Patents by Inventor Bella Mitchell

Bella Mitchell 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: 7099013
    Abstract: A system and method for detecting an endpoint is disclosed that includes illuminating a first portion of a surface of a wafer with a first broad beam of light. A first reflected spectrum data is received. The first reflected spectrum of data corresponds to a first spectra of light reflected from the first illuminated portion of the surface of the wafer. A second portion of the surface of the wafer with a second broad beam of light. A second reflected spectrum data is received. The second reflected spectrum of data corresponds to a second spectra of light reflected from the second illuminated portion of the surface of the wafer. The first reflected spectrum data is normalized and the second reflected spectrum data is normalized. An endpoint is determined based on a difference between the normalized first spectrum data and the normalized second spectrum data.
    Type: Grant
    Filed: November 24, 2003
    Date of Patent: August 29, 2006
    Assignee: Lam Research Corporation
    Inventors: Vladimir Katz, Bella Mitchell
  • Patent number: 6876455
    Abstract: A method for determining a film thickness in a semiconductor substrate is provided. The method initiates with providing multiple layers on the semiconductor substrate. Then, two reflectance spectra are generated where each of the two reflectance spectra are associated with different time periods while an upper layer is being removed. Next, a difference between the two reflectance spectra is calculated. Then, a curve is defined from the difference between the two reflectance spectra. Next, the defined curve is fitted by a known parametric function to determine the film thickness. An endpoint detector and a CMP system are also provided.
    Type: Grant
    Filed: August 1, 2002
    Date of Patent: April 5, 2005
    Assignee: Lam Research Corporation
    Inventors: Vladimir Katz, Bella Mitchell
  • Patent number: 6806948
    Abstract: A system and method for detecting an endpoint during a chemical mechanical polishing process is disclosed that includes illuminating a first portion of a surface of a wafer with a first broad beam of light. A first reflected spectrum data is received. The first reflected spectrum of data corresponds to a first spectra of light reflected from the first illuminated portion of the surface of the wafer. A second portion of the surface of the wafer with a second broad beam of light. A second reflected spectrum data is received. The second reflected spectrum of data corresponds to a second spectra of light reflected from the second illuminated portion of the surface of the wafer. The first reflected spectrum data is normalized and the second reflected spectrum data is normalized. An endpoint is determined based on a difference between the normalized first spectrum data and the normalized second spectrum data.
    Type: Grant
    Filed: March 29, 2002
    Date of Patent: October 19, 2004
    Assignee: Lam Research Corporation
    Inventors: Vladimir Katz, Bella Mitchell
  • Publication number: 20040165177
    Abstract: A system and method for detecting an endpoint is disclosed that includes illuminating a first portion of a surface of a wafer with a first broad beam of light. A first reflected spectrum data is received. The first reflected spectrum of data corresponds to a first spectra of light reflected from the first illuminated portion of the surface of the wafer. A second portion of the surface of the wafer with a second broad beam of light. A second reflected spectrum data is received. The second reflected spectrum of data corresponds to a second spectra of light reflected from the second illuminated portion of the surface of the wafer. The first reflected spectrum data is normalized and the second reflected spectrum data is normalized. An endpoint is determined based on a difference between the normalized first spectrum data and the normalized second spectrum data.
    Type: Application
    Filed: November 24, 2003
    Publication date: August 26, 2004
    Applicant: LAM RESEARCH
    Inventors: Vladimir Katz, Bella Mitchell
  • Publication number: 20030184732
    Abstract: A system and method for detecting an endpoint during a chemical mechanical polishing process is disclosed that includes illuminating a first portion of a surface of a wafer with a first broad beam of light. A first reflected spectrum data is received. The first reflected spectrum of data corresponds to a first spectra of light reflected from the first illuminated portion of the surface of the wafer. A second portion of the surface of the wafer with a second broad beam of light. A second reflected spectrum data is received. The second reflected spectrum of data corresponds to a second spectra of light reflected from the second illuminated portion of the surface of the wafer. The first reflected spectrum data is normalized and the second reflected spectrum data is normalized. An endpoint is determined based on a difference between the normalized first spectrum data and the normalized second spectrum data.
    Type: Application
    Filed: March 29, 2002
    Publication date: October 2, 2003
    Applicant: LAM RESEARCH
    Inventors: Vladimir Katz, Bella Mitchell