Patents by Inventor Chien M. Wai

Chien M. Wai 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: 20080136028
    Abstract: The invention includes a method of forming a metal-containing film over a surface of a semiconductor substrate. The surface is exposed to a supercritical fluid. The supercritical fluid has H2, at least one H2-activating catalyst, and at least one metal-containing precursor dispersed therein. A metal-containing film is formed across the surface of the semiconductor substrate from metal of the at least one metal-containing precursor. The invention also includes semiconductor constructions having metal-containing layers which include one or more of copper, cobalt, gold and nickel in combination with one or more of palladium, platinum, iridium, rhodium and ruthenium.
    Type: Application
    Filed: October 25, 2002
    Publication date: June 12, 2008
    Inventors: Chien M. Wai, Hiroyuki Ohde, Steve Kramer
  • Publication number: 20080134837
    Abstract: Embodiments of a method and a system for recovering a metal, such as uranium, from a metal-containing material are disclosed. The metal-containing material is exposed to an extractant containing a liquid or supercritical-fluid solvent and an acid-base complex including an oxidizing agent and a complexing agent. Batches of the metal-containing material are moved through a series of stations while the extractant is moved through the stations in the opposite direction. After the extraction step, the metal is separated from the solvent, the complexing agent and/or other metals by exposing the extract to a stripping agent in a countercurrent stripping column. The complexing agent and the solvent exit the column and are separated from each other by reducing the pressure. The recovered complexing agent is recharged with fresh oxidizing agent and recombined with fresh or recovered solvent to form a recovered extractant, which is distributed through the extraction stations.
    Type: Application
    Filed: January 12, 2006
    Publication date: June 12, 2008
    Applicant: IDAHO RESEARCH FOUNDATION, INC.
    Inventors: Chien M. Wai, Sydney S. Koegler
  • Publication number: 20080115627
    Abstract: A method for separating metals from metal-containing materials by extraction without generating large quantities of liquid waste is disclosed. Also disclosed is an extractant composition for use with this method. The method comprises exposing a metal-containing material to a solvent, such as supercritical carbon dioxide, an acid-base complex, and a chelating agent that is not a component of the acid-base complex. The metal is released into the solvent by a combination of oxidation by an oxidizing agent in the acid-base complex and chelation by the chelating agent. The oxidizing agent in the acid-base complex is solubilized by a solubilizing agent. The disclosed method and composition have many applications and are particularly well suited for the extraction of transition metals, including, but not limited to, platinum group metals, nom a metals and coinage metals. Applications include the recovery of metals from scrap materials and the planarization of semiconductor structures.
    Type: Application
    Filed: August 18, 2005
    Publication date: May 22, 2008
    Inventors: Joanna S. Wang, Chien M. Wai
  • Patent number: 7341947
    Abstract: The invention includes a method of forming a metal-containing film over a surface of a semiconductor substrate. The surface is exposed to a supercritical fluid. The supercritical fluid has H2, at least one H2-activating catalyst, and at least one metal-containing precursor dispersed therein. A metal-containing film is formed across the surface of the semiconductor substrate from metal of the at least one metal-containing precursor. The invention also includes semiconductor constructions having metal-containing layers which include one or more of copper, cobalt, gold and nickel in combination with one or more of palladium, platinum, iridium, rhodium and ruthenium.
    Type: Grant
    Filed: May 25, 2004
    Date of Patent: March 11, 2008
    Assignee: Micron Technology, Inc.
    Inventors: Chien M. Wai, Hiroyuki Ohde, Steve Kramer
  • Patent number: 7128840
    Abstract: Improved methods for the extraction or dissolution of metals, metalloids or their oxides, especially lanthanides, actinides, uranium or their oxides, into supercritical solvents containing an extractant are disclosed. The disclosed embodiments specifically include enhancing the extraction or dissolution efficiency with ultrasound. The present methods allow the direct, efficient dissolution of UO2 or other uranium oxides without generating any waste stream or by-products.
    Type: Grant
    Filed: March 25, 2003
    Date of Patent: October 31, 2006
    Assignee: Idaho Research Foundation, Inc.
    Inventors: Chien M. Wai, Youichi Enokida
  • Patent number: 6653236
    Abstract: The invention includes a method of forming a metal-containing film over a surface of a semiconductor substrate. The surface is exposed to a supercritical fluid. The supercritical fluid has H2, at least one H2-activating catalyst, and at least one metal-containing precursor dispersed therein. A metal-containing film is formed across the surface of the semiconductor substrate from metal of the at least one metal-containing precursor. The invention also includes semiconductor constructions having metal-containing layers which include one or more of copper, cobalt, gold and nickel in combination with one or more of palladium, platinum, iridium, rhodium and ruthenium.
    Type: Grant
    Filed: March 29, 2002
    Date of Patent: November 25, 2003
    Assignee: Micron Technology, Inc.
    Inventors: Chien M. Wai, Hiroyuki Ohde, Steve Kramer
  • Publication number: 20030183938
    Abstract: The invention includes a method of forming a metal-containing film over a surface of a semiconductor substrate. The surface is exposed to a supercritical fluid. The supercritical fluid has H2, at least one H2-activating catalyst, and at least one metal-containing precursor dispersed therein. A metal-containing film is formed across the surface of the semiconductor substrate from metal of the at least one metal-containing precursor. The invention also includes semiconductor constructions having metal-containing layers which include one or more of copper, cobalt, gold and nickel in combination with one or more of palladium, platinum, iridium, rhodium and ruthenium.
    Type: Application
    Filed: March 29, 2002
    Publication date: October 2, 2003
    Inventors: Chien M. Wai, Hiroyuki Ohde, Steve Kramer
  • Publication number: 20030183043
    Abstract: Improved methods for the extraction or dissolution of metals, metalloids or their oxides, especially lanthanides, actinides, uranium or their oxides, into supercritical solvents containing an extractant are disclosed. The disclosed embodiments specifically include enhancing the extraction or dissolution efficiency with ultrasound. The present methods allow the direct, efficient dissolution of UO2 or other uranium oxides without generating any waste stream or by-products.
    Type: Application
    Filed: March 25, 2003
    Publication date: October 2, 2003
    Inventors: Chien M. Wai, Youichi Enokida
  • Patent number: 6524628
    Abstract: Pressurized Water Extraction (PWE) is a method for extracting materials from plants by exposing a plant sample to a pressurized liquid aqueous composition. The exposure may be performed statically, dynamically, or both. For example, the sample may be exposed to a liquid aqueous composition at a temperature of from about 0° C. to about 100° C. and a pressure between about 25 atm and about 1000 atm, more typically from about 50 atm to about 200 atm. Plant materials are selectively isolated in the aqueous compositions by this method more effectively than prior methods. Moreover, the present methods provide facile extraction of thermally labile compounds, such as bilobalides from Gingko leaves.
    Type: Grant
    Filed: November 6, 2000
    Date of Patent: February 25, 2003
    Assignee: Idaho Research Foundation, Inc.
    Inventors: Chien M. Wai, Qingyong Lang
  • Patent number: 6187911
    Abstract: A method for separating a desired metal or metalloi from impurities using a supercritical extraction process based on solubility differences between the components, as well as the ability to vary the solvent power of the supercritical fluid, is described. The use of adduct-forming agents, such as phosphorous-containing ligands, to separate metal or metalloid chelates in such processes is further disclosed. In preferred embodiments, the extraction solvent is supercritical carbon dioxide and the chelating agent is selected from the group consisting of &bgr;-diketones; phosphine oxides, such as trialkylphosphine oxides, triarylphosphine oxides and alkylarylphosphine oxides; phosphinic acids; carboxylic acids; phosphates, such as trialkylphosphates, triarylphosphates and alkylarylphosphates; crown ethers; dithiocarbamates; phosphine sulfides; phosphorothioic acids; thiophosphinic acids; halogenated analogs of these chelating agents; and mixtures of these chelating agents.
    Type: Grant
    Filed: May 7, 1999
    Date of Patent: February 13, 2001
    Assignee: Idaho Research Foundation, Inc.
    Inventors: Chien M. Wai, Neil G. Smart, Cindy Phelps
  • Patent number: 6132491
    Abstract: A method for dissociating metal-ligand complexes in a supercritical fluid by treating the metal-ligand complex with heat and/or reducing or oxidizing agents is described. Once the metal-ligand complex is dissociated, the resulting metal and/or metal oxide form fine particles of substantially uniform size. In preferred embodiments, the solvent is supercritical carbon dioxide and the ligand is a .beta.-diketone such as hexafluoroacetylacetone or dibutyldiacetate. In other preferred embodiments, the metals in the metal-ligand complex are copper, silver, gold, tungsten, titanium, tantalum, tin, or mixtures thereof. In preferred embodiments, the reducing agent is hydrogen. The method provides an efficient process for dissociating metal-ligand complexes and produces easily-collected metal particles free from hydrocarbon solvent impurities. The ligand and the supercritical fluid can be regenerated to provide an economic, efficient process.
    Type: Grant
    Filed: August 20, 1998
    Date of Patent: October 17, 2000
    Assignee: Idaho Research Foundation, Inc.
    Inventors: Chien M. Wai, Fred H. Hunt, Neil G. Smart, Yuehe Lin
  • Patent number: 6117413
    Abstract: The invention pertains to compounds which specifically bind radionuclides, and to methods of making radionuclide complexing compounds. In one aspect, the invention includes a radionuclide delivery system comprising: a) a calix[n]arene-crown-[m]-ether compound, wherein n is an integer greater than 3, and wherein m is an integer greater than 3, the calix[n]arene-crown-[m]-ether compound comprising at least two ionizable groups; and b) an antibody attached to the calix[n]arene-crown-[m]-ether compound.
    Type: Grant
    Filed: November 12, 1997
    Date of Patent: September 12, 2000
    Assignees: Battelle Memorial Institute, Idaho Research Foundation, Inc.
    Inventors: Darrell R. Fisher, Chien M. Wai, Xiaoyuan Chen
  • Patent number: 6075130
    Abstract: The invention pertains to compounds for binding lanthanide ions and actinide ions. The invention further pertains to compounds for binding radionuclides, and to methods of making radionuclide complexes. Also, the invention pertains to methods of extracting radionuclides. Additionally, the invention pertains to methods of delivering radionuclides to target locations. In one aspect, the invention includes a compound comprising: a) a calix[n]arene group, wherein n is an integer greater than 3, the calix[n]arene group comprising an upper rim and a lower rim; b) at least one ionizable group attached to the lower rim; and c) an ion selected from the group consisting of lanthanide and actinide elements bound to the ionizable group.
    Type: Grant
    Filed: November 10, 1998
    Date of Patent: June 13, 2000
    Assignees: Battelle Memorial Institute, Idaho Research Foundation, Inc.
    Inventors: Xiaoyuan Chen, Chien M. Wai, Darrell R. Fisher
  • Patent number: 5965025
    Abstract: A method of extracting metalloid and metal species from a solid or liquid material by exposing the material to a supercritical fluid solvent containing a chelating agent is described. The chelating agent forms chelates that are soluble in the supercritical fluid to allow removal of the species from the material. In preferred embodiments, the extraction solvent is supercritical carbon dioxide and the chelating agent is a fluorinated .beta.-diketone. In especially preferred embodiments the extraction solvent is supercritical carbon dioxide, and the chelating agent comprises a fluorinated .beta.-diketone and a trialkyl phosphate, or a fluorinated .beta.-diketone and a trialkylphosphine oxide. Although a trialkyl phosphate can extract lanthanides and actinides from acidic solutions, a binary mixture comprising a fluorinated .beta.-diketone and a trialkyl phosphate or a trialkylphosphine oxide tends to enhance the extraction efficiencies for actinides and lanthanides.
    Type: Grant
    Filed: January 21, 1998
    Date of Patent: October 12, 1999
    Assignee: Idaho Research Foundation, Inc.
    Inventors: Chien M. Wai, Kenneth E. Laintz
  • Patent number: 5840193
    Abstract: Methods for extracting metalloid and metal species from a solid or liquid material by exposing the material to a fluid solvent, particularly supercritical CO.sub.2, and a chelating agent are described. The chelating agent forms a chelate with the species, the chelate being soluble in the fluid to allow removal of the species from the material. In preferred embodiments the extraction solvent is supercritical CO.sub.2 and the chelating agent comprises an organophosphorous chelating agent, particularly sulfur-containing organophosphorous chelating agents, including mixtures of chelating agents. Examples of chelating agents include monothiophosphinic acid, di-thiophosphinic acid, phosphine sulfite, phosphorothioic acid, and mixtures thereof. The method provides an environmentally benign process for removing metal and metalloids from industrial waste solutions, particularly acidic solutions.
    Type: Grant
    Filed: July 26, 1996
    Date of Patent: November 24, 1998
    Assignee: Idaho Research Foundation
    Inventors: Neil G. Smart, Chien M. Wai, Yuehe Lin, Yak Hwa Kwang
  • Patent number: 5792357
    Abstract: A method of extracting metal and metalloid species from a solid or liquid substrate using a supercritical fluid solvent containing one or more chelating agents followed by back-extracting the metal and metalloid species from the metal and metalloid chelates formed thereby. The back-extraction acidic solution is performed utilizing an acidic solution. Upon sufficient exposure of the metal and metalloid chelates to the acidic solution, the metal and metalloid species are released from the chelates into the acid solution, while the chelating agent remains in the supercritical fluid solvent. The chelating agent is thereby regenerated and the metal and metalloid species recovered.
    Type: Grant
    Filed: July 26, 1996
    Date of Patent: August 11, 1998
    Assignee: Idaho Research Foundation, Inc.
    Inventors: Chien M. Wai, Neil G. Smart, Yuehe Lin
  • Patent number: 5770085
    Abstract: A method of extracting metalloid and metal species from a solid or liquid material by exposing the material to a fluid solvent, particularly supercritical carbon dioxide, containing a chelating agent is described. The chelating agent forms chelates that are soluble in the fluid to allow removal of the species from the material. In preferred embodiments, the extraction solvent is supercritical carbon dioxide and the chelating agent comprises a trialkyl phosphate, a triaryl phosphate, a trialkylphosphine oxide, a triarylphosphine oxide, or mixtures thereof. The method provides an environmentally benign process for removing contaminants from industrial waste. The method is particularly useful for extracting actinides from acidic solutions, and the process can be aided by the addition of nitrate salts. The chelate and supercritical fluid can be regenerated, and the contaminant species recovered, to provide an economic, efficient process.
    Type: Grant
    Filed: June 2, 1995
    Date of Patent: June 23, 1998
    Assignee: Idaho Research Foundation, Inc.
    Inventors: Chien M. Wai, Neil G. Smart, Yuehe Lin
  • Patent number: 5730874
    Abstract: A method of extracting metalloid and metal species from a solid or liquid material by exposing the material to a supercritical fluid solvent containing a chelating agent is described. The chelating agent forms chelates that are soluble in the supercritical fluid to allow removal of the species from the material. In preferred embodiments, the extraction solvent is supercritical carbon dioxide and the chelating agent is a fluorinated .beta.-diketone. In especially preferred embodiments the extraction solvent is supercritical carbon dioxide, and the chelating agent comprises a fluorinated .beta.-diketone and a trialkyl phosphate, or a fluorinated .beta.-diketone and a trialkylphosphine oxide. Although a trialkyl phosphate can extract lanthanides and actinides from acidic solutions, a binary mixture comprising a fluorinated .beta.-diketone and a trialkyl phosphate or a trialkylphosphine oxide tends to enhance the extraction efficiencies for actinides and lanthanides.
    Type: Grant
    Filed: June 2, 1994
    Date of Patent: March 24, 1998
    Assignee: Idaho Research Foundation, Inc.
    Inventors: Chien M. Wai, Kenneth E. Laintz
  • Patent number: 5606724
    Abstract: A method of extracting metals directly from metal oxides by exposing the oxide to a supercritical fluid solvent containing a chelating agent is described. Preferably, the metal is an actinide or a lanthanide. More preferably, the metal is uranium, thorium or plutonium. The chelating agent forms chelates that are soluble in the supercritical fluid, thereby allowing direct removal of the metal from the metal oxide. In preferred embodiments, the extraction solvent is supercritical carbon dioxide and the chelating agent is selected from the group consisting of .beta.-diketones, halogenated .beta.-diketones, phosphinic acids, halogenated phosphinic acids, carboxylic acids, halogenated carboxylic acids, and mixtures thereof. In especially preferred embodiments, at least one of the chelating agents is fluorinated. The method provides an environmentally benign process for removing metals from metal oxides without using acids or biologically harmful solvents.
    Type: Grant
    Filed: November 3, 1995
    Date of Patent: February 25, 1997
    Assignee: Idaho Research Foundation, Inc.
    Inventors: Chien M. Wai, Neil G. Smart, Cindy Phelps
  • Patent number: 5356538
    Abstract: A method of extracting metalloid and metal species from a solid or liquid material by exposing the material to a supercritical fluid solvent containing a chelating agent. The chelating agent forms chelates that are soluble in the supercritical fluid to allow removal of the species from the material. In preferred embodiments, the extraction solvent is supercritical carbon dioxide and the chelating agent is a fluorinated or lipophilic crown ether or fluorinated dithiocarbamate. The method provides an environmentally benign process for removing contaminants from industrial waste without using acids or biologically harmful solvents. The chelate and supercritical fluid can be regenerated, and the contaminant species recovered, to provide an economic, efficient process.
    Type: Grant
    Filed: October 21, 1991
    Date of Patent: October 18, 1994
    Assignee: Idaho Research Foundation, Inc.
    Inventors: Chien M. Wai, Kenneth Laintz