Patents by Inventor Peter Lokai

Peter Lokai 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: 7006541
    Abstract: A tunable laser system includes a gain medium and an optical resonator for generating a laser beam, and a spectral narrowing and tuning unit within the resonator. A detection and control unit controls a relative wavelength of the laser system. A wavelength calibration module calibrates the detection and control unit. The module contains more than one species each having an optical transition line within the tuning spectrum of the laser. A beam portion of the narrowed emission from the laser is directed through the wavelength calibration module and a beam portion is directed through the detection and control unit when the laser beam is scanned through the optical transition line of each of the species within the module. The detection and control unit is monitored and calibrated during the scanning.
    Type: Grant
    Filed: January 29, 2003
    Date of Patent: February 28, 2006
    Assignee: Lambda Physik AG
    Inventors: Peter Lokai, Thomas Schroeder, Juergen Kleinschmidt, Uwe Stamm, Klaus Wolfgang Vogler
  • Patent number: 6856638
    Abstract: A line-narrowed excimer or molecular fluorine laser system includes a discharge chamber filled with a gas mixture at least including molecular fluorine and a buffer gas, multiple electrodes within the discharge chamber connected to a discharge circuit for energizing the gas mixture, a resonator including a pair of resonator reflecting surfaces disposed on either side of the discharge chamber for generating a laser beam, and a line-narrowing/selection unit within the resonator for narrowing the bandwidth of the laser beam. The resonator further includes a third reflecting surface which is deformable and disposed between the pair of resonator reflecting surfaces. The line-narrowing/selection unit preferably includes a beam expander and a dispersive element, wherein the deformable third reflecting surface is disposed between the beam expander and the dispersive element.
    Type: Grant
    Filed: October 19, 2001
    Date of Patent: February 15, 2005
    Assignee: Lambda Physik AG
    Inventors: Konstantin Aab, Juergen Kleinschmidt, Peter Lokai, Matthias Ulrich
  • Patent number: 6839375
    Abstract: Some of the key optical components of lithography lasers are very sensitive to intensive UV radiation. Intensive UV radiation can cause color center formation in these components. The color centers are reason for laser energy dropping, worse laser-bandwidth and limited life-time. The on-line monitoring of the color-center formation during operation of the lithography lasers detecting laser induced fluorescence and investigation of the fluorescence spectrum can be helpful for maintenance of lithography lasers. The fluorescence signal is analyzed and delivers information about optics quality.
    Type: Grant
    Filed: September 4, 2002
    Date of Patent: January 4, 2005
    Assignee: Lambda Physik AG
    Inventors: Peter Lokai, Farid Seddighi
  • Patent number: 6792023
    Abstract: An excimer or molecular fluorine laser system includes a laser chamber filled with a gas mixture at least including a halogen-containing species and a buffer gas, multiple electrodes, including a pair of main discharge electrodes and at least one preionization electrode, within the laser chamber and connected to a discharge circuit for energizing the gas mixture, and a resonator including a line-narrowing and/or selection module for generating a laser beam at high spectral purity.
    Type: Grant
    Filed: March 28, 2002
    Date of Patent: September 14, 2004
    Assignee: Lambda Physik AG
    Inventors: Juergen Kleinschmidt, Peter Lokai, Konstantin Aab
  • Patent number: 6717973
    Abstract: A F2-laser includes a discharge chamber filled with a gas mixture including molecular fluorine for generating a spectral emission in a wavelength range between 157 nm and 158 nm including a primary line and a secondary line, multiple electrodes coupled with a power supply circuit for producing a pulsed discharge to energize the molecular fluorine, a resonator including the discharge chamber and an interferometric device for generating a laser beam having a bandwidth of less than 1 pm, and a wavelength monitor coupled in a feedback loop with a processor for monitoring a spectral distribution of the laser beam. The processor controls an interferometric spectrum of the interferometric device based on the monitored spectral distribution such that sidebands within the spectral distribution are substantially minimized.
    Type: Grant
    Filed: June 13, 2001
    Date of Patent: April 6, 2004
    Assignee: Lambda Physik AG
    Inventors: Dirk Basting, Sergei Govorkov, Juergen Kleinschmidt, Peter Lokai, Uwe Stamm
  • Publication number: 20030210715
    Abstract: A tunable laser system includes a gain medium and an optical resonator for generating a laser beam, and a spectral narrowing and tuning unit within the resonator. A detection and control unit controls a relative wavelength of the laser system. A wavelength calibration module calibrates the detection and control unit. The module contains more than one species each having an optical transition line within the tuning spectrum of the laser.
    Type: Application
    Filed: January 29, 2003
    Publication date: November 13, 2003
    Applicant: Lambda Physik AG.
    Inventors: Peter Lokai, Thomas Schroeder, Juergen Kleinschmidt, Uwe Stamm, Klaus Wolfgang Vogler
  • Publication number: 20030161374
    Abstract: A spectrometer based on a high-resolution confocal Fabry-Perot interferometer for detection of wavelength, FWHM and/or 95% bandwidth of a laser beam of a narrow band tunable excimer or molecular fluorine lithography laser, or EUV generating source, preferably includes a reduction telescope for reducing the laser beam, a diffusor to homogenize the incident excimer or molecular fluorine lithography laser beam, a housing for mounting the confocal Fabry-Perot interferometer between windows in a sealed and temperature-stabilized housing, imaging optics for bringing the incident beam to focus at approximately a center of the interferometer, interferometer fringe imaging optics, and a photoelectric detector of the interferometer fringe image.
    Type: Application
    Filed: November 12, 2002
    Publication date: August 28, 2003
    Applicant: Lambda Physik AG
    Inventor: Peter Lokai
  • Patent number: 6608848
    Abstract: A wavelength calibration system determines an absolute wavelength of a narrowed spectral emission band of an excimer or molecular laser system. The system includes a module including an element which optically interacts with a component of an output beam of the laser within the tunable range of the laser system around the narrowed band. An inter-level resonance is detected by monitoring changes in voltage within the module, or photo-absorption is detected by photodetecting equipment. The absolute wavelength of the narrowed band is precisely determinable when the optical transitions occur and are detected. When the system specifically includes an ArF-excimer laser chamber, the module is preferably a galvatron containing an element that photo-absorbs around 193 nm and the element is preferably a gas or vapor selected from the group consisting of arsenic, carbon, oxygen, iron, gaseous hydrocarbons, halogenized hydrocarbons, carbon-contaminated inert gases, germanium and platinum vapor.
    Type: Grant
    Filed: May 4, 2001
    Date of Patent: August 19, 2003
    Assignee: Lambda Physik AG
    Inventors: Jürgen Kleinschmidt, Uwe Stamm, Klaus Vogler, Peter Lokai
  • Patent number: 6580517
    Abstract: A tunable laser system includes a gain medium and an optical resonator for generating a laser beam, and a spectral narrowing and tuning unit within the resonator. A detection and control unit controls a relative wavelength of the laser system. A wavelength calibration module calibrates the detection and control unit. The module contains more than one species each having an optical transition line within the tuning spectrum of the laser. A beam portion of the narrowed emission from the laser is directed through the wavelength calibration module and a beam portion is directed through the detection and control unit when the laser beam is scanned through the optical transition line of each of the species within the module. The detection and control unit is monitored and calibrated during the scanning.
    Type: Grant
    Filed: February 22, 2001
    Date of Patent: June 17, 2003
    Assignee: Lambda Physik AG
    Inventors: Peter Lokai, Thomas Schroeder
  • Patent number: 6567451
    Abstract: An excimer or molecular fluorine laser includes a discharge chamber filled with a gas mixture, multiple electrodes within the discharge chamber connected to a power supply circuit for energizing the gas mixture, and a resonator including the discharge chamber and a pair of resonator reflectors for generating an output laser beam. One of the resonator reflectors is an output coupling interferometer including a pair of opposing reflecting surfaces tuned to produce a reflectivity maximum at a selected wavelength for narrowing a linewidth of the output laser beam. One of the pair of opposing reflecting surfaces is configured such that the opposing reflecting surfaces of the interferometer have a varying optical distance therebetween over an incident beam cross-section which serves to suppress outer portions of the reflectivity maximum to reduce spectral purity.
    Type: Grant
    Filed: March 15, 2002
    Date of Patent: May 20, 2003
    Assignee: Lambda Physik AG
    Inventors: Juergen Kleinschmidt, Peter Lokai
  • Patent number: 6553050
    Abstract: An excimer or molecular fluorine laser includes a discharge chamber filled with a gas mixture, multiple electrodes within the discharge chamber connected to a power supply circuit for energizing the gas mixture, and a resonator including the discharge chamber and a pair of resonator reflectors for generating an output laser beam. The resonator includes an interferometric device, which may be a resonator reflector such as an output coupling interferometer or HR reflector, or a transmissive intracavity component, including a pair of opposing reflecting surfaces tuned to produce a response maximum at a selected wavelength for narrowing a linewidth of the output laser beam. One of the pair of opposing reflecting surfaces is preferably configured such that the opposing reflecting surfaces of the interferometer have a varying optical distance therebetween over an incident beam cross-section which serves to suppress at least one side band or outer portions of the response maximum to reduce spectral purity.
    Type: Grant
    Filed: February 21, 2002
    Date of Patent: April 22, 2003
    Assignee: Lambda Physik AG
    Inventors: Juergen Kleinschmidt, Peter Lokai
  • Patent number: 6516012
    Abstract: An excimer or molecular fluorine laser includes a discharge chamber filled with a gas mixture, multiple electrodes within the discharge chamber connected to a power supply circuit for energizing the gas mixture, and a resonator including the discharge chamber and a pair of resonator reflectors for generating an output laser beam. One of the resonator reflectors is an output coupling interferometer including a pair of opposing reflecting surfaces tuned to produce a reflectivity maximum at a selected wavelength for narrowing a linewidth of the output laser beam. One of the pair of opposing reflecting surfaces is configured such that the opposing reflecting surfaces of the interferometer have a varying optical distance therebetween over an incident beam cross-section which serves to suppress outer portions of the reflectivity maximum to reduce spectral purity.
    Type: Grant
    Filed: March 15, 2002
    Date of Patent: February 4, 2003
    Assignee: Lambda Physik AG
    Inventors: Juergen Kleinschmidt, Peter Lokai
  • Publication number: 20020141474
    Abstract: An excimer or molecular fluorine laser includes a discharge chamber filled with a gas mixture, multiple electrodes within the discharge chamber connected to a power supply circuit for energizing the gas mixture, and a resonator including the discharge chamber and a pair of resonator reflectors for generating an output laser beam. One of the resonator reflectors is an output coupling interferometer including a pair of opposing reflecting surfaces tuned to produce a reflectivity maximum at a selected wavelength for narrowing a linewidth of the output laser beam. One of the pair of opposing reflecting surfaces is configured such that the opposing reflecting surfaces of the interferometer have a varying optical distance therebetween over an incident beam cross-section which serves to suppress outer portions of the reflectivity maximum to reduce spectral purity.
    Type: Application
    Filed: March 15, 2002
    Publication date: October 3, 2002
    Inventors: Juergen Kleinschmidt, Peter Lokai
  • Publication number: 20020141471
    Abstract: A line-narrowed excimer or molecular fluorine laser system includes a discharge chamber filled with a gas mixture at least including molecular fluorine and a buffer gas, multiple electrodes within the discharge chamber connected to a discharge circuit for energizing the gas mixture, a resonator including a pair of resonator reflecting surfaces disposed on either side of the discharge chamber for generating a laser beam, and a line-narrowing/selection unit within the resonator for narrowing the bandwidth of the laser beam. The resonator further includes a third reflecting surface which is deformable and disposed between the pair of resonator reflecting surfaces. The line-narrowing/selection unit preferably includes a beam expander and a dispersive element, wherein the deformable third reflecting surface is disposed between the beam expander and the dispersive element.
    Type: Application
    Filed: October 19, 2001
    Publication date: October 3, 2002
    Applicant: Lambda Physik AG
    Inventors: Konstantin Aab, Juergen Kleinschmidt, Peter Lokai, Matthias Ulrich
  • Publication number: 20020122452
    Abstract: An excimer or molecular fluorine laser includes a discharge chamber filled with a gas mixture, multiple electrodes within the discharge chamber connected to a power supply circuit for energizing the gas mixture, and a resonator including the discharge chamber and a pair of resonator reflectors for generating an output laser beam. One of the resonator reflectors is an output coupling interferometer including a pair of opposing reflecting surfaces tuned to produce a reflectivity maximum at a selected wavelength for narrowing a linewidth of the output laser beam. One of the pair of opposing reflecting surfaces is configured such that the opposing reflecting surfaces of the interferometer have a varying optical distance therebetween over an incident beam cross-section which serves to suppress outer portions of the reflectivity maximum to reduce spectral purity.
    Type: Application
    Filed: March 15, 2002
    Publication date: September 5, 2002
    Applicant: Lambda Physik AG.,
    Inventors: Juergen Kleinschmidt, Peter Lokai
  • Patent number: 6421365
    Abstract: An excimer or molecular fluorine laser includes a discharge chamber filled with a gas mixture, multiple electrodes within the discharge chamber connected to a power supply circuit for energizing the gas mixture, and a resonator including the discharge chamber and a pair of resonator reflectors for generating an output laser beam. One of the resonator reflectors is an output coupling interferometer including a pair of opposing reflecting surfaces tuned to produce a reflectivity maximum at a selected wavelength for narrowing a linewidth of the output laser beam. One of the pair of opposing reflecting surfaces is configured such that the opposing reflecting surfaces of the interferometer have a varying optical distance therebetween over an incident beam cross-section which serves to suppress outer portions of the reflectivity maximum to reduce spectral purity.
    Type: Grant
    Filed: November 17, 2000
    Date of Patent: July 16, 2002
    Assignee: Lambda Physik AG
    Inventors: Juergen Kleinschmidt, Peter Lokai
  • Publication number: 20020018505
    Abstract: A F2-laser includes a discharge chamber filled with a gas mixture including molecular fluorine for generating a spectral emission in a wavelength range between 157 nm and 158 nm including a primary line and a secondary line, multiple electrodes coupled with a power supply circuit for producing a pulsed discharge to energize the molecular fluorine, a resonator including the discharge chamber and an interferometric device for generating a laser beam having a bandwidth of less than 1 pm, and a wavelength monitor coupled in a feedback loop with a processor for monitoring a spectral distribution of the laser beam. The processor controls an interferometric spectrum of the interferometric device based on the monitored spectral distribution such that sidebands within the spectral distribution are substantially minimized.
    Type: Application
    Filed: June 13, 2001
    Publication date: February 14, 2002
    Applicant: Lambda Physik AG
    Inventors: Dirk Basting, Sergei Govorkov, Juergen Kleinschmidt, Peter Lokai, Uwe Stamm
  • Publication number: 20020012368
    Abstract: A wavelength calibration system determines an absolute wavelength of a narrowed spectral emission band of an excimer or molecular laser system. The system includes a module including an element which optically interacts with a component of an output beam of the laser within the tunable range of the laser system around the narrowed band. An inter-level resonance is detected by monitoring changes in voltage within the module, or photo-absorption is detected by photodetecting equipment. The absolute wavelength of the narrowed band is precisely determinable when the optical transitions occur and are detected. When the system specifically includes an ArF-excimer laser chamber, the module is preferably a galvatron containing an element that photo-absorbs around 193 nm and the element is preferably a gas or vapor selected from the group consisting of arsenic, carbon, oxygen, iron, gaseous hydrocarbons, halogenized hydrocarbons, carbon-contaminated inert gases, germanium and platinum vapor.
    Type: Application
    Filed: May 4, 2001
    Publication date: January 31, 2002
    Applicant: Lambda Physik AG
    Inventors: Jurgen Kleinschmidt, Uwe Stamm, Klaus Vogler, Peter Lokai
  • Publication number: 20020003817
    Abstract: A tunable laser system includes a gain medium and an optical resonator for generating a laser beam, and a spectral narrowing and tuning unit within the resonator. A detection and control unit controls a relative wavelength of the laser system. A wavelength calibration module calibrates the detection and control unit. The module contains more than one species each having an optical transition line within the tuning spectrum of the laser. A beam portion of the narrowed emission from the laser is directed through the wavelength calibration module and a beam portion is directed through the detection and control unit when the laser beam is scanned through the optical transition line of each of the species within the module. The detection and control unit is monitored and calibrated during the scanning.
    Type: Application
    Filed: February 22, 2001
    Publication date: January 10, 2002
    Inventors: Peter Lokai, Thomas Schroeder
  • Patent number: 6272158
    Abstract: A wavelength calibration system determines an absolute wavelength of a narrowed spectral emission band of an excimer or molecular laser system. The system includes a module including an element which optically interacts with a component of an output beam of the laser within the tunable range of the laser system around the narrowed band. An inter-level resonance is detected by monitoring changes in voltage within the module, or photo-absorption is detected by photodetecting equipment. The absolute wavelength of the narrowed band is precisely determinable when the optical transitions occur and are detected. When the system specifically includes an ArF-excimer laser chamber, the module is preferably a galvatron containing an element that photo-absorbs around 193 nm and the element is preferably a gas or vapor selected from the group consisting of arsenic, carbon, oxygen, iron, gaseous hydrocarbons, halogenized hydrocarbons, carbon-contaminated inert gases, germanium and platinum vapor.
    Type: Grant
    Filed: October 4, 2000
    Date of Patent: August 7, 2001
    Assignee: Lambda Physik AG
    Inventors: Jürgen Kleinschmidt, Uwe Stamm, Klaus Vogler, Peter Lokai