Patents by Inventor Charles H. Ahn

Charles H. Ahn 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: 9536975
    Abstract: Ferroelectric semiconductor devices are provided by including a ferroelectric layer in the device that is made of a material that is not ferroelectric in bulk. Such layers can be disposed at interfaces to promote ferroelectric switching in a semiconductor device. Switching of conduction in the semiconductor is effected by the polarization of a mechanically bi-stable material. This material is not ferroelectric in bulk but can be considered to be when the thickness is sufficiently reduced down to a few atomic layers. Devices including such ferroelectric layers are suitable for various applications, such as transistors and memory cells (both volatile and non-volatile).
    Type: Grant
    Filed: June 21, 2015
    Date of Patent: January 3, 2017
    Assignee: Yale University
    Inventors: Alexie M. Kolpak, Fred J. Walker, James W. Reiner, Charles H. Ahn, Sohrab Ismail-Beigi
  • Publication number: 20150311309
    Abstract: Ferroelectric semiconductor devices are provided by including a ferroelectric layer in the device that is made of a material that is not ferroelectric in bulk. Such layers can be disposed at interfaces to promote ferroelectric switching in a semiconductor device. Switching of conduction in the semiconductor is effected by the polarization of a mechanically bi-stable material. This material is not ferroelectric in bulk but can be considered to be when the thickness is sufficiently reduced down to a few atomic layers. Devices including such ferroelectric layers are suitable for various applications, such as transistors and memory cells (both volatile and non-volatile).
    Type: Application
    Filed: June 21, 2015
    Publication date: October 29, 2015
    Inventors: Alexie M. Kolpak, Fred J. Walker, James W. Reiner, Charles H. Ahn, Sohrab Ismail-Beigi
  • Publication number: 20130001809
    Abstract: Ferroelectric semiconductor devices are provided by including a ferroelectric layer in the device that is made of a material that is not ferroelectric in bulk. Such layers can be disposed at interfaces to promote ferroelectric switching in a semiconductor device. Switching of conduction in the semiconductor is effected by the polarization of a mechanically bi-stable material. This material is not ferroelectric in bulk but can be considered to be when the thickness is sufficiently reduced down to a few atomic layers. Devices including such ferroelectric layers are suitable for various applications, such as transistors and memory cells (both volatile and non-volatile).
    Type: Application
    Filed: September 29, 2010
    Publication date: January 3, 2013
    Inventors: Alexie M. Kolpak, Fred J. Walker, James W. Reiner, Charles H. Ahn, Sohrab Ismail-Beigi
  • Patent number: 6677629
    Abstract: The invention concerns a component of composite structure (10) consisting of a layer of ferroelectric material (11) and at least a thin film of semiconductor material or of a thin metal or supraconducting film (12) in close contact with the layer of ferroelectric material (11). It further comprises means for generating local modifications of the ferroelectric material polarization. This mechanism includes a device for applying a voltage between at least one punctiform electrode (13) arranged for selectively scanning the composite structure (10) surface facing that consisting of the semiconductor or thin metal or supraconducting film (12), and the semiconductor or thin metal or supraconducting film.
    Type: Grant
    Filed: September 30, 1999
    Date of Patent: January 13, 2004
    Assignee: Universite de Geneve
    Inventors: Oystein Fischer, Jean-Marc Triscone, Charles H. Ahn, Malcom R. Beasley, Christophe Renner, Thomas Tybell
  • Patent number: 5530541
    Abstract: An atomic absorption apparatus using a laser for producing a light beam having a characteristic frequency f, typically ranging from several MHz to several GHz, and a characteristic polarization for measuring the absorption of that light beam by atoms of interest. The apparatus has a modulator to generate a modulating signal to modulate the characteristic frequency f and produce a phase-modulated light beam. The apparatus includes a domain where the specific atoms are located. This domain is positioned in the path of the phase-modulated light beam such that the phase-modulated light beam encounters the specific atoms when passing through the domain and some of the specific atoms absorb a portion of the phase-modulated light beam. Typically, the domains containing the atoms of interest include process chambers for vacuum coating, ion milling, sputtering, mass spectroscopy vapor coating or deposition, and the like.
    Type: Grant
    Filed: February 28, 1995
    Date of Patent: June 25, 1996
    Assignee: Board of Trustees of the Leland Stanford Junior University
    Inventors: Charles H. Ahn, Malcolm R. Beasley, Steven J. Benerofe, Martin M. Fejer, Robert H. Hammond, Weizhi Wang