Patents by Inventor Hideko Okada

Hideko Okada 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: 5714400
    Abstract: On an insulating substrate are formed first aluminum interconnections. In openings formed in a silicon dioxide film are formed unit cells each consisting of a tungsten electrode and an aluminum alloy electrode containing silicon. Over the silicon dioxide film are formed a large number of linear second aluminum interconnections which are orthogonal to the first aluminum interconnections. At the individual intersections of the first and second aluminum interconnections are disposed the unit cells so as to compose a memory cell array. When a large current is allowed to flow through the unit cell, silicon in the aluminum alloy electrode moves in a direction opposite to the current flow and is precipitated in the aluminum electrode in the vicinity of the interface with the tungsten electrode, resulting in an increase in resistance value. When a large current is allowed to flow through the unit cell in the opposite direction, silicon is diffused, resulting in a reduction in resistance value.
    Type: Grant
    Filed: June 21, 1996
    Date of Patent: February 3, 1998
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Shuji Hirao, Hideko Okada, Kousaku Yano
  • Patent number: 5621247
    Abstract: On an insulating substrate are formed first aluminum interconnections. In openings formed in a silicon dioxide film are formed unit cells each consisting of a tungsten electrode and an aluminum alloy electrode containing silicon. Over the silicon dioxide film are formed a large number of linear second aluminum interconnections which are orthogonal to the first aluminum interconnections. At the individual intersections of the first and second aluminum interconnections are disposed the unit cells so as to compose a memory cell array. When a large current is allowed to flow through the unit cell, silicon in the aluminum alloy electrode moves in a direction opposite to the current flow and is precipitated in the aluminum electrode in the vicinity of the interface with the tungsten electrode, resulting in an increase in resistance value. When a large current is allowed to flow through the unit cell in the opposite direction, silicon is diffused, resulting in a reduction in resistance value.
    Type: Grant
    Filed: February 16, 1996
    Date of Patent: April 15, 1997
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Shuji Hirao, Hideko Okada, Kousaku Yano