Patents by Inventor Robert J. Horrell

Robert J. Horrell 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).

  • Methods for optical endpoint detection during semiconductor wafer polishing
    Patent number: 7549909
    Abstract: A method of measuring a change in thickness of a layer of material disposed on a wafer while polishing the layer. Light is directed at the surface of the wafer from an optical sensor disposed within the polishing pad. The intensity of the reflected light is measured by a light detector also disposed in the polishing pad. The intensity of the reflected light varies sinusoidally with the change in layer thickness as the layer is removed. By measuring the absolute thickness of the layer at two or more points along the sinusoidal curve, the sinusoidal curve is calibrated so that a portion of the wavelength of the curve corresponds to a change in thickness of the layer.
    Type: Grant
    Filed: June 26, 2007
    Date of Patent: June 23, 2009
    Assignee: Strasbaugh
    Inventors: Alice Madrone Dalrymple, Robert J. Horrell
  • Devices and methods for optical endpoint detection during semiconductor wafer polishing
    Patent number: 7235154
    Abstract: A method of measuring a change in thickness of a layer of material disposed on a wafer while polishing the layer. Light is directed at the surface of the wafer from an optical sensor disposed within the polishing pad. The intensity of the reflected light is measured by a light detector also disposed in the polishing pad. The intensity of the reflected light varies sinusoidally with the change in layer thickness as the layer is removed. By measuring the absolute thickness of the layer at two or more points along the sinusoidal curve, the sinusoidal curve is calibrated so that a portion of the wavelength of the curve corresponds to a change in thickness of the layer.
    Type: Grant
    Filed: January 8, 2004
    Date of Patent: June 26, 2007
    Assignee: Strasbaugh
    Inventors: Alice Madrone Dalrymple, Robert J. Horrell