Patents by Inventor Bruce A. Tuttle

Bruce A. Tuttle 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: 6225654
    Abstract: An improved ferroelectric FET structure in which the ferroelectric layer is doped to reduce retention loss. A ferroelectric FET according to the present invention includes a semiconductor layer having first and second contacts thereon, the first and second contacts being separated from one another. The ferroelectric FET also includes a bottom electrode and a ferroelectric layer which is sandwiched between the semiconductor layer and the bottom electrode. The ferroelectric layer is constructed from a perovskite structure of the chemical composition ABO3 wherein the B site comprises first and second elements and a dopant element that has an oxidation state greater than +4 in sufficient concentration to impede shifts in the resistance measured between the first and second contacts with time. The ferroelectric FET structure preferably comprises Pb in the A-site. The first and second elements are preferably Zr and Ti, respectively.
    Type: Grant
    Filed: May 1, 1996
    Date of Patent: May 1, 2001
    Assignee: Radiant Technologies, Inc
    Inventors: Joseph T. Evans, Jr., William L. Warren, Bruce A. Tuttle
  • Patent number: 5949071
    Abstract: A monolithic infrared detector structure which allows integration of pyroelectric thin films atop low thermal conductivity aerogel thin films. The structure comprises, from bottom to top, a substrate, an aerogel insulating layer, a lower electrode, a pyroelectric layer, and an upper electrode layer capped by a blacking layer. The aerogel can offer thermal conductivity less than that of air, while providing a much stronger monolithic alternative to cantilevered or suspended air-gap structures for pyroelectric thin film pixel arrays. Pb(Zr.sub.0.4 Ti.sub.0.6)O.sub.3 thin films deposited on these structures displayed viable pyroelectric properties, while processed at 550.degree. C.
    Type: Grant
    Filed: August 14, 1997
    Date of Patent: September 7, 1999
    Assignee: Sandia Corporation
    Inventors: Judith A. Ruffner, Jeff A. Bullington, Paul G. Clem, William L. Warren, C. Jeffrey Brinker, Bruce A. Tuttle, Robert W. Schwartz
  • Patent number: 5908802
    Abstract: A process for producing powders of perovskite-type compounds which comprises mixing a metal alkoxide solution with a lead acetate solution to form a homogeneous, clear metal solution, adding an oxalic acid/n-propanol solution to this metal solution to form an easily filterable, free-flowing precursor powder and then calcining this powder. This process provides fine perovskite-phase powders with ferroelectric properties which are particularly useful in a variety of electronic applications.
    Type: Grant
    Filed: October 30, 1997
    Date of Patent: June 1, 1999
    Assignee: Sandia Corporation
    Inventors: James A. Voigt, Diana L. Sipola, Bruce A. Tuttle, Mark T. Anderson
  • Patent number: 5677825
    Abstract: An improved ferroelectric capacitor exhibiting reduced imprint effects in comparison to prior art capacitors. A capacitor according to the present invention includes top and bottom electrodes and a ferroelectric layer sandwiched between the top and bottom electrodes, the ferroelectric layer comprising a perovskite structure of the chemical composition ABO.sub.3 wherein the B-site comprises first and second elements and a dopant element that has an oxidation state greater than +4. The concentration of the dopant is sufficient to reduce shifts in the coercive voltage of the capacitor with time. In the preferred embodiment of the present invention, the ferroelectric element comprises Pb in the A-site, and the first and second elements are Zr and Ti, respectively. The preferred dopant is chosen from the group consisting of Niobium, Tantalum, and Tungsten. In the preferred embodiment of the present invention, the dopant occupies between 1 and 8% of the B-sites.
    Type: Grant
    Filed: December 28, 1995
    Date of Patent: October 14, 1997
    Inventors: Joseph T. Evans, Jr., William L. Warren, Bruce A. Tuttle, Duane B. Dimos, Gordon E. Pike
  • Patent number: 5578846
    Abstract: An improved ferroelectric FET structure in which the ferroelectric layer is doped to reduce retention loss. A ferroelectric FET according to the present invention includes a semiconductor layer having first and second contacts thereon, the first and second contacts being separated from one another. The ferroelectric FET also includes a bottom electrode and a ferroelectric layer which is sandwiched between the semiconductor layer and the bottom electrode. The ferroelectric layer is constructed from a perovskite structure of the chemical composition ABO.sub.3 wherein the B site comprises first and second elements and a dopant element that has an oxidation state greater than +4 in sufficient concentration to impede shifts in the resistance measured between the first and second contacts with time. The ferroelectric FET structure preferably comprises Pb in the A-site. The first and second elements are preferably Zr and Ti, respectively.
    Type: Grant
    Filed: March 17, 1995
    Date of Patent: November 26, 1996
    Inventors: Joseph T. Evans, Jr., William L. Warren, Bruce A. Tuttle
  • Patent number: 4681717
    Abstract: Chemical preparation techniques involving co-precipitation of metals are used to provide micro-structural characteristics necessary in order to produce ZnO varistors and their precursors for high field applications. The varistors produced have homogeneous and/or uniform dopant distributions and a submicron average grain size with a narrow size distribution. Precursor powders are prepared via chemical precipitation techniques and varistors made by sintering uniaxially and/or isostatically pressed pellets. Using these methods, varistors were made which were suitable for high-power applications, having values of breakdown field, E.sub.B, in the 10-100 kV/cm range, .alpha.>30 and densities in the range of 65-99% of theoretical, depending on both composition and sintering temperature.
    Type: Grant
    Filed: February 19, 1986
    Date of Patent: July 21, 1987
    Assignee: The United States of America as represented by the United States Department of Energy
    Inventors: Robert A. Brooks, Robert G. Dosch, Bruce A. Tuttle