Patents by Inventor Cheng C. Kao

Cheng C. Kao 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: 8673073
    Abstract: A method for purifying silicon bearing materials for photovoltaic applications includes providing metallurgical silicon into a crucible apparatus. The metallurgical silicon is subjected to at least a thermal process to cause the metallurgical silicon to change in state from a first state to a second state, the second stage being a molten state not exceeding 1500 Degrees Celsius. At least a first portion of impurities is caused to be removed from the metallurgical silicon in the molten state. The molten metallurgical silicon is cooled from a lower region to an upper region to cause the lower region to solidify while a second portion of impurities segregate and accumulate in a liquid state region. The liquid state region is solidified to form a resulting silicon structure having a purified region and an impurity region. The purified region is characterized by a purity of greater than 99.9999%.
    Type: Grant
    Filed: July 3, 2012
    Date of Patent: March 18, 2014
    Inventors: Masahiro Hoshino, Cheng C. Kao
  • Patent number: 8524188
    Abstract: A method includes transferring a raw silicon material in a crucible and subjecting the raw silicon material in the crucible to thermal energy to form a melted silicon material at a temperature of less than 1400 Degrees Celsius, the melted silicon material having an exposed region bounded by an interior region of the crucible, subjecting an exposed inner region of the melted silicon material to an energy source to include an arc heater configured above the exposed region and to be spaced by a gap between the exposed region and a muzzle region of the arc heater to form a determined temperature profile within a vicinity of an inner region of the exposed melted silicon material while maintaining outer regions of the melted silicon material at a temperature below a melting point of the crucible, and removing impurities from the melted silicon material to form higher purity silicon.
    Type: Grant
    Filed: June 29, 2012
    Date of Patent: September 3, 2013
    Inventors: Masahiro Hoshino, Cheng C. Kao
  • Patent number: 8501140
    Abstract: A method improves yield of an upgraded metallurgical-grade (UMG) silicon purification process. In the UMG silicon purification process, in a reaction chamber, purification is performed on a silicon melt therein by one, all or a plurality of the following techniques in the same apparatus at the same time. The techniques includes a crucible ratio approach, the addition of water-soluble substances, the control of power, the control of vacuum pressure, the upward venting of exhaust, isolation by high-pressure gas jet, and carbon removal by sandblasting, thereby reducing oxygen, carbon and other impurities in the silicon melt, meeting a high-purity silicon standard of solar cells, increasing yield while maintaining low cost, and avoiding EMF reduction over time. An exhaust venting device for the purification process allows exhaust to be vented from the top of the reactor chamber, thereby avoiding backflow of exhaust into the silicon melt and erosion of the reactor.
    Type: Grant
    Filed: June 28, 2012
    Date of Patent: August 6, 2013
    Inventors: Masahiro Hoshino, Cheng C. Kao
  • Patent number: 8461487
    Abstract: A system for forming high quality silicon material, e.g., polysilicon. In a specific embodiment, the melted material comprises a silicon material and an impurity, e.g., phosphorous species. The system includes a crucible having an interior region. In a specific embodiment, the crucible is made of a suitable material such as a quartz material or others. The quartz material is capable of withstanding a temperature of at least 1400 Degrees Celsius for processing silicon. In a specific embodiment, the crucible is configured in an upright position and has an open region to expose a melted material. In a specific embodiment, the present system has an energy source. Such energy source may be an arc heater or other suitable heating device, including multiple heating devices, which may be the same or different.
    Type: Grant
    Filed: February 8, 2011
    Date of Patent: June 11, 2013
    Inventors: Masahiro Hoshino, Cheng C. Kao
  • Publication number: 20120279440
    Abstract: A method for purifying silicon bearing materials for photovoltaic applications includes providing metallurgical silicon into a crucible apparatus. The metallurgical silicon is subjected to at least a thermal process to cause the metallurgical silicon to change in state from a first state to a second state, the second stage being a molten state not exceeding 1500 Degrees Celsius. At least a first portion of impurities is caused to be removed from the metallurgical silicon in the molten state. The molten metallurgical silicon is cooled from a lower region to an upper region to cause the lower region to solidify while a second portion of impurities segregate and accumulate in a liquid state region. The liquid state region is solidified to form a resulting silicon structure having a purified region and an impurity region. The purified region is characterized by a purity of greater than 99.9999%.
    Type: Application
    Filed: July 3, 2012
    Publication date: November 8, 2012
    Inventors: Masahiro Hoshino, Cheng C. Kao
  • Publication number: 20120279439
    Abstract: A method improves yield of an upgraded metallurgical-grade (UMG) silicon purification process. In the UMG silicon purification process, in a reaction chamber, purification is performed on a silicon melt therein by one, all or a plurality of the following techniques in the same apparatus at the same time. The techniques includes a crucible ratio approach, the addition of water-soluble substances, the control of power, the control of vacuum pressure, the upward venting of exhaust, isolation by high-pressure gas jet, and carbon removal by sandblasting, thereby reducing oxygen, carbon and other impurities in the silicon melt, meeting a high-purity silicon standard of solar cells, increasing yield while maintaining low cost, and avoiding EMF reduction over time. An exhaust venting device for the purification process allows exhaust to be vented from the top of the reactor chamber, thereby avoiding backflow of exhaust into the silicon melt and erosion of the reactor.
    Type: Application
    Filed: June 28, 2012
    Publication date: November 8, 2012
    Inventors: Masahiro HOSHINO, Cheng C. Kao
  • Publication number: 20120275985
    Abstract: A method includes transferring a raw silicon material in a crucible and subjecting the raw silicon material in the crucible to thermal energy to form a melted silicon material at a temperature of less than 1400 Degrees Celsius, the melted silicon material having an exposed region bounded by an interior region of the crucible, subjecting an exposed inner region of the melted silicon material to an energy source to include an arc heater configured above the exposed region and to be spaced by a gap between the exposed region and a muzzle region of the arc heater to form a determined temperature profile within a vicinity of an inner region of the exposed melted silicon material while maintaining outer regions of the melted silicon material at a temperature below a melting point of the crucible, and removing impurities from the melted silicon material to form higher purity silicon.
    Type: Application
    Filed: June 29, 2012
    Publication date: November 1, 2012
    Inventors: Masahiro HOSHINO, Cheng C. KAO
  • Patent number: 8257492
    Abstract: A method for purifying silicon bearing materials for photovoltaic applications includes providing metallurgical silicon into a crucible apparatus. The metallurgical silicon is subjected to at least a thermal process to cause the metallurgical silicon to change in state from a first state to a second state, the second stage being a molten state not exceeding 1500 Degrees Celsius. At least a first portion of impurities is caused to be removed from the metallurgical silicon in the molten state. The molten metallurgical silicon is cooled from a lower region to an upper region to cause the lower region to solidify while a second portion of impurities segregate and accumulate in a liquid state region. The liquid state region is solidified to form a resulting silicon structure having a purified region and an impurity region. The purified region is characterized by a purity of greater than 99.9999%.
    Type: Grant
    Filed: November 16, 2010
    Date of Patent: September 4, 2012
    Inventors: Masahiro Hoshino, Cheng C. Kao
  • Patent number: 8236265
    Abstract: The present invention provides a method for forming high quality silicon material, e.g., polysilicon. The method includes transferring a raw silicon material in a crucible having an interior region. The crucible is made of a quartz or other suitable material, which is capable of withstanding a temperature of at least 1400 Degrees Celsius. The method includes subjecting the raw silicon material in the crucible to thermal energy to cause the raw silicon material to be melted into a liquid state to form a melted material at a temperature of less than about 1400 Degrees Celsius. Preferably, the melted material has an exposed region bounded by the interior region of the crucible.
    Type: Grant
    Filed: February 9, 2011
    Date of Patent: August 7, 2012
    Inventors: Masahiro Hoshino, Cheng C. Kao
  • Patent number: 8236266
    Abstract: A method for improving yield of an upgraded metallurgical-grade (UMG) silicon purification process is disclosed. In the UMG silicon (UMGSi) purification process, in a reaction chamber, purification is performed on a silicon melt therein by one, all or a plurality of the following techniques in the same apparatus at the same time, including: a crucible ratio approach, the addition of water-soluble substances, the control of power, the control of vacuum pressure, the upward venting of exhaust, isolation by high-pressure gas jet, and carbon removal by sandblasting, thereby reducing oxygen, carbon and other impurities in the silicon melt, meeting a high-purity silicon standard of solar cells, increasing yield while maintaining low cost, and avoiding EMF reduction over time. An exhaust venting device for purification processes is also disclosed, which allows exhaust to be vented from the top of the reactor chamber, thereby avoiding backflow of exhaust into the silicon melt and erosion of the reactor.
    Type: Grant
    Filed: July 20, 2011
    Date of Patent: August 7, 2012
    Inventors: Masahiro Hoshino, Cheng C. Kao
  • Publication number: 20120020865
    Abstract: A method for improving yield of an upgraded metallurgical-grade (UMG) silicon purification process is disclosed. In the UMG silicon (UMGSi) purification process, in a reaction chamber, purification is performed on a silicon melt therein by one, all or a plurality of the following techniques in the same apparatus at the same time, including: a crucible ratio approach, the addition of water-soluble substances, the control of power, the control of vacuum pressure, the upward venting of exhaust, isolation by high-pressure gas jet, and carbon removal by sandblasting, thereby reducing oxygen, carbon and other impurities in the silicon melt, meeting a high-purity silicon standard of solar cells, increasing yield while maintaining low cost, and avoiding EMF reduction over time. An exhaust venting device for purification processes is also disclosed, which allows exhaust to be vented from the top of the reactor chamber, thereby avoiding backflow of exhaust into the silicon melt and erosion of the reactor.
    Type: Application
    Filed: July 20, 2011
    Publication date: January 26, 2012
    Inventors: Masahiro Hoshino, Cheng C. Kao
  • Patent number: 8066981
    Abstract: The invention relates to compositions and methods related to Toll-like receptor (TLR) polypeptides. In some embodiments, the invention relates to managing TLR3 related diseases. In further embodiments, the invention relates to methods of preventing and treating inflammation. In some embodiments, the invention relates to antagonists of TLR3, to amino acid sequences that act as dominant negative molecules, and to nucleic acid sequences that encode said amino acid sequences. In additional embodiments, the invention relates to the manipulation of biological materials to evaluate TLR3 activity.
    Type: Grant
    Filed: November 14, 2007
    Date of Patent: November 29, 2011
    Assignee: The Texas A & M University System
    Inventors: Cheng C. Kao, Ranjith Kumar Tharachaparamba
  • Publication number: 20110198336
    Abstract: A system for forming high quality silicon material, e.g., polysilicon. In a specific embodiment, the melted material comprises a silicon material and an impurity, e.g., phosphorous species. The system includes a crucible having an interior region. In a specific embodiment, the crucible is made of a suitable material such as a quartz material or others. The quartz material is capable of withstanding a temperature of at least 1400 Degrees Celsius for processing silicon. In a specific embodiment, the crucible is configured in an upright position and has an open region to expose a melted material. In a specific embodiment, the present system has an energy source. Such energy source may be an arc heater or other suitable heating device, including multiple heating devices, which may be the same or different.
    Type: Application
    Filed: February 8, 2011
    Publication date: August 18, 2011
    Inventors: Masahiro Hoshino, Cheng C. Kao
  • Publication number: 20110200514
    Abstract: The present invention provides a method for forming high quality silicon material, e.g., polysilicon. The method includes transferring a raw silicon material in a crucible having an interior region. The crucible is made of a quartz or other suitable material, which is capable of withstanding a temperature of at least 1400 Degrees Celsius. The method includes subjecting the raw silicon material in the crucible to thermal energy to cause the raw silicon material to be melted into a liquid state to form a melted material at a temperature of less than about 1400 Degrees Celsius. Preferably, the melted material has an exposed region bounded by the interior region of the crucible.
    Type: Application
    Filed: February 9, 2011
    Publication date: August 18, 2011
    Inventors: Masahiro HOSHINO, Cheng C. Kao
  • Publication number: 20110114012
    Abstract: A method for purifying silicon bearing materials for photovoltaic applications includes providing metallurgical silicon into a crucible apparatus. The metallurgical silicon is subjected to at least a thermal process to cause the metallurgical silicon to change in state from a first state to a second state, the second stage being a molten state not exceeding 1500 Degrees Celsius. At least a first portion of impurities is caused to be removed from the metallurgical silicon in the molten state. The molten metallurgical silicon is cooled from a lower region to an upper region to cause the lower region to solidify while a second portion of impurities segregate and accumulate in a liquid state region. The liquid state region is solidified to form a resulting silicon structure having a purified region and an impurity region. The purified region is characterized by a purity of greater than 99.9999%.
    Type: Application
    Filed: November 16, 2010
    Publication date: May 19, 2011
    Inventors: Masahiro HOSHINO, Cheng C. Kao
  • Publication number: 20090142300
    Abstract: The invention relates to compositions and methods related to Toll-like receptor (TLR) polypeptides. In some embodiments, the invention relates to managing TLR3 related diseases. In further embodiments, the invention relates to methods of preventing and treating inflammation. In some embodiments, the invention relates to antagonists of TLR3, to amino acid sequences that act as dominant negative molecules, and to nucleic acid sequences that encode said amino acid sequences. In additional embodiments, the invention relates to the manipulation of biological materials to evaluate TLR3 activity.
    Type: Application
    Filed: November 14, 2007
    Publication date: June 4, 2009
    Inventors: Cheng C. Kao, Ranjith Kumar Tharachaparamba