Patents by Inventor Anh N. Hoang

Anh N. Hoang 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: 7042581
    Abstract: A characteristic of a surface is measured by illuminating the surface with optical radiation over a wide angle and receiving radiation reflected from the surface over an angle that depends on the extend of the illumination angle. An emissivity measurement is made for the surface, and, alternatively, if a reflectivity measurement is made, it becomes more accurate. One application is to measure the thickness of a layer or layers, either a layer made of transparent material or a metal layer. A one or multiple wavelength technique allow very precise measurements of layer thickness. Noise from ambient radiation is minimized by modulating the radiation source at a frequency where such noise is a minimum or non-existent. The measurements may be made during processing of the surface in order to allow precise control of processing semiconductor wafers, flat panel displays, or other articles. A principal application is in situ monitoring of film thickness reduction by chemical-mechanical-polishing (CMP).
    Type: Grant
    Filed: December 15, 2004
    Date of Patent: May 9, 2006
    Assignee: Luxtron Corporation
    Inventors: Charles W. Schietinger, Anh N. Hoang, Dmitry V. Bakin
  • Patent number: 6934040
    Abstract: A characteristic of a surface is measured by illuminating the surface with optical radiation over a wide angle and receiving radiation reflected from the surface over an angle that depends on the extend of the illumination angle. An emissivity measurement is made for the surface, and, alternatively, if a reflectivity measurement is made, it becomes more accurate. One application is to measure the thickness of a layer or layers, either a layer made of transparent material or a metal layer. A one or multiple wavelength technique allow very precise measurements of layer thickness. Noise from ambient radiation is minimized by modulating the radiation source at a frequency where such noise is a minimum or non-existent. The measurements may be made during processing of the surface in order to allow precise control of processing semiconductor wafers, flat panel displays, or other articles. A principal application is in situ monitoring of film thickness reduction by chemical-mechanical-polishing (CMP).
    Type: Grant
    Filed: September 26, 2003
    Date of Patent: August 23, 2005
    Assignee: Luxtron Corporation
    Inventors: Charles W. Schietinger, Anh N. Hoang, Dmitry V. Bakin
  • Patent number: 6654132
    Abstract: A characteristic of a surface is measured by illuminating the surface with optical radiation over a wide angle and receiving radiation reflected from the surface over an angle that depends on the extend of the illumination angle. An emissivity measurement is made for the surface, and, alternatively, if a reflectivity measurement is made, it becomes more accurate. One application is to measure the thickness of a layer or layers, either a layer made of transparent material or a metal layer. A one or multiple wavelength technique allow very precise measurements of layer thickness. Noise from ambient radiation is minimized by modulating the radiation source at a frequency where such noise is a minimum or non-existent. The measurements may be made during processing of the surface in order to allow precise control of processing semiconductor wafers, flat panel displays, or other articles. A principal application is in situ monitoring of film thickness reduction by chemical-mechanical-polishing (CMP).
    Type: Grant
    Filed: May 24, 2000
    Date of Patent: November 25, 2003
    Assignee: Luxtron Corporation
    Inventors: Charles W. Schietinger, Anh N. Hoang, Dmitry V. Bakin
  • Publication number: 20030206573
    Abstract: A temperature sensor utilizing optical temperature measuring techniques is constructed to make firm contact with a surface whose temperature is being measured, an example application being the monitoring of semiconductor wafers or flat panel displays while being processed. A cap is mounted near but spaced apart from an end of a lightwave guide, with a resilient element that applies force of the cap against a surface whose temperature is being measured as the cap is urged toward the optical fiber end. An optical temperature sensing element, such as luminescent material or a surface of known emissivity, is carried within the cap. A bellows with a closed end conveniently serves as both the cap and the resilient element. An alternative temperature measuring device installs an optical temperature sensing material within a test substrate behind an optical window, and then views the sensing material through the window.
    Type: Application
    Filed: May 30, 2003
    Publication date: November 6, 2003
    Inventors: John P. Gotthold, Anh N. Hoang, Surinder S. Sandhu, John Leonard Shaver, Terry M. Stapleton
  • Patent number: 6572265
    Abstract: A temperature sensor utilizing optical temperature measuring techniques is constructed to make firm contact with a surface whose temperature is being measured, an example application being the monitoring of semiconductor wafers or flat panel displays while being processed. A cap is mounted near but spaced apart from an end of a lightwave guide, with a resilient element that applies force of the cap against a surface whose temperature is being measured as the cap is urged toward the optical fiber end. An optical temperature sensing element, such as luminescent material or a surface of known emissivity, is carried within the cap. A bellows with a closed end conveniently serves as both the cap and the resilient element. An alternative temperature measuring device installs an optical temperature sensing material within a test substrate behind an optical window, and then views the sensing material through the window.
    Type: Grant
    Filed: April 20, 2001
    Date of Patent: June 3, 2003
    Assignee: Luxtron Corporation
    Inventors: John P. Gotthold, Anh N. Hoang, Surinder S. Sandhu, John Leonard Shaver, Terry M. Stapleton
  • Patent number: 5860972
    Abstract: The present invention relates generally to methods and devices for detecting, destroying and removing urinary calculi and other similar structures anywhere within an animal body, and more specifically to a method for locating such structures, fragmenting and vaporizing them and related detection and control schemes.
    Type: Grant
    Filed: October 26, 1995
    Date of Patent: January 19, 1999
    Assignee: Xintec Corporation
    Inventor: Anh N. Hoang
  • Patent number: 5689520
    Abstract: Variable waveform output in surgical laser is achieved by controlling power into a solid-state laser cavity. A control circuit is used to coordinate pulse energy, pulse frequency, and pulsewidth into a solid-state laser cavity to achieve a user desired waveform output. An Insulated Gate Bipolar Transistor (IGBT) or similar solid-state transistor switching device under the direction of a control circuit is used to switch energy into the solid-state laser cavity thereby modulating the pulse frequency and pulsewidth. The pulse energy is varied by varying the charge across the capacitor bank which sends energy through the IGBT to the solid-state laser cavity. By having the ability to vary the laser's output pulse frequency, pulsewidth, and pulse energy, multiple tissue effects can be achieved using one solid-state laser cavity.
    Type: Grant
    Filed: October 31, 1995
    Date of Patent: November 18, 1997
    Assignee: Xintec Corporation
    Inventor: Anh N. Hoang