Patents by Inventor Tom Davenport

Tom Davenport 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: 5969935
    Abstract: A lead zirconate titanate ferroelectric film used as the dielectric layer in a ferroelectric capacitor is doped with calcium and/or strontium, and the lead composition selected to improve data retention performance. The chemical formula for the ferroelectric film is: (Pb.sub.v Ca.sub.w Sr.sub.x La.sub.y)(Zr.sub.z Ti.sub.(1-z))O.sub.3 ; wherein v is ideally between 0.9 and 1.3; w is ideally between 0 and 0.1; x is ideally between 0 and 0.1; y is ideally between 0 and 0.1, and z is ideally between 0 and 0.9. In addition, the chemical composition of the ferroelectric film is further specified in that the measured opposite state charge at a specific time and temperature of the ferroelectric capacitor is greater than eight micro-Coulombs per square centimeter, and the rate of imprint degradation is less than fifteen percent per decade.
    Type: Grant
    Filed: March 15, 1996
    Date of Patent: October 19, 1999
    Assignee: Ramtron International Corporation
    Inventors: Lee Kammerdiner, Tom Davenport, Domokos Hadnagy
  • Patent number: 5800683
    Abstract: A lead zirconate titanate ferroelectric film used as the dielectric layer in a ferroelectric capacitor is doped with calcium and/or strontium, and the lead composition selected to improve data retention performance. The chemical formula for the ferroelectric film is: (Pb.sub.v Ca.sub.w Sr.sub.x La.sub.y)(Zr.sub.z Ti.sub.(1-z))O.sub.3 ; wherein v is ideally between 0.9 and 1.3; w is ideally between 0 and 0.1; x is ideally between 0 and 0.1; y is ideally between 0 and 0.1, and z is ideally between 0 and 0.9. In addition, the chemical composition of the ferroelectric film is further specified in that the measured opposite state charge at a specific time and temperature of the ferroelectric capacitor is greater than eight micro-Coulombs per square centimeter, and the rate of imprint degradation is less than fifteen percent per decade.
    Type: Grant
    Filed: May 22, 1997
    Date of Patent: September 1, 1998
    Assignee: Ramtron International Corporation
    Inventors: Lee Kammerdiner, Tom Davenport, Domokos Hadnagy