Patents Assigned to Lambda Physik AG
  • Patent number: 6862307
    Abstract: Method and system for providing an excimer or molecular fluorine laser including a laser tube filled with a laser gas surrounded by an optical resonator, where the laser tube has multiple electrodes including a pair of main discharge electrodes connected to a discharge circuit for exciting the laser gas to produce a laser output beam. The discharge circuit has an all solid state switch and preferably does not include a transformer. The solid state switch includes multiple solid state devices that may be capable of switching voltages in excess of 12 kV, such as 14-32 kV or more, or the voltage needed to switch the laser. The series of switches has a rise time of approximately less than 300 ns, and preferably around 100 ns or less. The switch may be capable of switching voltages of slightly more than half, but less than the entire voltage needed to produce laser pulses of desired energies, and a voltage doubling circuit may be used to produce the voltage required to produce the desired output pulse energies.
    Type: Grant
    Filed: May 14, 2001
    Date of Patent: March 1, 2005
    Assignee: Lambda Physik AG
    Inventors: Rustem Osmanow, Uwe Stamm, Andreas Targsdorg
  • 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: 6847671
    Abstract: A tangential blower for use in a gas discharge laser is provided provides improved homogeneity of laser gas flow through the discharge region of the laser. A flange which supports adjacent blower sections has an aerodynamic shape and occupies a minimal portion of the space in the inlet region of the blowers. The ends of the blower's shafts may be formed as a twice-profiled polygon which is has a non-uniform and preferably rounded geometry along its longitudinal axis where it fits into end flanges. The blades of the blower may be formed with varying thickness and radii of curvature. The blower's blades and hubs may be cast as a single piece of steel, titanium alloy, or other suitable material.
    Type: Grant
    Filed: March 29, 2001
    Date of Patent: January 25, 2005
    Assignee: Lambda Physik AG
    Inventor: Juergen Baumler
  • 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: 6834069
    Abstract: A F2 laser includes a laser tube filled with a laser gas mixture at least including molecular fluorine for generating a spectral emission including multiple closely-spaced lines in a wavelength range between 157 nm and 158 nm, including a first line centered around 157.62 nm and a second line centered around 157.52 nm, multiple electrodes within the discharge chamber connected with a power supply circuit for energizing the molecular fluorine, a laser resonator including a line selection unit for selecting one of the first and second lines of the multiple closely spaced lines and for supressing the other of the first and second lines, for generating a narrow bandwidth VUV output beam, and at least one intracavity polarizing element. The narrow bandwidth VUV output beam is polarized at least 95%, and may be 98% or more.
    Type: Grant
    Filed: June 3, 2002
    Date of Patent: December 21, 2004
    Assignee: Lambda Physik AG
    Inventors: Elko Bergmann, Frank Voss, Klaus Wolfgang Vogler
  • Patent number: 6834066
    Abstract: Method and system for providing stabilization techniques for high repetition rate gas discharge lasers with active loads provided in the discharge circuitry design which may include a resistance provided in the discharge circuitry.
    Type: Grant
    Filed: April 18, 2001
    Date of Patent: December 21, 2004
    Assignee: Lambda Physik AG
    Inventors: Igor Bragin, Vadim Berger, Juergen Kleinschmidt
  • Publication number: 20040252740
    Abstract: A method and apparatus is provided for stabilizing output beam parameters of a gas discharge laser by maintaining a molecular fluorine component of the laser gas mixture at a predetermined partial pressure using a gas supply unit and a processor. The molecular fluorine is provided at an initial partial pressure and is subject to depletion within the laser discharge chamber. Injections of gas including molecular fluorine are performed each to increase the partial pressure of molecular fluorine by a selected amount in the laser chamber preferably less than 0.2 mbar per injection, or 7% of an amount of F2 already within the laser chamber. A number of successive injections may be performed at selected intervals to maintain the constituent gas substantially at the initial partial pressure for maintaining stable output beam parameters.
    Type: Application
    Filed: January 6, 2003
    Publication date: December 16, 2004
    Applicant: Lambda Physik AG.
    Inventors: Hans-Stephan Albrecht, Klaus Wolfgang Vogler, Juergen Kleinschmidt, Thomas Schroeder, Igor Bragin, Vadim Berger, Uwe Stamm, Wolfgang Zschocke, Sergei Govorkov
  • Patent number: 6822977
    Abstract: A lithography laser system for incorporating with a semiconductor processing system includes a discharge chamber filled with a laser gas including molecular fluorine and a buffer gas, multiple electrodes within the discharge chamber and connected with a discharge circuit for energizing the laser gas, a resonator including the discharge chamber for generating a laser beam, and a processor. The processor runs an energy control algorithm and sends a signal to the discharge circuit based on said algorithm to apply electrical pulses to the electrodes so that the laser beam exiting the laser system has a specified first energy distribution over a group of pulses. The energy control algorithm is based upon a second energy distribution previously determined of a substantially same pattern of pulses as the group of pulses having the first energy distribution.
    Type: Grant
    Filed: June 6, 2002
    Date of Patent: November 23, 2004
    Assignee: Lambda Physik AG
    Inventors: Uwe Stamm, Hans-Stephan Albrecht, Günter Nowinski
  • Patent number: 6819698
    Abstract: A molecular fluorine (F2) laser system that includes a gaseous molecular fluorine gain medium contained in a laser tube, a resonant cavity, a power supply for exciting the gain medium to produce a laser beam having an ultra violet (UV) radiation output at substantially 157 nm and a red radiation output in the range of 620 to 760 nm, a discharge module connected to the laser tube for adding and withdrawing gas to the gain medium, a controller for controlling the power supply and the discharge module, and a photo diamond detector that receives a portion of the laser beam for measuring at least one optical parameter of the UV radiation such as energy, pulse energy, pulse shape, pulse width, etc. The photo diamond detector is substantially insensitive to the red radiation output that is also present in the laser beam.
    Type: Grant
    Filed: February 24, 2000
    Date of Patent: November 16, 2004
    Assignee: Lambda Physik AG
    Inventor: Klaus Vogler
  • Patent number: 6807205
    Abstract: A method for operating an excimer or molecular fluorine laser system at a stabilized wavelength includes generating a laser beam and directing a beam portion through a wavelength measurement system, calibrating the wavelength measurement system to an absolute reference, determining the wavelength of the laser beam including figuring in a drift compensation value of the wavelength, and tuning the wavelength to a target wavelength when the determined wavelength differs from the target wavelength.
    Type: Grant
    Filed: July 10, 2001
    Date of Patent: October 19, 2004
    Assignee: Lambda Physik AG
    Inventors: Hans-Stephan Albrecht, Uwe Stamm, Wolfgang Zschocke
  • Patent number: 6804327
    Abstract: The method and system herein pertain to an EUV photon source which includes a plasma chamber filled with a gas mixture, multiple electrodes within the plasma chamber defining a plasma region and a central axis, a power supply circuit connected to the electrodes for delivering a main pulse to the electrodes for energizing the plasma around the central axis to produce an EUV beam. The system can also include a preionizer for ionizing the gas mixture in preparing to form a dense plasma around the central axis upon application of the main pulse from the power supply circuit to the electrodes. A set of baffles may be disposed along the beam path outside of the pinch region to diffuse gaseous and contaminant particulate flow emanating from the pinch region and to absorb or reflect acoustic waves emanating from the pinch region away from the pinch region.
    Type: Grant
    Filed: March 27, 2002
    Date of Patent: October 12, 2004
    Assignee: Lambda Physik AG
    Inventors: Guido Schriever, Ulrich Rebhan
  • Patent number: 6801561
    Abstract: An excimer or molecular fluorine laser system a wavefront compensating optic within its resonator for adjusting the curvature of the wavefront of the beam for compensating wavefront distortions and thereby enhancing the spectral purity of the beam. The wavefront compensating optic may be a plate, such as a null lens. One or both surfaces of the null lens may be adjustable and/or have an adjustable curvature for controlling the wavefront distortion compensation. A multi-compartment enclosure may be included having at least one optical component of the line-narrowing unit within each compartment. An atmosphere within at least one compartment is preferably controlled for controlling the spectral purity of the beam by controlling an amount of wavefront distortion compensation. The wavefront compensating optic may be sealably disposed between adjacent compartments.
    Type: Grant
    Filed: September 21, 2001
    Date of Patent: October 5, 2004
    Assignee: Lambda Physik AG
    Inventor: Juergen Kleinschmidt
  • Patent number: 6795456
    Abstract: A failure analysis system and method for multi-layer semiconductor devices, including a molecular fluorine laser system for producing a 157 nm beam and an imaging system for imaging the beam onto the semiconductor device. The laser beam etches away one or more top (passivation) layers to expose layers disposed underneath. Circuitry formed in exposed layers can then be tested.
    Type: Grant
    Filed: December 8, 2000
    Date of Patent: September 21, 2004
    Assignee: Lambda Physik AG
    Inventor: Michael J. Scaggs
  • Patent number: 6795473
    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, and multiple electrodes with the laser chamber connected to a discharge circuit energizing the gas mixture. The laser chamber is within a laser resonator generating an output beam. The resonator includes a line-narrowing package for reducing a bandwidth of the output beam. The line-narrowing package includes a grating or grism element for use with a highly reflective (HR) and/or an anti-reflective (AR) dielectric coating. The grating may serve as a resonator reflector having a dielectric HR coating. The grating may be disposed before a HR mirror and thus have a dielectric AR or HR coating when the grating is configured in transmission or reflection mode, respectively. The grating may be used as an output coupler, and may be partially reflective with or without a coating.
    Type: Grant
    Filed: June 22, 2000
    Date of Patent: September 21, 2004
    Assignee: Lambda Physik AG
    Inventors: Juergen Kleinschmidt, Thomas Schroeder
  • 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: 6785316
    Abstract: A final stage capacitance of a pulse compression circuit for an excimer or molecular fluorine lithography laser system is provided by a set of peaking capacitors connected through a first inductance to the electrodes and a set of sustaining capacitors connected to the electrodes through a second inductance substantially greater than the first inductance. Current pulses through the discharge are temporally extended relative to current pulses of a system having its final stage capacitance provided only by a set of peaking capacitors connected to the electrodes via the first inductance. An amplified spontaneous emission (ASE) level in the laser pulses is reduced thereby enhancing their spectral purity.
    Type: Grant
    Filed: August 17, 2000
    Date of Patent: August 31, 2004
    Assignee: Lambda Physik AG
    Inventors: Igor Bragin, Vadim Berger, Uwe Stamm
  • Patent number: 6768765
    Abstract: An excimer or molecular fluorine laser system includes a discharge tube filled with a gas mixture, multiple electrodes within the discharge tube and connected to a discharge circuit for energizing the gas mixture, a resonator for generating a laser beam, and at least one window structure including a first window and a second window. The first window initially seals the discharge tube and transmits the beam. The second window is initially unexposed to the gas mixture. The window structure is configured such that the second window is movable into position for sealing the discharge tube and transmitting the beam when the first window becomes contaminated.
    Type: Grant
    Filed: June 4, 2002
    Date of Patent: July 27, 2004
    Assignee: Lambda Physik AG
    Inventors: Thomas Schroeder, Rustem Osmanow, Juergen Baumler
  • Patent number: 6763048
    Abstract: A molecular fluorine laser system includes a discharge tube filled with a gas mixture including molecular fluorine and at least one buffer gas and having a total pressure of less than substantially 2500 mbar, multiple electrodes within the discharge tube, a pulsed discharge circuit connected to the electrodes for energizing the gas mixture, a line-selection optic for selecting one of multiple closely-spaced lines around 157 nm emitted from the discharge tube, and a laser resonator including the line-selection optic and the discharge tube for generating a beam of laser pulses having a wavelength around 157 nm at a bandwidth of less than 0.6 pm.
    Type: Grant
    Filed: June 15, 2001
    Date of Patent: July 13, 2004
    Assignee: Lambda Physik AG
    Inventors: Sergei Govorkov, Klaus Vogler, Rainer Paetzel
  • Patent number: 6760358
    Abstract: An apparatus for adjusting an orientation of an optical component mounted within a laser resonator with suppressed hysteresis includes an electromechanical device, a drive element, and a mechano-optical device coupled to the mounted optical component. The drive element is configured to contact and apply a force to the mechano-optical device in such a way as to adjust the orientation of the mechano-optical device, and thereby that of the optical component, to a known orientation within the laser resonator. The optical component is mounted such that stresses applied by the mount to the optical component are homogeneous and substantially thermally-independent.
    Type: Grant
    Filed: May 7, 2002
    Date of Patent: July 6, 2004
    Assignee: Lambda Physik AG
    Inventors: Kay Zimmermann, Konstantin Aab, Matthias Kramer, Marcus Serwazi
  • Patent number: 6757315
    Abstract: A preionization device for a gas laser includes an internal preionization electrode having a dielectric housing around it such that the preionization device is of corona type. The internal electrode connects to advantageous electrical circuitry, preferably external to the discharge chamber via a conductive feedthrough. The circuitry reduces the voltage across the dielectric tube of the preionization unit to reduce over-flashing at tube ends and oscillations due to residual energies stored in the dielectric. A semi-transparent mesh electrode between the preionization unit and the discharge area prevents field distortions and discharge instabilities.
    Type: Grant
    Filed: October 19, 2000
    Date of Patent: June 29, 2004
    Assignee: Lambda Physik AG
    Inventors: Igor Bragin, Vadim Berger, Ivan Tassy-Julien, Uwe Stamm