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).

  • Publication number: 20110121306
    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: Application
    Filed: May 10, 2010
    Publication date: May 26, 2011
    Applicant: 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: 20110108843
    Abstract: Collections of laterally crystallized semiconductor islands for use in thin film transistors and systems and methods for making same are described. A display device includes a plurality of thin film transistors (TFTs) on a substrate, such that the TFTs are spaced apart from each other and each include a channel region that has a crystalline microstructure and a direction along which a channel current flows. The channel region of each of the TFTs contains a crystallographic grain that spans the length of that channel region along its channel direction. Each crystallographic grain in the channel region of each of the TFTs is physically disconnected from and crystallographically uncorrelated with each crystallographic grain in the channel region of each adjacent TFT.
    Type: Application
    Filed: September 22, 2008
    Publication date: May 12, 2011
    Applicant: THE TRUSTEES OF COLUMBIA UNIVERSITY IN THE CITY OF NEW YORK
    Inventors: James S. Im, Ui-Jin Chung
  • Publication number: 20110108108
    Abstract: A method of making a crystalline film includes providing a film comprising seed grains of a selected crystallographic surface orientation on a substrate; irradiating the film using a pulsed light source to provide pulsed melting of the film under conditions that provide a mixed liquid/solid phase and allowing the mixed solid/liquid phase to solidify under conditions that provide a textured polycrystalline layer having the selected surface orientation. One or more irradiation treatments may be used. The film is suitable for use in solar cells.
    Type: Application
    Filed: February 27, 2009
    Publication date: May 12, 2011
    Applicant: The Trustees of Columbia University in the City of
    Inventors: James S. Im, Paul C. Van Der Wilt, Ui-Jin Chung
  • Publication number: 20110101368
    Abstract: The disclosed subject matter generally relates a method of irradiating a large area thin film with a pulsed light source. In some embodiments, the disclosed subject matter particularly relates to utilizing flash lamp annealing in combination with patterning techniques for making thin film devices. The flash lamp annealing can trigger lateral growth crystallization or explosive crystallization in large area thin films. In some embodiments, capping layers or proximity masks can be used in conjunction with the flash lamp annealing.
    Type: Application
    Filed: February 27, 2009
    Publication date: May 5, 2011
    Inventor: James S. Im
  • Patent number: 7906414
    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 beamlets using patterning masks. 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.
    Type: Grant
    Filed: February 18, 2010
    Date of Patent: March 15, 2011
    Assignee: The Trustees of Columbia University in the City of New York
    Inventor: James S. Im
  • Patent number: 7902052
    Abstract: A process and system are provided for processing at least one section of each of a plurality of semiconductor film samples. In these process and system, the irradiation beam source is controlled to emit successive irradiation beam pulses at a predetermined repetition rate. Using such emitted beam pulses, at least one section of one of the semiconductor film samples is irradiated using a first sequential lateral solidification (“SLS”) technique and/or a first uniform small grained material (“UGS”) techniques to process the such section(s) of the first sample. Upon the completion of the processing of this section of the first sample, the beam pulses are redirected to impinge at least one section of a second sample of the semiconductor film samples. Then, using the redirected beam pulses, such section(s) of the second sample are irradiated using a second SLS technique and/or a second UGS technique to process the at least one section of the second sample.
    Type: Grant
    Filed: January 14, 2008
    Date of Patent: March 8, 2011
    Assignee: The Trustees of Columbia University in the City of New York
    Inventor: James S. Im
  • Publication number: 20100270557
    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: Application
    Filed: September 25, 2008
    Publication date: October 28, 2010
    Applicant: THE TRUSTEES OF COLUMBIA UNIVERSITY IN THE CITY OF NEW YORK
    Inventor: James S. Im
  • Publication number: 20100233888
    Abstract: An arrangement, process and mask for implementing single-scan continuous motion sequential lateral solidification of a thin film provided on a sample such that artifacts formed at the edges of the beamlets irradiating the thin film are significantly reduced. According to this invention, the edge areas of the previously irradiated and resolidified areas which likely have artifacts provided therein are overlapped by the subsequent beamlets. In this manner, the edge areas of the previously resolidified irradiated areas and artifacts therein are completely melted throughout their thickness. At least the subsequent beamlets are shaped such that the grains of the previously irradiated and resolidified areas which border the edge areas melted by the subsequent beamlets grow into these resolidifying edges areas so as to substantially reduce or eliminate the artifacts.
    Type: Application
    Filed: April 9, 2010
    Publication date: September 16, 2010
    Inventor: James S. Im
  • Publication number: 20100197147
    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 beamlets using patterning masks. 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.
    Type: Application
    Filed: February 18, 2010
    Publication date: August 5, 2010
    Inventor: JAMES S. IM
  • Patent number: 7759230
    Abstract: An arrangement, process and mask for implementing single-scan continuous motion sequential lateral solidification of a thin film provided on a sample such that artifacts formed at the edges of the beamlets irradiating the thin film are significantly reduced. According to this invention, the edge areas of the previously irradiated and resolidified areas which likely have artifacts provided therein are overlapped by the subsequent beamlets. In this manner, the edge areas of the previously resolidified irradiated areas and artifacts therein are completely melted throughout their thickness. At least the subsequent beamlets are shaped such that the grains of the previously irradiated and resolidified areas which border the edge areas melted by the subsequent beamlets grow into these resolidifying edges areas so as to substantially reduce or eliminate the artifacts.
    Type: Grant
    Filed: March 7, 2006
    Date of Patent: July 20, 2010
    Assignee: The Trustees of Columbia University in the City of New York
    Inventor: James S. Im
  • Patent number: 7718517
    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 beamlets using patterning masks. 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.
    Type: Grant
    Filed: August 19, 2003
    Date of Patent: May 18, 2010
    Inventor: James S. Im
  • Patent number: 7709378
    Abstract: A method and apparatus for processing a thin metal layer on a substrate to control the grain size, grain shape, and grain boundary location and orientation in the metal layer by irradiating the metal layer with a first excimer laser pulse having an intensity pattern defined by a mask to have shadow regions and beamlets. Each region of the metal layer overlapped by a beamlet is melted throughout its entire thickness, and each region of the metal layer overlapped by a shadow region remains at least partially unmelted. After completion of resolidification of the melted regions following irradiation by the first excimer laser pulse, the metal layer is irradiated by a second excimer laser pulse having a shifted intensity pattern so that the shadow regions overlap regions of the metal layer having fewer and larger grains.
    Type: Grant
    Filed: August 10, 2006
    Date of Patent: May 4, 2010
    Assignee: The Trustees of Columbia University in the City of New York
    Inventor: James S. Im
  • Patent number: 7704862
    Abstract: Systems and methods for reducing a surface roughness of a polycrystalline or single crystal thin film produced by the sequential lateral solidification process are disclosed.
    Type: Grant
    Filed: February 6, 2007
    Date of Patent: April 27, 2010
    Assignee: The Trustees of Columbia University
    Inventors: James S. Im, Robert S. Sposili, Mark A. Crowder
  • Publication number: 20100099273
    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: December 22, 2009
    Publication date: April 22, 2010
    Inventor: James S. Im
  • Patent number: 7691687
    Abstract: A crystalline film includes a first crystalline region having a first film thickness and a first crystalline grain structure; and a second crystalline region having a second film thickness and a second crystalline grain structure. The first film thickness is greater than the second film thickness and the first and second film thicknesses are selected to provide a crystalline region having the degree and orientation of crystallization that is desired for a device component.
    Type: Grant
    Filed: January 9, 2007
    Date of Patent: April 6, 2010
    Assignee: The Trustees of Columbia University in the City of New York
    Inventor: James S. Im
  • Publication number: 20100065853
    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: Application
    Filed: September 9, 2009
    Publication date: March 18, 2010
    Inventor: JAMES S. IM
  • Patent number: 7679028
    Abstract: Methods for processing an amorphous silicon thin film sample into a polycrystalline silicon thin film are disclosed.
    Type: Grant
    Filed: May 4, 2007
    Date of Patent: March 16, 2010
    Assignee: The Trustees of Columbia University in the City of New York
    Inventors: James S. Im, Robert S. Sposili, Mark A. Crowder
  • Publication number: 20100032586
    Abstract: Methods for processing an amorphous silicon thin film sample into a polycrystalline silicon thin film are disclosed.
    Type: Application
    Filed: September 25, 2009
    Publication date: February 11, 2010
    Inventors: James S. Im, Robert S. Sposili, Mark A. Crowder
  • Patent number: 7645337
    Abstract: In accordance with one aspect, the present invention provides a method for providing polycrystalline films having a controlled microstructure as well as a crystallographic texture. The methods provide elongated grains or single-crystal islands of a specified crystallographic orientation. In particular, a method of processing a film on a substrate includes generating a textured film having crystal grains oriented predominantly in one preferred crystallographic orientation; and then generating a microstructure using sequential lateral solidification crystallization that provides a location-controlled growth of the grains orientated in the preferred crystallographic orientation.
    Type: Grant
    Filed: November 18, 2004
    Date of Patent: January 12, 2010
    Assignee: The Trustees of Columbia University in the City of New York
    Inventors: James S. Im, Paul Christian van der Wilt
  • Patent number: 7638728
    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: March 10, 2006
    Date of Patent: December 29, 2009
    Assignee: The Trustees of Columbia University in the City of New York
    Inventor: James S. Im