Patents by Inventor Tat-Kwan Yu

Tat-Kwan Yu 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: 6593226
    Abstract: Selective placement of polishing dummy feature patterns, rather than indiscriminate placement of polishing dummy feature patterns, is used. Both low frequency (hundreds of microns and larger) and high frequency (10 microns and less) of topography changes are examined. The polishing dummy feature patterns can be specifically tailored to a semiconductor device and polishing conditions used in forming the semiconductor device. When designing an integrated circuit, polishing effects for the active features can be predicted. After polishing dummy feature pattern(s) are placed into the layout, the planarity can be examined on a local level (a portion but not all of the device) and a more global level (all of the device, devices corresponding to a reticle field, or even an entire wafer).
    Type: Grant
    Filed: July 17, 2001
    Date of Patent: July 15, 2003
    Assignee: Motorola, Inc.
    Inventors: Edward O. Travis, Aykut Dengi, Sejal Chheda, Tat-Kwan Yu, Mark S. Roberton, Ruiqi Tian, Robert E. Boone, Alfred J. Reich
  • Patent number: 6396158
    Abstract: Selective placement of polishing dummy feature patterns, rather than indiscriminate placement of polishing dummy feature patterns, is used. Both low frequency (hundreds of microns and larger) and high frequency (10 microns and less) of topography changes are examined. The polishing dummy feature patterns can be specifically tailored to a semiconductor device and polishing conditions used in forming the semiconductor device. When designing an integrated circuit, polishing effects for the active features can be predicted. After polishing dummy feature pattern(s) are placed into the layout, the planarity can be examined on a local level (a portion but not all of the device) and a more global level (all of the device, devices corresponding to a reticle field, or even an entire wafer).
    Type: Grant
    Filed: June 29, 1999
    Date of Patent: May 28, 2002
    Assignee: Motorola Inc.
    Inventors: Edward O. Travis, Aykut Dengi, Sejal Chheda, Tat-Kwan Yu, Mark S. Roberton, Ruiqi Tian
  • Publication number: 20020050655
    Abstract: Selective placement of polishing dummy feature patterns, rather than indiscriminate placement of polishing dummy feature patterns, is used. Both low frequency (hundreds of microns and larger) and high frequency (10 microns and less) of topography changes are examined. The polishing dummy feature patterns can be specifically tailored to a semiconductor device and polishing conditions used in forming the semiconductor device. When designing an integrated circuit, polishing effects for the active features can be predicted. After polishing dummy feature pattern(s) are placed into the layout, the planarity can be examined on a local level (a portion but not all of the device) and a more global level (all of the device, devices corresponding to a reticle field, or even an entire wafer).
    Type: Application
    Filed: July 17, 2001
    Publication date: May 2, 2002
    Inventors: Edward O. Travis, Aykut Dengi, Sejal Chheda, Tat-Kwan Yu, Mark S. Roberton, Ruiqi Tian, Robert E. Boone, Alfred J. Reich
  • Patent number: 5674352
    Abstract: The present invention includes a modified polishing pad and methods on how to form and use the polishing pad. In one embodiment, a modified polishing pad is formed similar to polishing substrates except that the modifying pressure should be large enough to mechanically deform part of the polishing pad. The modifying pressure is typically at least 10 pounds per square inch. The materials used to modify the pad should be hard with a smooth surface. Examples of these materials are metals, dielectrics, and semiconductors. After modifying the polishing pad, it may be used to polish semiconductor substrates. Compared to a fresh pad, the modified polishing pad should have a higher planarization efficiency and be less likely to cause corner rounding of a patterned layer adjacent to an opening.
    Type: Grant
    Filed: May 15, 1995
    Date of Patent: October 7, 1997
    Assignee: Motorola, Inc.
    Inventors: Chris Chang Yu, Tat-Kwan Yu
  • Patent number: 5628862
    Abstract: A mold is used to form a polishing pad, wherein the surface of the polishing side of the polishing pad is determined by a primary surface of the mold. Features along the polishing side of a polishing pad may take any one of several different shapes. Channels along the polishing side of the polishing pad allow a smaller pore size to be used. The mold allows more control over the surface of the polishing side, which in turn give more control over polishing characteristics.
    Type: Grant
    Filed: May 18, 1995
    Date of Patent: May 13, 1997
    Assignee: Motorola, Inc.
    Inventors: Tat-Kwan Yu, Chris C. Yu
  • Patent number: 5531861
    Abstract: A chemical-mechanical-polishing process in which energy is imparted to a polishing pad (18) dislodging particles (46), which are removed by vacuum withdrawal to continuously clean the surface of the polishing pad (14). Energy is imparted to polishing pad (18) by either sonic energy from acoustic waves, or by physical impaction. The acoustic waves are generated by submerging a transducer (28) in the polishing slurry (18). The transducer (28) is powered by a voltage amplifier (30) coupled to a computer controlled-frequency generator (32). The acoustic wave frequency is adjusted by the frequency generator (32) to induce sonic vibration in the polishing pad (14) such that particles (46) are continuously dislodged from polishing pad (14). Physical impaction is performed by an impaction tool (48) coupled to a vacuum head (33).
    Type: Grant
    Filed: January 17, 1995
    Date of Patent: July 2, 1996
    Assignee: Motorola, Inc.
    Inventors: Chris C. Yu, Tat-Kwan Yu
  • Patent number: 5441598
    Abstract: A mold is used to form a polishing pad, wherein the surface of the polishing side of the polishing pad is determined by a primary surface of the mold. Features along the polishing side of a polishing pad may take any one of several different shapes. Channels along the polishing side of the polishing pad allow a smaller pore size to be used. The mold allows more control over the surface of the polishing side, which in turn give more control over polishing characteristics.
    Type: Grant
    Filed: December 16, 1993
    Date of Patent: August 15, 1995
    Assignee: Motorola, Inc.
    Inventors: Tat-Kwan Yu, Chris C. Yu
  • Patent number: 5399234
    Abstract: A chemical-mechanical-polishing process in which acoustic waves are generated in the polishing slurry (18) to enable detection of an end-point in the polishing process, and to continuously clean the surface of a polishing pad (14) in a polishing apparatus (10). Acoustic waves are generated in the polishing slurry (18) by submerging a transducer (28) in the polishing slurry (18). The transducer (28) is powered by a voltage amplifier (30) coupled to a frequency generator (32). The frequency of the acoustic waves is adjusted by the frequency generator (32) to obtain optimum wave generation in the polishing slurry (18). The end-point of the polishing process is detected by a change in the acoustic wave velocity in the polishing slurry (18), which occurs when the slurry composition changes at end-point. The wave velocity is monitored by a receiver (34) submerged in the polishing slurry (18) at a predetermined distance from the transducer (28).
    Type: Grant
    Filed: September 29, 1993
    Date of Patent: March 21, 1995
    Assignee: Motorola Inc.
    Inventors: Chris C. Yu, Tat-Kwan Yu, Jeffrey L. Klein