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: 7006541Abstract: 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: GrantFiled: January 29, 2003Date of Patent: February 28, 2006Assignee: Lambda Physik AGInventors: Peter Lokai, Thomas Schroeder, Juergen Kleinschmidt, Uwe Stamm, Klaus Wolfgang Vogler
-
Patent number: 6856638Abstract: 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: GrantFiled: October 19, 2001Date of Patent: February 15, 2005Assignee: Lambda Physik AGInventors: Konstantin Aab, Juergen Kleinschmidt, Peter Lokai, Matthias Ulrich
-
Patent number: 6839375Abstract: 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: GrantFiled: September 4, 2002Date of Patent: January 4, 2005Assignee: Lambda Physik AGInventors: Peter Lokai, Farid Seddighi
-
Patent number: 6792023Abstract: 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: GrantFiled: March 28, 2002Date of Patent: September 14, 2004Assignee: Lambda Physik AGInventors: Juergen Kleinschmidt, Peter Lokai, Konstantin Aab
-
Patent number: 6717973Abstract: 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: GrantFiled: June 13, 2001Date of Patent: April 6, 2004Assignee: Lambda Physik AGInventors: Dirk Basting, Sergei Govorkov, Juergen Kleinschmidt, Peter Lokai, Uwe Stamm
-
Publication number: 20030210715Abstract: 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: ApplicationFiled: January 29, 2003Publication date: November 13, 2003Applicant: Lambda Physik AG.Inventors: Peter Lokai, Thomas Schroeder, Juergen Kleinschmidt, Uwe Stamm, Klaus Wolfgang Vogler
-
Publication number: 20030161374Abstract: 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: ApplicationFiled: November 12, 2002Publication date: August 28, 2003Applicant: Lambda Physik AGInventor: Peter Lokai
-
Patent number: 6608848Abstract: 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: GrantFiled: May 4, 2001Date of Patent: August 19, 2003Assignee: Lambda Physik AGInventors: Jürgen Kleinschmidt, Uwe Stamm, Klaus Vogler, Peter Lokai
-
Patent number: 6580517Abstract: 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: GrantFiled: February 22, 2001Date of Patent: June 17, 2003Assignee: Lambda Physik AGInventors: Peter Lokai, Thomas Schroeder
-
Patent number: 6567451Abstract: 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: GrantFiled: March 15, 2002Date of Patent: May 20, 2003Assignee: Lambda Physik AGInventors: Juergen Kleinschmidt, Peter Lokai
-
Patent number: 6553050Abstract: 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: GrantFiled: February 21, 2002Date of Patent: April 22, 2003Assignee: Lambda Physik AGInventors: Juergen Kleinschmidt, Peter Lokai
-
Patent number: 6516012Abstract: 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: GrantFiled: March 15, 2002Date of Patent: February 4, 2003Assignee: Lambda Physik AGInventors: Juergen Kleinschmidt, Peter Lokai
-
Publication number: 20020141474Abstract: 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: ApplicationFiled: March 15, 2002Publication date: October 3, 2002Inventors: Juergen Kleinschmidt, Peter Lokai
-
Publication number: 20020141471Abstract: 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: ApplicationFiled: October 19, 2001Publication date: October 3, 2002Applicant: Lambda Physik AGInventors: Konstantin Aab, Juergen Kleinschmidt, Peter Lokai, Matthias Ulrich
-
Publication number: 20020122452Abstract: 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: ApplicationFiled: March 15, 2002Publication date: September 5, 2002Applicant: Lambda Physik AG.,Inventors: Juergen Kleinschmidt, Peter Lokai
-
Patent number: 6421365Abstract: 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: GrantFiled: November 17, 2000Date of Patent: July 16, 2002Assignee: Lambda Physik AGInventors: Juergen Kleinschmidt, Peter Lokai
-
Publication number: 20020018505Abstract: 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: ApplicationFiled: June 13, 2001Publication date: February 14, 2002Applicant: Lambda Physik AGInventors: Dirk Basting, Sergei Govorkov, Juergen Kleinschmidt, Peter Lokai, Uwe Stamm
-
Publication number: 20020012368Abstract: 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: ApplicationFiled: May 4, 2001Publication date: January 31, 2002Applicant: Lambda Physik AGInventors: Jurgen Kleinschmidt, Uwe Stamm, Klaus Vogler, Peter Lokai
-
Publication number: 20020003817Abstract: 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: ApplicationFiled: February 22, 2001Publication date: January 10, 2002Inventors: Peter Lokai, Thomas Schroeder
-
Patent number: 6272158Abstract: 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: GrantFiled: October 4, 2000Date of Patent: August 7, 2001Assignee: Lambda Physik AGInventors: Jürgen Kleinschmidt, Uwe Stamm, Klaus Vogler, Peter Lokai