Patents by Inventor Ho Wai Lo

Ho Wai Lo 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: 7633034
    Abstract: Methods and systems use laser pulses to process a selected structure on or within a semiconductor substrate. The structure has a surface, a width, and a length. The laser pulses propagate along axes that move along a scan beam path relative to the substrate as the laser pulses process the selected structure. The method simultaneously generates on the selected structure first and second laser beam pulses that propagate along respective first and second laser beam axes intersecting the selected structure at distinct first and second locations. The first and second laser beam pulses impinge on the surface of the selected structure respective first and second beam spots. Each beam spot encompasses at least the width of the selected link. The first and second beam spots are spatially offset from one another along the length of the selected structure to define an overlapping region covered by both the first and the second beam spots and a total region covered by one or both of the first and second beam spots.
    Type: Grant
    Filed: February 4, 2005
    Date of Patent: December 15, 2009
    Assignee: Electro Scientific Industries, Inc.
    Inventors: Kelly J. Bruland, Brian W. Baird, Ho Wai Lo, Richard S. Harris, Yunlong Sun
  • Publication number: 20090011614
    Abstract: Methods and systems selectively irradiate structures on or within a semiconductor wafer using multiple laser beams. The structures may be laser-severable conductive links, and the purpose of the irradiation may be to sever selected links. The structures are arranged in rows and may be processed in either an on-axis mode or a cross-axis mode. In the on-axis mode, the beam spots fall on structures in the same row as they move along the row. In the cross-axis mode, the beam spots fall on structures in different rows as they move along the rows.
    Type: Application
    Filed: September 15, 2008
    Publication date: January 8, 2009
    Applicant: Electro Scientific Industries, Inc.
    Inventors: Kelly J. Bruland, Brian W. Baird, Ho Wai Lo, Stephen N. Swaringen, Frank G. Evans
  • Patent number: 7435927
    Abstract: Multiple laser beams selectively irradiate electrically conductive structures on or within a semiconductor substrate. The structures are arranged in a plurality of substantially parallel rows extending in a generally lengthwise direction. One method propagates first and second laser beams along respective first and second propagation paths having respective first and second axes incident at respective first and second locations on or within the semiconductor substrate at a given time. The first and second locations are either on a structure in their respective rows or between two adjacent structures in their respective rows, which are distinct. The second location is offset from the first location by some amount in the lengthwise direction of the rows. The method moves the laser beam axes substantially in unison in the lengthwise direction of the rows relative to the semiconductor substrate, so as to selectively irradiate structures in the rows with the laser beams.
    Type: Grant
    Filed: February 4, 2005
    Date of Patent: October 14, 2008
    Assignee: Electron Scientific Industries, Inc.
    Inventors: Kelly J. Bruland, Brian W. Baird, Ho Wai Lo, Stephen N. Swaringen
  • Patent number: 7425471
    Abstract: Methods and systems selectively irradiate structures on or within a semiconductor substrate using a plurality of laser beams. The structures are arranged in a row extending in a generally lengthwise direction. The method generates a first laser beam that propagates along a first laser beam axis that intersects the semiconductor substrate and a second laser beam that propagates along a second laser beam axis that intersects the semiconductor substrate. The method directs the first and second laser beams onto distinct first and second structures in the row. The second spot is offset from the first spot by some amount in a direction perpendicular to the lengthwise direction of the row. The method moves the first and second laser beam axes relative to the semiconductor substrate along the row substantially in unison in a direction substantially parallel to the lengthwise direction of the row.
    Type: Grant
    Filed: February 4, 2005
    Date of Patent: September 16, 2008
    Assignee: Electro Scientific Industries, Inc.
    Inventors: Kelly J. Bruland, Brian W. Baird, Ho Wai Lo, Stephen N. Swaringen, Frank G. Evans
  • Patent number: 7423818
    Abstract: A method of suppressing distortion of a working laser beam directed for incidence on a target specimen presented for processing by a laser link processing system uses a spatial filter to remove stray light-induced distortion from the working laser beam.
    Type: Grant
    Filed: May 24, 2006
    Date of Patent: September 9, 2008
    Assignee: Electro Scientific Industries, Inc.
    Inventors: David Martin Hemenway, Brady Nilsen, Ho Wai Lo, Keith Grant
  • Publication number: 20080203071
    Abstract: A laser pulse with a specially tailored temporal power profile, instead of a conventional temporal shape or substantially square shape, severs an IC link. The specially tailored laser pulse preferably has either an overshoot at the beginning of the laser pulse or a spike peak within the duration of the laser pulse. The timing of the spike peak is preferably set ahead of the time when the link is mostly removed. A specially tailored laser pulse power profile allows the use of a wider laser pulse energy range and shorter laser wavelengths, such as the green and UV, to sever the links without appreciable damage to the substrate and passivation structure material located on either side of and underlying the links.
    Type: Application
    Filed: March 20, 2008
    Publication date: August 28, 2008
    Applicant: Electro Scientific Industries, Inc.
    Inventors: Yunlong Sun, Richard Harris, Ho Wai Lo, Brian Baird, Jay Johnson, Robert F. Hainsey
  • Publication number: 20080121627
    Abstract: Methods and systems selectively irradiate structures on or within a semiconductor substrate using multiple laser beams. The structures may be laser-severable conductive links, and the purpose of the irradiation may be to sever selected links.
    Type: Application
    Filed: October 30, 2007
    Publication date: May 29, 2008
    Applicant: Electro Scientific Industries, Inc.
    Inventors: Kelly J. Bruland, Stephen N. Swaringen, Brian W. Baird, Ho Wai Lo, David Martin Hemenway, Brady Nilsen
  • Publication number: 20080124816
    Abstract: Methods and systems selectively irradiate structures on or within a semiconductor substrate using multiple laser beams. The structures may be laser-severable conductive links, and the purpose of the irradiation may be to sever selected links.
    Type: Application
    Filed: October 30, 2007
    Publication date: May 29, 2008
    Applicant: Electro Scientific Industries, Inc.
    Inventors: Kelly J. Bruland, Stephen N. Swaringen, Brian W. Baird, Ho Wai Lo, David Martin Hemenway
  • Patent number: 7348516
    Abstract: A laser pulse with a specially tailored temporal power profile, instead of a conventional temporal shape or substantially square shape, severs an IC link. The specially tailored laser pulse preferably has either an overshoot at the beginning of the laser pulse or a spike peak within the duration of the laser pulse. The timing of the spike peak is preferably set ahead of the time when the link is mostly removed. A specially tailored laser pulse power profile allows the use of a wider laser pulse energy range and shorter laser wavelengths, such as the green and UV, to sever the links without appreciable damage to the substrate and passivation structure material located on either side of and underlying the links.
    Type: Grant
    Filed: August 18, 2004
    Date of Patent: March 25, 2008
    Assignee: Electro Scientific Industries, Inc.
    Inventors: Yunlong Sun, Richard Harris, Ho Wai Lo, Brian Baird, Jay Johnson, Robert F. Hainsey
  • Publication number: 20080023447
    Abstract: A method of and system for forming two laser processing beams with controlled stability at a target specimen work surface includes first and second mutually coherent laser beams propagating along separate first and second beam paths that are combined to perform an optical property adjustment. The combined laser beams are separated into third and fourth laser beams propagating along separate beam paths and including respective third and fourth main beam components, and one of the third and fourth laser beams contributes a leakage component that copropagates in mutual temporal coherence with the main beam component of the other of the third and fourth laser beams. An effect of mutual temporal coherence of the leakage component and the other main beam component with which the leakage component copropagates is reduced through acousto-optic modulation frequency shifts or through incorporation of an optical path length difference in the two beams.
    Type: Application
    Filed: July 31, 2006
    Publication date: January 31, 2008
    Inventors: Douglas Earl Holmgren, Ho Wai Lo, Philip Mitchell Conklin
  • Patent number: 6816294
    Abstract: Laser beam positioners (300, 340) employ a steering mirror (236, 306) that performs small-angle deflection of a laser beam (270) to compensate for cross-axis (110) settling errors of a positioner stage (302). A two-axis mirror is preferred because either axis of the positioner stages may be used for performing work. In one embodiment, the steering mirror is used for error correction only without necessarily requiring coordination with the positioner stage position commands. A fast steering mirror employing a flexure mechanism and piezoelectric actuators to tip and tilt the mirror is preferred in semiconductor link processing (“SLP”) applications. This invention compensates for cross-axis settling time, resulting in increased SLP system throughput and accuracy while simplifying complexity of the positioner stages because the steering mirror corrections relax the positioner stage servo driving requirements.
    Type: Grant
    Filed: February 15, 2002
    Date of Patent: November 9, 2004
    Assignee: Electro Scientific Industries, Inc.
    Inventors: Mark Unrath, Kelly Bruland, Ho Wai Lo, Stephen Swaringen
  • Patent number: 6593542
    Abstract: A Q-switched, diode-pumped, solid-state (DPSS) laser (54) employs harmonic generation through nonlinear crystals (72) to generate UV light (74) for both link processing and target alignment. The type and geometry of the nonlinear crystals (72) are selected, and their temperatures are precisely controlled, to produce focused spot sizes with excellent beam quality for severing of IC fuses. A fraction of the laser output (56) can be utilized in a secondary target alignment system (50). An imaging optics module (52) may be employed to further enhance the shape quality of either or both of the secondary and primary beams. Each beam passes through a detection module (100) that measures the incident and reflected light. The two beams pass through a common combiner to facilitate calibration and alignment of the beams and subsequent link processing.
    Type: Grant
    Filed: July 11, 2001
    Date of Patent: July 15, 2003
    Assignee: Electro Scientific Industries, Inc.
    Inventors: Brian W. Baird, Brady E. Nilsen, Ho Wai Lo
  • Publication number: 20020117481
    Abstract: Laser beam positioners (300, 340) employ a steering mirror (236, 306) that performs small-angle deflection of a laser beam (270) to compensate for cross-axis (110) settling errors of a positioner stage (302). A two-axis mirror is preferred because either axis of the positioner stages may be used for performing work. In one embodiment, the steering mirror is used for error correction only without necessarily requiring coordination with the positioner stage position commands. A fast steering mirror employing a flexure mechanism and piezoelectric actuators to tip and tilt the mirror is preferred in semiconductor link processing (“SLP”) applications. This invention compensates for cross-axis settling time, resulting in increased SLP system throughput and accuracy while simplifying complexity of the positioner stages because the steering mirror corrections relax the positioner stage servo driving requirements.
    Type: Application
    Filed: February 15, 2002
    Publication date: August 29, 2002
    Inventors: Mark Unrath, Kelly Bruland, Ho Wai Lo, Stephen Swaringen
  • Publication number: 20020005396
    Abstract: A Q-switched, diode-pumped, solid-state (DPSS) laser (54) employs harmonic generation through nonlinear crystals (72) to generate UV light (74) for both link processing and target alignment. The type and geometry of the nonlinear crystals (72) are selected, and their temperatures are precisely controlled, to produce focused spot sizes with excellent beam quality for severing of IC fuses. A fraction of the laser output (56) can be utilized in a secondary target alignment system (50). An imaging optics module (52) may be employed to further enhance the shape quality of either or both of the secondary and primary beams. Each beam passes through a detection module (100) that measures the incident and reflected light. The two beams pass through a common combiner to facilitate calibration and alignment of the beams and subsequent link processing.
    Type: Application
    Filed: July 11, 2001
    Publication date: January 17, 2002
    Inventors: Brian W. Baird, Brady E. Nilsen, Ho Wai Lo