Patents by Inventor Palash P. Das
Palash P. Das 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).
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Patent number: 8737438Abstract: A laser crystallization apparatus and method are disclosed for selectively melting a film such as amorphous silicon that is deposited on a substrate. The apparatus may comprise an optical system for producing stretched laser pulses for use in melting the film. In still another aspect of an embodiment of the present invention, a system and method are provided for stretching a laser pulse. In another aspect, a system is provided for maintaining a divergence of a pulsed laser beam (stretched or non-stretched) at a location along a beam path within a predetermined range. In another aspect, a system may be provided for maintaining the energy density at a film within a predetermined range during an interaction of the film with a shaped line beam.Type: GrantFiled: August 9, 2012Date of Patent: May 27, 2014Assignee: Cymer, LLCInventors: Palash P. Das, Thomas Hofmann, Jesse D. Davis, Richard L. Sandstrom
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Patent number: 8362391Abstract: A high energy, high repetition rate workpiece surface heating apparatus is disclosed which comprise a XeF laser producing a laser output light pulse beam, an optical system narrowing the laser output light pulse beam in the short axis of the laser output light pulse beam and expanding the laser output light pulse beam to form in a long axis of the beam a workpiece covering extent of the long axis, the optical system focuses the laser output light pulse beam at a field stop with a magnification sufficient to maintain an intensity profile that has sufficiently steep sidewalls to allow the field stop to maintain a sufficiently steep beam profile at the workpiece.Type: GrantFiled: December 27, 2010Date of Patent: January 29, 2013Assignee: TCZ, LLCInventors: William N. Partlo, Palash P. Das, Russell Hudyma, Michael Thomas
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Publication number: 20120298838Abstract: A laser crystallization apparatus and method are disclosed for selectively melting a film such as amorphous silicon that is deposited on a substrate. The apparatus may comprise an optical system for producing stretched laser pulses for use in melting the film. In still another aspect of an embodiment of the present invention, a system and method are provided for stretching a laser pulse. In another aspect, a system is provided for maintaining a divergence of a pulsed laser beam (stretched or non-stretched) at a location along a beam path within a predetermined range. In another aspect, a system may be provided for maintaining the energy density at a film within a predetermined range during an interaction of the film with a shaped line beam.Type: ApplicationFiled: August 9, 2012Publication date: November 29, 2012Applicant: CYMER, INC.Inventors: Palash P. Das, Thomas Hofmann, Jesse D. Davis, Richard L. Sandstrom
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Patent number: 8265109Abstract: A laser crystallization apparatus and method are disclosed for selectively melting a film such as amorphous silicon that is deposited on a substrate. The apparatus may comprise an optical system for producing stretched laser pulses for use in melting the film. In still another aspect of an embodiment of the present invention, a system and method are provided for stretching a laser pulse. In another aspect, a system is provided for maintaining a divergence of a pulsed laser beam (stretched or non-stretched) at a location along a beam path within a predetermined range. In another aspect, a system may be provided for maintaining the energy density at a film within a predetermined range during an interaction of the film with a shaped line beam.Type: GrantFiled: April 21, 2009Date of Patent: September 11, 2012Assignee: Cymer, Inc.Inventors: Palash P. Das, Thomas Hofmann, Jesse D. Davis, Richard L. Sandstrom
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Publication number: 20110163077Abstract: A high energy, high repetition rate workpiece surface heating apparatus is disclosed which comprise a XeF laser producing a laser output light pulse beam, an optical system narrowing the laser output light pulse beam in the short axis of the laser output light pulse beam and expanding the laser output light pulse beam to form in a long axis of the beam a workpiece covering extent of the long axis, the optical system focuses the laser output light pulse beam at a field stop with a magnification sufficient to maintain an intensity profile that has sufficiently steep sidewalls to allow the field stop to maintain a sufficiently steep beam profile at the workpiece.Type: ApplicationFiled: December 27, 2010Publication date: July 7, 2011Applicant: TCZ LLCInventors: William N. Partlo, Palash P. Das, Russell Hudyma, Michael Thomas
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Patent number: 7884303Abstract: A high, energy, high repetition rate workpiece surface heating apparatus is disclosed which comprise a XeF laser producing a laser output light pulse beam, an optical system narrowing the laser output light pulse beam in the short axis of the laser output light pulse beam and expanding the laser output light pulse beam to form in a long axis of the beam a workpiece covering extent of the long axis, the optical system focuses the laser output light pulse beam at a field stop with a magnification sufficient to maintain an intensity profile that has sufficiently steep sidewalls to allow the field stop to maintain a sufficiently steep beam profile at the workpiece.Type: GrantFiled: August 11, 2005Date of Patent: February 8, 2011Assignee: TCZ LLCInventors: William N. Partlo, Palash P. Das, Russell Hudyma, Michael Thomas
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Publication number: 20090256057Abstract: A laser crystallization apparatus and method are disclosed for selectively melting a film such as amorphous silicon that is deposited on a substrate. The apparatus may comprise an optical system for producing stretched laser pulses for use in melting the film. In still another aspect of an embodiment of the present invention, a system and method are provided for stretching a laser pulse. In another aspect, a system is provided for maintaining a divergence of a pulsed laser beam (stretched or non-stretched) at a location along a beam path within a predetermined range. In another aspect, a system may be provided for maintaining the energy density at a film within a predetermined range during an interaction of the film with a shaped line beam.Type: ApplicationFiled: April 21, 2009Publication date: October 15, 2009Applicant: Cymer, Inc.Inventors: Palash P. Das, Thomas Hofmann, Jesse D. Davis, Richard L. Sandstrom
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Patent number: 7567607Abstract: An oscillator-amplifier gas discharge laser system and method is disclosed which may comprise a first laser unit which may comprise a first discharge region which may contain an excimer or molecular fluorine lasing gas medium; a first pair of electrodes defining the first discharge region containing the lasing gas medium, a line narrowing unit for narrowing a spectral bandwidth of output laser light pulse beam pulses produced in said first discharge region; a second laser unit which may comprise a second discharge chamber which may contain an excimer or molecular fluorine lasing gas medium; a second pair of electrodes defining the second discharge region containing the lasing gas medium; a pulse power system providing electrical pulses to the first pair of electrodes and to the second pair of electrodes producing gas discharges in the lasing gas medium between the respective first and second pair of electrodes, and laser parameter control mechanism modifying a selected parameter of a selected laser output ligType: GrantFiled: February 1, 2006Date of Patent: July 28, 2009Assignee: Cymer, Inc.Inventors: David S. Knowles, Daniel J. W. Brown, Herve A. Besaucele, David W. Myers, Alexander I. Ershov, William N. Partlo, Richard L. Sandstrom, Palash P. Das, Stuart L. Anderson, Igor V. Fomenkov, Richard C. Ujazdowski, Eckehard D. Onkels, Richard M. Ness, Scot T. Smith, William G. Hulburd, Jeffrey Oicles
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Patent number: 7471455Abstract: Systems and methods are disclosed for shaping a laser beam for interaction with a film in which the laser beam travels along a beam path and defines a short-axis and a long-axis. In one aspect, the system may include a first short-axis element having an edge positioned at a distance, d1, along the beam path from the film and a second short-axis element having an edge positioned at a distance, d2, along the beam path from the film, with d2<d1. An optic may be positioned along the beam path between the second element and the film for focusing the beam in the short-axis for interaction with the film. In another aspect, a system may be provided having a mechanism operative to selectively adjust the curvature of one or both of the edges of the short-axis element.Type: GrantFiled: October 28, 2005Date of Patent: December 30, 2008Assignee: Cymer, Inc.Inventors: Palash P. Das, Albert P. Cefalo, David S. Knowles, Vitaliy Shklover, Holger Muenz
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Patent number: 7415056Abstract: A gas discharge laser system producing a laser output pulse and a method of operating such a system is disclosed which may comprise a pulse stretcher which may comprise a laser output pulse optical delay initiating optic directing a portion of the laser output pulse along a laser system output pulse optical axis and diverting a portion of the output pulse into an optical delay having an optical delay path and which may comprise a plurality of confocal resonators in series aligned to deliver an output of the optical delay to the laser output pulse optical delay initiating optic; an optical axis alignment mechanism comprising an radial mirror positioning mechanism operable to position the output of the optical delay to the align with the portion of the laser output pulse transmitted along the optical axis of the portion of the laser system output pulse transmitted by the laser output pulse optical delay initiating optic.Type: GrantFiled: March 31, 2006Date of Patent: August 19, 2008Assignee: Cymer, Inc.Inventors: Palash P. Das, Thomas Hofmann, Gang Lei
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Patent number: 7277188Abstract: Systems and methods are disclosed for focusing a beam for an interaction with a film deposited on a substrate wherein the focused beam defines a short axis and a long axis. In one aspect, the system may include a detecting system to analyze light reflected from the film on an image plane to determine whether the beam is focused in the short axis at the film. In still another aspect, a system may be provided for positioning a film (having an imperfect, non-planar surface) for interaction with a shaped line beam.Type: GrantFiled: May 26, 2005Date of Patent: October 2, 2007Assignees: Cymer, Inc., Carl Zeiss Industrielle Messtechnik GmbHInventors: Palash P. Das, Thomas Hofmann, Otto Boucky, Ernst Stump, Berthold Matzkovits, Michael Hoell, Joerg Walther, Kurt Brenner, Guenter Grupp
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Patent number: 7190707Abstract: A beam delivery unit and method of delivering a laser beam from a laser light source for excimer or molecular fluorine gas discharge laser systems in the DUV and smaller wavelengths is disclosed, which may comprise: a beam delivery enclosure defining an output laser light pulse beam delivery pat from an output of a gas discharge laser to an input of a working apparatus employing the light contained in the output laser light pulse beam; a purge mechanism operatively connected to the beam delivery enclosure; an in-situ beam parameter monitor and adjustment mechanism within the enclosure, comprising a retractable bean redirecting optic; a beam analysis mechanism external to the enclosure; and, a retraction mechanism within the enclosure and operable from outside the enclosure and operative to move the retractable beam redirecting optic from a retracted position out of the beam path to an operative position in the beam path.Type: GrantFiled: December 17, 2003Date of Patent: March 13, 2007Assignee: Cymer, Inc.Inventors: Palash P. Das, Khurshid Ahmed, Gregory Francis, Holger Glatzel, Alexei Lukashev, Jeremy Tyler, R. Kyle Webb
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Patent number: 7167499Abstract: A gas discharge laser crystallization apparatus and method for performing a transformation of a crystal makeup or orientation in the substrate of a workpiece is disclosed which may comprise, a multichamber laser system comprising, a first laser unit comprising, a first and second gas discharge chamber; each with a pair of elongated spaced apart opposing electrodes contained within the chamber, forming an elongated gas discharge region; a laser gas contained within the chamber comprising a halogen and a noble gas selected to produce laser light at a center wavelength optimized to the crystallization process to be earned out on the workpiece; a power supply module comprising, a DC power source; a first and a second pulse compression and voltage step up circuit connected to the DC power source and connected to the respective electrodes, comprising a multistage fractional step up transformer having a plurality of primary windings connected in series and a single secondary winding passing through each of the pluraType: GrantFiled: February 18, 2004Date of Patent: January 23, 2007Assignee: TCZ PTE. Ltd.Inventors: Palash P. Das, Bruce E. Bolliger, Partiv S. Patel, Brian C. Klene, Paul C. Melcher, Robert B. Saethre
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Patent number: 7149234Abstract: A high repetition rate, compact, modular gas discharge, ultraviolet laser. The laser is useful as a light source for very rapid inspections of wafers in an integrated circuit fabrication process. It is also useful for reticle writing at very rapid rates. A preferred embodiment operates at pulse repetition rates of 1000 to 4000 Hz and is designed for round-the-clock production line operation. This preferred embodiment comprises a pulse control unit which controls the timing of pulses to an accuracy of less than 4 nanoseconds. Preferred embodiments of this gas discharge laser can be configured to operate with a KrF gas mixture, an ArF gas mixture or an F2 gas mixture, each with an approximate buffer gas, producing 248 nm, 197 nm or 157 nm ultraviolet light pulses.Type: GrantFiled: August 27, 2003Date of Patent: December 12, 2006Assignee: Cymer, Inc.Inventors: Palash P. Das, Jennan Yu, Stuart L. Anderson, Helmut Schillinger, Tobias Pflanz, Claus Strowitzki, Claudia A. Hartmann, Stephan Geiger, Brett D. Smith, William N. Partlo
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Patent number: 7139301Abstract: An integrated circuit lithography technique called spectral engineering by Applicants, for bandwidth control of an electric discharge laser. In a preferred process, a computer model is used to model lithographic parameters to determine a desired laser spectrum needed to produce a desired lithographic result. A fast responding tuning mechanism is then used to adjust center wavelength of laser pulses in a burst of pulses to achieve an integrated spectrum for the burst of pulses approximating the desired laser spectrum. The laser beam bandwidth is controlled to produce an effective beam spectrum having at least two spectral peaks in order to produce improved pattern resolution in photo resist film. Line narrowing equipment is provided having at least one piezoelectric drive and a fast bandwidth detection control system having a time response of less than about 2.0 millisecond.Type: GrantFiled: November 3, 2003Date of Patent: November 21, 2006Assignee: CYMER, Inc.Inventors: Armen Kroyan, Ivan Lalovic, Igor V. Fomenkov, Palash P. Das, Richard L. Sandstrom, John M. Algots, Khurshid Ahmed
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Patent number: 7079556Abstract: A technique for bandwidth control of an electric discharge laser. Line narrowing equipment is provided having at least one piezoelectric drive and a fast bandwidth detection means and a bandwidth control having a time response of less than about 1.0 millisecond. In a preferred embodiment wavelength tuning mirror is dithered at dither rates of more than 500 dithers per second within a very narrow range of pivot angles to cause a dither in nominal wavelength values to produce a desired effective bandwidth of series of laser pulses.Type: GrantFiled: September 24, 2003Date of Patent: July 18, 2006Assignee: Cymer, Inc.Inventors: Igor V. Fomenkov, Armen Kroyan, Jesse D. Buck, Palash P. Das, Richard L. Sandstrom, Frederick G. Erie, John Martin Algots, Gamaralalage G. Padmabandu
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Patent number: 7061961Abstract: An oscillator-amplifier gas discharge laser system and method is disclosed which may comprise a first laser unit which may comprise a first discharge region which may contain an excimer or molecular fluorine lasing gas medium; a first pair of electrodes defining the first discharge region containing the lasing gas medium, a line narrowing unit for narrowing a spectral bandwidth of output laser light pulse beam pulses produced in said first discharge region; a second laser unit which may comprise a second discharge chamber which may contain an excimer or molecular fluorine lasing gas medium; a second pair of electrodes defining the second discharge region containing the lasing gas medium; a pulse power system providing electrical pulses to the first pair of electrodes and to the second pair of electrodes producing gas discharges in the lasing gas medium between the respective first and second pair of electrodes, and laser parameter control mechanism modifying a selected parameter of a selected laser output ligType: GrantFiled: August 9, 2005Date of Patent: June 13, 2006Assignee: Cymer, Inc.Inventors: David S. Knowles, Daniel J. W. Brown, Herve A. Besaucele, David W. Myers, Alexander I. Ershov, William N. Partlo, Richard L. Sandstrom, Palash P. Das, Stuart L. Anderson, Igor V. Fomenkov, Richard C. Ujazdowski, Eckehard D. Onkels, Richard M. Ness, Scot T. Smith, William G. Hulburd, Jeffrey Oicles
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Patent number: 7061959Abstract: A gas discharge laser crystallization apparatus and method for performing a transformation of a crystal makeup or orientation in a film on a workpiece is disclosed, which may comprise a master oscillator power amplifier MOPA or power oscillator power amplifier configured XeF laser system producing a laser output light pulse beam at a high repetition rate and high power with a pulse to pulse dose control; an optical system producing an elongated thin pulsed working beam from the laser output light pulse beam. The apparatus may further comprise the laser system is configured as a POPA laser system and further comprising: relay optics operative to direct a first output laser light pulse beam from a first laser PO unit into a second laser PA unit; and, a timing and control module timing the creation of a gas discharge in the first and second laser units within plus or minus 3 ns, to produce the a second laser output light pulse beam as an amplification of the first laser output light pulse beam.Type: GrantFiled: July 1, 2004Date of Patent: June 13, 2006Assignee: TCZ GmbHInventors: William N. Partlo, Palash P. Das, Russell Hudyma, Michael Thomas
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Patent number: 7016388Abstract: The present invention provides a modular high repetition rate ultraviolet gas discharge laser light source for a production line machine. The system includes an enclosed and purged beam path for delivery the laser beam to a desired location such as the entrance port of the production line machine. In preferred embodiments, the production line machine is a lithography machine and two separate discharge chambers are provided, one of which is a part of a master oscillator producing a very narrow band seed beam which is amplified in the second discharge chamber. This MOPA system is capable of output pulse energies approximately double the comparable single chamber laser system with greatly improved beam quality. A pulse stretcher more than doubles the output pulse length resulting in a reduction in pulse power (mJ/ns) as compared to prior art laser systems.Type: GrantFiled: November 12, 2003Date of Patent: March 21, 2006Assignee: Cymer, Inc.Inventors: Brian Klene, Palash P. Das, Steve Grove, Alexander Ershov, Scot Smith, Xiaojiang Pan, Richard L. Sandstrom
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Patent number: 7009140Abstract: A high energy, high repetition rate workpiece surface heating method and apparatus are disclosed which may cmprise a pulsed XeF laser operating at or above 4000 Hz and producing a laser output light pulse beam at a center wavelength of about 351 nm; an optical system narrowing the laser output light pulse beam to less than 20 ?m in a short axis of the laser output light pulse beam and expanding the laser output light pulse beam to form in a long axis of the beam a workpiece covering extent of teh long axis; the optical system including a field stop intermediate the laser and the workpiece; the workpiece comprising a layer to be heated; wherein the optical system focuses the laser output light pulse beam at a field stop with a magnification sufficient to maintain an intensity profile that has sufficiently steep sidewalls to allow the field stop to maintain a sufficiently steep beam profile at the workpiece without blocking the beam profile at too high an intensity level. 2.Type: GrantFiled: July 1, 2004Date of Patent: March 7, 2006Assignee: Cymer, Inc.Inventors: William N. Partio, Palash P. Das, Russell Hudyma, Michael Thomas