1996
    Assignee: Yamaha Corporation
    Inventors: Satoshi Hibino, Tetsuya Kuwajima