Patents by Inventor James S. Im

James S. Im 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: 8440581
    Abstract: The disclosed systems and method for non-periodic pulse sequential lateral solidification relate to processing a thin film. The method for processing a thin film, while advancing a thin film in a selected direction, includes irradiating a first region of the thin film with a first laser pulse and a second laser pulse and irradiating a second region of the thin film with a third laser pulse and a fourth laser pulse, wherein the time interval between the first laser pulse and the second laser pulse is less than half the time interval between the first laser pulse and the third laser pulse. In some embodiments, each pulse provides a shaped beam and has a fluence that is sufficient to melt the thin film throughout its thickness to form molten zones that laterally crystallize upon cooling. In some embodiments, the first and second regions are adjacent to each other. In some embodiments, the first and second regions are spaced a distance apart.
    Type: Grant
    Filed: May 10, 2010
    Date of Patent: May 14, 2013
    Assignee: The Trustees of Columbia University in the City of New York
    Inventors: James S. Im, Ui-Jin Chung, Alexander B. Limanov, Paul C. Van Der Wilt
  • Publication number: 20130105807
    Abstract: In one aspect, the present disclosure relates to a method of processing a thin film including, while advancing a thin film in a first selected direction, irradiating a first region of the thin film with a first laser pulse and a second laser pulse, each laser pulse providing a shaped beam and having a fluence that is sufficient to partially melt the thin film and the first region re-solidifying and crystallizing to form a first crystallized region, and irradiating a second region of the thin film with a third laser pulse and a fourth laser pulse, each pulse providing a shaped beam and having a fluence that is sufficient to partially melt the thin film and the second region re-solidifying and crystallizing to form a second crystallized region, wherein the time interval between the first laser pulse and the second laser pulse is less than half the time interval between the first laser pulse and the third laser pulse.
    Type: Application
    Filed: November 2, 2010
    Publication date: May 2, 2013
    Applicant: The Trustees of Columbia University in the city of New York
    Inventors: James S. Im, Yikang Deng, Qiongying Hu, Ui-Jin Chung, Alexander B. Limanov
  • Patent number: 8426296
    Abstract: The disclosed subject matter relates to systems and methods for preparing epitaxially textured polycrystalline films. In one or more embodiments, the method for making a textured thin film includes providing a precursor film on a substrate, the film includes crystal grains having a surface texture and a non-uniform degree of texture throughout the thickness of the film, wherein at least a portion of the this substrate is transparent to laser irradiation; and irradiating the textured precursor film through the substrate using a pulsed laser crystallization technique at least partially melt the film wherein the irradiated film crystallizes upon cooling to form crystal grains having a uniform degree of texture.
    Type: Grant
    Filed: August 29, 2011
    Date of Patent: April 23, 2013
    Assignee: The Trustees of Columbia University in the City of New York
    Inventor: James S. Im
  • Patent number: 8415670
    Abstract: Methods of producing high uniformity in thin film transistor devices fabricated on laterally crystallized thin films are described. A thin film transistor (TFT) includes a channel area disposed in a crystalline substrate, which has grain boundaries that are approximately parallel with each other and are spaced apart with approximately equal spacings. The shape of the channel area includes a non-equiangular polygon that has two opposing side edges that are oriented substantially perpendicular to the grain boundaries. The polygon further has an upper edge and a lower edge. At least a portion of each of the upper and lower edges is oriented at a tilt angle with respect to the grain boundaries. The tilt angles are selected such that the number of grain boundaries covered by the polygon is independent of the location of the channel area within the crystalline substrate.
    Type: Grant
    Filed: September 25, 2008
    Date of Patent: April 9, 2013
    Assignee: The Trustees of Columbia University in the City of New York
    Inventor: James S. Im
  • Patent number: 8411713
    Abstract: A process and system for processing a thin film sample are provided. In particular, a beam generator can be controlled to emit at least one beam pulse. The beam pulse is then masked to produce at least one masked beam pulse, which is used to irradiate at least one portion of the thin film sample. With the at least one masked beam pulse, the portion of the film sample is irradiated with sufficient intensity for such portion to later crystallize. This portion of the film sample is allowed to crystallize so as to be composed of a first area and a second area. Upon the crystallization thereof, the first area includes a first set of grains, and the second area includes a second set of grains whose at least one characteristic is different from at least one characteristic of the second set of grains. The first area surrounds the second area, and is configured to allow an active region of a thin-film transistor (“TFT”) to be provided at a distance therefrom.
    Type: Grant
    Filed: September 9, 2009
    Date of Patent: April 2, 2013
    Assignee: The Trustees of Columbia University in the city of New York
    Inventor: James S. Im
  • Publication number: 20130071974
    Abstract: High throughput systems and processes for recrystallizing thin film semiconductors that have been deposited at low temperatures on a substrate are provided. A thin film semiconductor workpiece is irradiated with a laser beam to melt and recrystallize target areas of the surface exposed to the laser beam. The laser beam is shaped into one or more pulses. The beam pulses have suitable dimensions and orientations to pattern the laser beam radiation so that the areas targeted by the beam have dimensions and orientations that are conductive to semiconductor recrystallization. The workpiece is mechanically translated along linear paths relative to the laser beam to process the entire surface of the workpiece at high speeds. Position sensitive triggering of a laser can be used to generate laser beam pulses to melt and recrystallize semiconductor material at precise locations on the surface of the workpiece while it is translated on a motorized stage.
    Type: Application
    Filed: August 23, 2012
    Publication date: March 21, 2013
    Applicant: Columbia University
    Inventor: James S. Im
  • Publication number: 20130012036
    Abstract: A system for preparing a semiconductor film, the system including: a laser source; optics to form a line beam, a stage to support a sample capable of translation; memory for storing a set of instructions, the instructions including irradiating a first region of the film with a first laser pulse to form a first molten zone, said first molten zone having a maximum width (Wmax) and a minimum width (Wmin), wherein the first molten zone crystallizes to form laterally grown crystals; laterally moving the film in the direction of lateral growth a distance greater than about one-half Wmax less than Wmin; and irradiating a second region of the film with a second laser pulse to form a second molten zone, wherein the second molten zone crystallizes to form laterally grown crystals that are elongations of the crystals in the first region, wherein laser optics provide less than 2×Wmin.
    Type: Application
    Filed: July 12, 2012
    Publication date: January 10, 2013
    Applicant: COLUMBIA UNIVERSITY
    Inventors: James S. IM, Paul C. VAN DER WILT
  • Publication number: 20130009074
    Abstract: Methods for processing an amorphous silicon thin film sample into a polycrystalline silicon thin film are disclosed. One method includes generating a sequence of excimer laser pulses, controllably modulating each pulse to a predetermined fluence, homoginizing each modulated pulse in a predetermined plane, masking portions of each homoginized pulse with a pattern of slits to generate a sequence of fluence controlled pulses of line patterned beamlets, each slit in the pattern of slits being sufficiently narrow to prevent inducement of significant nucleation in region of a silicon thin film sample irradiated by a beamlet corresponding to the slit, irradiating an amorphous silicon thin film sample with the sequence of fluence controlled slit patterned beamlets to effect melting of portions corresponding to each fluence controlled patterned beamlet pulse, and controllably sequentially translating a relative position of the sample with respect to each of the fluence controlled pulse of slit patterned beamlets.
    Type: Application
    Filed: August 28, 2012
    Publication date: January 10, 2013
    Inventors: James S. Im, Robert S. Sposili, Mark A. Crowder
  • Patent number: 8278659
    Abstract: Methods for processing an amorphous silicon thin film sample into a polycrystalline silicon thin film are disclosed.
    Type: Grant
    Filed: September 25, 2009
    Date of Patent: October 2, 2012
    Assignee: The Trustees of Columbia University in the city of New York
    Inventors: James S. Im, Robert S. Sposili, Mark A. Crowder
  • Patent number: 8221544
    Abstract: A polycrystalline film is prepared by (a) providing a substrate having a thin film disposed thereon, said film capable of laser-induced melting, (b) generating a sequence of laser pulses having a fluence that is sufficient to melt the film throughout its thickness in an irradiated region, each pulse forming a line beam having a predetermined length and width, said width sufficient to prevent nucleation of solids in a portion of the thin film that is irradiated by the laser pulse, (c) irradiating a first region of the film with a first laser pulse to form a first molten zone, said first molten zone demonstrating a variation in width along its length to thereby define a maximum width (Wmax) and a minimum width (Wmin), wherein the first molten zone crystallizes upon cooling to form one or more laterally grown crystals, (d) laterally moving the film in the direction of lateral growth a distance that is greater than about one-half Wmax and less than Wmin; and (e) irradiating a second region of the film with a seco
    Type: Grant
    Filed: December 2, 2005
    Date of Patent: July 17, 2012
    Assignee: The Trustees of Columbia University in the City of New York
    Inventors: James S. Im, Paul C. Van Der Wilt
  • Publication number: 20120045191
    Abstract: The disclosed subject matter relates to systems and methods for preparing epitaxially textured polycrystalline films. In one or more embodiments, the method for making a textured thin film includes providing a precursor film on a substrate, the film includes crystal grains having a surface texture and a non-uniform degree of texture throughout the thickness of the film, wherein at least a portion of the this substrate is transparent to laser irradiation; and irradiating the textured precursor film through the substrate using a pulsed laser crystallization technique at least partially melt the film wherein the irradiated film crystallizes upon cooling to form crystal grains having a uniform degree of texture.
    Type: Application
    Filed: August 29, 2011
    Publication date: February 23, 2012
    Applicant: Columbia University
    Inventor: James S. IM
  • Publication number: 20120034794
    Abstract: A system, method and masking arrangement are provided of enhancing the width of polycrystalline grains produced using sequential lateral solidification using a modified mask pattern is disclosed. One exemplary mask pattern employs rows of diamond or circular shaped areas in order to control the width of the grain perpendicular to the direction of primary crystallization.
    Type: Application
    Filed: October 14, 2011
    Publication date: February 9, 2012
    Applicant: THE TRUSTEES OF COLUMIBA UNIVERSITY IN THE CITY OF NEW YORK
    Inventor: James S. Im
  • Publication number: 20110309370
    Abstract: Crystallization of thin films using pulsed irradiation The method includes continuously irradiating a film having an x-axis and a y-axis, in a first scan in the x-direction of the film with a plurality of line beam laser pulses to form a first set of irradiated regions, translating the film a distance in the y-direction of the film, wherein the distance is less than the length of the line beam, and continuously irradiating the film in a second scan in the negative x-direction of the film with a sequence of line beam laser pulses to form a second set of irradiated regions, wherein each of the second set of irradiated regions overlaps with a portion of the first set of irradiated regions, and wherein each of the first and the second set of irradiated regions upon cooling forms one or more crystallized regions.
    Type: Application
    Filed: November 13, 2009
    Publication date: December 22, 2011
    Applicant: THE TRUSTEES OF COLUMBIA UNIVERSITY IN THE CITY OF NEW YORK
    Inventor: James S. IM
  • Patent number: 8063338
    Abstract: A system, method and masking arrangement are provided of enhancing the width of polycrystalline grains produced using sequential lateral solidification using a modified mask pattern is disclosed. One exemplary mask pattern employs rows of diamond or circular shaped areas in order to control the width of the grain perpendicular to the direction of primary crystallization.
    Type: Grant
    Filed: December 22, 2009
    Date of Patent: November 22, 2011
    Assignee: The Trustees of Columbia in the City of New York
    Inventor: James S. Im
  • Publication number: 20110248278
    Abstract: A method of processing a polycrystalline film on a substrate includes generating laser pulses, directing the laser pulses through a mask to generate patterned laser beams, each having a length l?, a width w?, and a spacing between adjacent beams d?; irradiating a region of the film with the patterned beams, said beams having an intensity sufficient to melt and to induce crystallization of the irradiated portion of the film, wherein the film region is irradiated n times; and after irradiation of each film portion, translating the film and/or the mask, in the x- and y-directions. The distance of translation in the y-direction is about l?/n??, where ? is a value selected to overlap the beamlets from one irradiation step to the next. The distance of translation in the x-direction is selected such that the film is moved a distance of about ?? after n irradiations, where ??=w?+d?.
    Type: Application
    Filed: June 21, 2011
    Publication date: October 13, 2011
    Inventors: James S. IM, Paul Christiaan VAN DER WILT
  • Patent number: 8034698
    Abstract: The present invention is directed to systems and methods for irradiating regions of a thin film sample(s) with laser beam pulses having different energy beam characteristics that are generated and delivered via different optical paths. An exemplary method includes generating laser beam pulses having energy beam characteristics, directing a first pulse onto a first optical path, modulating the pulse's energy beam characteristics, and irradiating at least a portion of a first region of the thin film with the pulse to induce crystallization of the portion of the first region. The method also includes directing a second pulse onto a second optical path, modulating the pulse's energy beam characteristics so as to be different from the energy beam characteristics of the first pulse, and irradiating at least a portion of a second region of the thin film with the second pulse to induce crystallization of the portion of the second region.
    Type: Grant
    Filed: October 16, 2007
    Date of Patent: October 11, 2011
    Assignee: The Trustees of Columbia University in the City of New York
    Inventor: James S. Im
  • Patent number: 8012861
    Abstract: The disclosed subject matter relates to systems and methods for preparing epitaxially textured polycrystalline films. In one or more embodiments, the method for making a textured thin film includes providing a precursor film on a substrate, the film includes crystal grains having a surface texture and a non-uniform degree of texture throughout the thickness of the film, wherein at least a portion of the this substrate is transparent to laser irradiation; and irradiating the textured precursor film through the substrate using a pulsed laser crystallization technique at least partially melt the film wherein the irradiated film crystallizes upon cooling to form crystal grains having a uniform degree of texture.
    Type: Grant
    Filed: November 21, 2008
    Date of Patent: September 6, 2011
    Assignee: The Trustees of Columbia University in the City of New York
    Inventor: James S. Im
  • Publication number: 20110186854
    Abstract: High throughput systems and processes for recrystallizing thin film semiconductors that have been deposited at low temperatures on a substrate are provided. A thin film semiconductor workpiece (170) is irradiated with a laser beam (164) to melt and recrystallize target areas of the surface exposed to the laser beam. The laser beam is shaped into one or more beamlets using patterning masks (150). The mask patterns have suitable dimensions and orientations to pattern the laser beam radiation so that the areas targeted by the beamlets have dimensions and orientations that are conducive to semiconductor recrystallization. The workpiece is mechanically translated along linear paths relative to the laser beam to process the entire surface of the work piece at high speeds. Position sensitive triggering of a laser can be used generate laser beam pulses to melt and recrystallize semiconductor material at precise locations on the surface of the workpiece while it is translated on a motorized stage (180).
    Type: Application
    Filed: February 1, 2011
    Publication date: August 4, 2011
    Inventor: James S. Im
  • Publication number: 20110175099
    Abstract: Methods and devices are described relating to an electronic device positioned at a known location in a crystalline film including a crystalline semiconductor comprising a region of location controlled crystalline grains; a device located in the crystalline semiconductor film at a location that is defined relative to the location of the location controlled crystalline grains. The method includes irradiating at least a portion of a semiconductor film using two or more overlapping irradiation steps, wherein each irradiation step at least partially melts and laterally crystallizes a lithographically defined region the film to obtain a region of laterally grown crystalline grains having at least one long grain boundary that is perpendicular to the lateral growth length; identifying the location of at least one long grain boundary; and manufacturing an electronic device in the semiconductor film at a location that is defined relative to the location of the long grain boundary.
    Type: Application
    Filed: March 2, 2009
    Publication date: July 21, 2011
    Applicant: The Trustees of Columbia University in the City of New York
    Inventor: James S. Im
  • Patent number: 7964480
    Abstract: A method of processing a polycrystalline film on a substrate includes generating laser pulses, directing the laser pulses through a mask to generate patterned laser beams, each having a length l?, a width w?, and a spacing between adjacent beams d?; irradiating a region of the film with the patterned beams, said beams having an intensity sufficient to melt and to induce crystallization of the irradiated portion of the film, wherein the film region is irradiated n times; and after irradiation of each film portion, translating the film and/or the mask, in the x- and y-directions. The distance of translation in the y-direction is about l?/n-?, where ? is a value selected to overlap the beamlets from one irradiation step to the next. The distance of translation in the x-direction is selected such that the film is moved a distance of about ?? after n irradiations, where ??=w?+d?.
    Type: Grant
    Filed: October 23, 2007
    Date of Patent: June 21, 2011
    Assignee: Trustees of Columbia University in the City of New York
    Inventors: James S. Im, Paul C. Van Der Wilt