Patents by Inventor Oliver C. Wells

Oliver C. Wells 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: 6768111
    Abstract: A method of measurement of topographic features on a surface of a substrate is presented, wherein a focused beam of particles falls onto the surface of the substrate, and backscattered particles are detected with a particle detector. An opaque material is interposed between the surface and the detector, and the position of the shadow of an edge of the opaque material on the detector is recorded. The relative position of the edge and the surface of the substrate is then determined, and the topography of the surface determined as the particle beam and the substrate are moved with respect to one another.
    Type: Grant
    Filed: September 16, 2003
    Date of Patent: July 27, 2004
    Assignee: International Business Machines Corp.
    Inventors: Oliver C. Wells, Lynne M. Gignac, Jonathan L. Rullan, Conal E. Murray
  • Patent number: 5408098
    Abstract: A detector system for a low-loss electron operated scanning electron microscope providing a focused primary electron beam and producing backscattered electrons having a plurality of energy levels by interactions with a specimen disposed within the primary electron beam includes a plurality of grids, each of the grids having a corresponding predetermined potential, wherein the grids selectively filter the backscattered electrons to permit collection of low loss electrons having at least a predetermined threshold energy level at an exit side of the grids, a focusing grid disposed opposing the exit side of the grids for focusing the low loss electrons to produce convergence of the low loss electrons in a convergence region and an electron detector located substantially within the convergence region for detecting the low loss electrons. Both the electron detector and the focusing grids are maintained at predetermined detector and focusing potentials, which can be made equal to one another.
    Type: Grant
    Filed: September 10, 1993
    Date of Patent: April 18, 1995
    Assignee: International Business Machines Corporation
    Inventor: Oliver C. Wells
  • Patent number: 5047649
    Abstract: A method and apparatus for producing fine line patterns on insulating surfaces utilizing a conductive spring-like cantilever having a pointed tip which is in proximity to the surface to be affected. Electrons emitted from the tip travel toward the insulator surface and cause changes therein or affect molecules located in the proximity of the insulator surface. Tunneling current is not required, and a highly conducting return current path for electrons through the insulator is not necessary. The incident electrons can be used to provide patterned, narrow-width features either by deposition of a material onto the insulator surface, or by producing etching in localized regions of the insulator surface, or by changing the insulator surface so that it can be etched.
    Type: Grant
    Filed: October 9, 1990
    Date of Patent: September 10, 1991
    Assignee: International Business Machines Corporation
    Inventors: Rodney T. Hodgson, Jackson E. Stanland, Oliver C. Wells
  • Patent number: 4962306
    Abstract: An electron microscope which includes a detector which is located in the magnetic field used to focus the primary electron beam onto the sample. The focusing magnetic field is used to energy-filter and/or energy analyze the scattered electrons without the need for additional equipment, such as a retarding-field energy filter. The magnetic field of the condenser-objective lens (or of any other type of magnetic lens) of the microscope provides the filtering and/or analyzing action, and the detector can be located so as to collect only low-loss electrons.
    Type: Grant
    Filed: December 4, 1989
    Date of Patent: October 9, 1990
    Assignee: Intenational Business Machines Corporation
    Inventors: Rodney T. Hodgson, Francoise K. LeGoues, Oliver C. Wells
  • Patent number: 4785189
    Abstract: An electron sensitive surface is patternized treated to a high resolution pattern of low-energy electrons without any need to do focussing by emitting the low-energy electrons from a pointed electrode and positioning the apex of the pointed electron emitting source suitably close to the surface being treated.
    Type: Grant
    Filed: February 19, 1988
    Date of Patent: November 15, 1988
    Assignee: International Business Machines Corporation
    Inventor: Oliver C. Wells
  • Patent number: 4665313
    Abstract: An improved electron bombardment induced conductivity apparatus and method is described for charge collection imaging of semiconductor materials and devices with unprecedented resolution. This is accomplished by bombarding a very small area of the surface of a specimen with low-energy electrons rather than high-energy electrons and by physically scanning (i.e. moving) the electron source itself (rather than only the beam of electrons) with respect to the specimen. A very small area of the specimen surface is bombarded with low-energy electrons without any need to do focussing by emitting the low-energy electrons from a sharply pointed electrode positioned very close to the surface being bombarded with the low-energy electrons. Hole-electron pairs created by the electron bombardment are sensed (preferably collected by an electric field) and a measurement of the sensed number of such pairs is displayed in synchronism with the electrode scanning to produce a charge collection image of the specimen.
    Type: Grant
    Filed: June 28, 1985
    Date of Patent: May 12, 1987
    Assignee: International Business Machines Corporation
    Inventor: Oliver C. Wells
  • Patent number: 4618767
    Abstract: Low-energy scanning transmission electron microscopy is achieved by using a sharply pointed electrode as a source of electrons having energies less than 10 eV and scanning the electron emitting pointed source across the surface of a self-supported thin film of material to be investigated at an essentially constant distance on the order of nanometers. The electrons transmitted through the specimen are sensed by a suitable detector and the output signal of the detector is used to control a display unit, such as a CRT display or a plotter. A scanning signal generating means simultaneously controls both the scanning of the electron emitting point source and the display unit while a separation control unit holds the distance between the point source and surface at a constant value. The electron emitting point source and associated mechanical drives as well as the specimen film and electron detector are all positioned in a vacuum chamber and isolated from vibration by a damped suspension apparatus.
    Type: Grant
    Filed: March 22, 1985
    Date of Patent: October 21, 1986
    Assignee: International Business Machines Corporation
    Inventors: David A. Smith, Oliver C. Wells