Patents by Inventor Dennis L. Ohren

Dennis L. Ohren 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).

  • On-axis focus sensor and method
    Patent number: 9594230
    Abstract: A focus height sensor in an optical system for inspection of semiconductor devices includes a sensor beam source that emits a beam of electromagnetic radiation. A reflector receives the beam of electromagnetic radiation from the sensor beam source and directs the beam toward a surface of a semiconductor device positioned within a field of view of the optical system. The reflector is positioned to receive at least a portion of the beam back from the surface of the semiconductor device to direct the returned beam to a sensor. The sensor receives the returned beam and outputs a signal correlating to a position of the surface within the field of view along an optical axis of the optical system.
    Type: Grant
    Filed: December 20, 2012
    Date of Patent: March 14, 2017
    Assignee: Rudolph Technologies, Inc.
    Inventors: Dennis L. Ohren, Christopher J. Voges, Andrew E. Rotering
  • ON-AXIS FOCUS SENSOR AND METHOD
    Publication number: 20140368635
    Abstract: A focus height sensor in an optical system for inspection of semiconductor devices includes a sensor beam source that emits a beam of electromagnetic radiation. A reflector receives the beam of electromagnetic radiation from the sensor beam source and directs the beam toward a surface of a semiconductor device positioned within a field of view of the optical system. The reflector is positioned to receive at least a portion of the beam back from the surface of the semiconductor device to direct the returned beam to a sensor. The sensor receives the returned beam and outputs a signal correlating to a position of the surface within the field of view along an optical axis of the optical system.
    Type: Application
    Filed: December 20, 2012
    Publication date: December 18, 2014
    Inventors: Dennis L. Ohren, Christopher J. Voges, Andrew E. Rotering