Patents by Inventor Thomas Anand Ponnuswamy

Thomas Anand Ponnuswamy 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: 20190122890
    Abstract: A method of electroplating a metal into features of a partially fabricated electronic device on a substrate is provided. The method includes (a) electroplating the metal into the features, to partially fill the features by a bottom up fill mechanism, while contacting the features with a first electroplating bath having a first composition and comprising ions of the metal; (b) thereafter, electroplating more of the metal into the features, to further fill the features, while contacting the features with a second electroplating bath having a second composition, which is different than the first composition, and comprises the ions of the metal; and (c) removing the substrate from an electroplating tool where operation (b) was performed.
    Type: Application
    Filed: October 19, 2018
    Publication date: April 25, 2019
    Inventors: Kari Thorkelsson, Nirmal Shankar, Sigamani, Bryan L. Buckalew, Steven T. Mayer, Thomas Anand Ponnuswamy
  • Patent number: 10128102
    Abstract: Disclosed are pre-wetting apparatus designs and methods for cleaning solid contaminants from substrates prior to through resist deposition of metal. In some embodiments, a pre-wetting apparatus includes a process chamber having a substrate holder, and at least one nozzle located directly above the wafer substrate and configured to deliver pre-wetting liquid (e.g., degassed deionized water) onto the substrate at a grazing angle of between about 5 and 45 degrees. In some embodiments the nozzle is a fan nozzle configured to deliver the liquid to the center of the substrate, such that the liquid first impacts the substrate in the vicinity of the center and then flows over the center of the substrate. In some embodiments the substrate is rotated unidirectionally or bidirectionally during pre-wetting with multiple accelerations and decelerations, which facilitate removal of contaminants.
    Type: Grant
    Filed: February 3, 2017
    Date of Patent: November 13, 2018
    Assignee: Novellus Systems, Inc.
    Inventors: Lee Peng Chua, Bryan L. Buckalew, Thomas Anand Ponnuswamy, Brian Paul Blackman, Chad Michael Hosack, Steven T. Mayer
  • Patent number: 9746427
    Abstract: The embodiments herein relate to methods and apparatus for detecting whether unwanted metallic deposits are present on a bottom of a substrate holder used in an electroplating apparatus. The presence of such unwanted deposits is harmful to electroplating processes because the deposits scavenge current that is intended to cause electroplating on a substrate. When such current scavenging occurs, the electroplating results on the substrates are poor. For instance, features positioned near the edge of a substrate are likely to plate to an insufficient thickness. Further, where such current scavenging is great, the overall thickness of the material plated on the substrate may be too thin. As such, there is a need to detect when such unwanted deposits are present, such that plating under these poor conditions may be avoided. This detection will help preserve costly wafers.
    Type: Grant
    Filed: February 12, 2014
    Date of Patent: August 29, 2017
    Assignee: Novellus Systems, Inc.
    Inventors: Steven T. Mayer, Haiying Fu, Thomas Anand Ponnuswamy, Bryan L. Buckalew
  • Publication number: 20170148627
    Abstract: Disclosed are pre-wetting apparatus designs and methods for cleaning solid contaminants from substrates prior to through resist deposition of metal. In some embodiments, a pre-wetting apparatus includes a process chamber having a substrate holder, and at least one nozzle located directly above the wafer substrate and configured to deliver pre-wetting liquid (e.g., degassed deionized water) onto the substrate at a grazing angle of between about 5 and 45 degrees. In some embodiments the nozzle is a fan nozzle configured to deliver the liquid to the center of the substrate, such that the liquid first impacts the substrate in the vicinity of the center and then flows over the center of the substrate. In some embodiments the substrate is rotated unidirectionally or bidirectionally during pre-wetting with multiple accelerations and decelerations, which facilitate removal of contaminants.
    Type: Application
    Filed: February 3, 2017
    Publication date: May 25, 2017
    Inventors: Lee Peng Chua, Bryan L. Buckalew, Thomas Anand Ponnuswamy, Brian Paul Blackman, Chad Michael Hosack, Steven T. Mayer
  • Patent number: 9613833
    Abstract: Disclosed are pre-wetting apparatus designs and methods for cleaning solid contaminants from substrates prior to through resist deposition of metal. In some embodiments, a pre-wetting apparatus includes a process chamber having a substrate holder, and at least one nozzle located directly above the wafer substrate and configured to deliver pre-wetting liquid (e.g., degassed deionized water) onto the substrate at a grazing angle of between about 5 and 45 degrees. In some embodiments the nozzle is a fan nozzle configured to deliver the liquid to the center of the substrate, such that the liquid first impacts the substrate in the vicinity of the center and then flows over the center of the substrate. In some embodiments the substrate is rotated unidirectionally or bidirectionally during pre-wetting with multiple accelerations and decelerations, which facilitate removal of contaminants.
    Type: Grant
    Filed: February 18, 2014
    Date of Patent: April 4, 2017
    Assignee: Novellus Systems, Inc.
    Inventors: Lee Peng Chua, Bryan L. Buckalew, Thomas Anand Ponnuswamy, Brian Blackman, Chad Michael Hosack, Steven T. Mayer
  • Publication number: 20150299882
    Abstract: Disclosed herein are grain refiner releasing devices for releasing a grain refiner compound into an electrolyte solution as it is flowed to a cathode chamber during an electroplating operation. In some embodiments, the devices may include a housing for flowing an electrolyte solution having a fluidic inlet and a fluidic outlet, a particle filter located within the housing configured to remove particles from the electrolyte solution as it flows within the housing from the fluidic inlet to the fluidic outlet, and a grain refiner holder located within the housing for holding the grain refiner compound and for contacting the grain refiner compound with the electrolyte solution as the electrolyte solution flows within the housing from the fluidic inlet to the fluidic outlet. Also disclosed herein are nickel electroplating systems including such grain refiner releasing devices and nickel electroplating methods employing grain refiner compounds.
    Type: Application
    Filed: April 18, 2014
    Publication date: October 22, 2015
    Inventors: Bryan L. Buckalew, Thomas Anand Ponnuswamy
  • Publication number: 20140230855
    Abstract: The embodiments herein relate to methods and apparatus for detecting whether unwanted metallic deposits are present on a bottom of a substrate holder used in an electroplating apparatus. The presence of such unwanted deposits is harmful to electroplating processes because the deposits scavenge current that is intended to cause electroplating on a substrate. When such current scavenging occurs, the electroplating results on the substrates are poor. For instance, features positioned near the edge of a substrate are likely to plate to an insufficient thickness. Further, where such current scavenging is great, the overall thickness of the material plated on the substrate may be too thin. As such, there is a need to detect when such unwanted deposits are present, such that plating under these poor conditions may be avoided. This detection will help preserve costly wafers.
    Type: Application
    Filed: February 12, 2014
    Publication date: August 21, 2014
    Inventors: Steven T. Mayer, Haiying Fu, Thomas Anand Ponnuswamy, Bryan L. Buckalew
  • Publication number: 20140230860
    Abstract: Disclosed are pre-wetting apparatus designs and methods for cleaning solid contaminants from substrates prior to through resist deposition of metal. In some embodiments, a pre-wetting apparatus includes a process chamber having a substrate holder, and at least one nozzle located directly above the wafer substrate and configured to deliver pre-wetting liquid (e.g., degassed deionized water) onto the substrate at a grazing angle of between about 5 and 45 degrees. In some embodiments the nozzle is a fan nozzle configured to deliver the liquid to the center of the substrate, such that the liquid first impacts the substrate in the vicinity of the center and then flows over the center of the substrate. In some embodiments the substrate is rotated unidirectionally or bidirectionally during pre-wetting with multiple accelerations and decelerations, which facilitate removal of contaminants.
    Type: Application
    Filed: February 18, 2014
    Publication date: August 21, 2014
    Applicant: Novellus Systems, Inc.
    Inventors: Lee Peng Chua, Bryan L. Buckalew, Thomas Anand Ponnuswamy, Brian Blackman, Chad Michael Hosack, Steven T. Mayer
  • Publication number: 20080149489
    Abstract: A holder-wafer conjugate, including a wafer in a wafer holder, is tilted so that the planar wafer surface makes a small angle with a plane parallel to the liquid surface of a liquid bath. Then, the holder-wafer conjugate is moved downward and a leading edge of the holder-wafer conjugate makes initial contact with the liquid surface of a liquid bath at a slow piercing speed to minimize generation of shock waves and bubbles. After a small portion of the holder-wafer conjugate is immersed in the liquid bath at a first pause location, the downward movement is stopped for a first pause time. After the first pause time, downward movement of the holder-wafer conjugate is resumed at a faster post-piercing speed until the wafer is fully immersed.
    Type: Application
    Filed: August 11, 2004
    Publication date: June 26, 2008
    Applicant: Novellus Systems, Inc.
    Inventors: Seshasayee Varadarajan, Brian Prentice Knight, Thomas Anand Ponnuswamy, Robert Charles Rash, David Alan Strayer, Stephen C. Schlegel
  • Patent number: 6773571
    Abstract: The present invention pertains to methods and apparatus for electroplating a substantially uniform layer of a metal onto a work piece having a seed layer thereon. The total current of a plating cell is distributed among a plurality of anodes in the plating cell in order to tailor the current distribution in the plating electrolyte to compensate for resistance and voltage variation across a work piece due to the seed layer. Focusing elements are used to create “virtual anodes” in proximity to the plating surface of the work piece to further control the current distribution in the electrolyte during plating.
    Type: Grant
    Filed: May 22, 2002
    Date of Patent: August 10, 2004
    Assignee: Novellus Systems, Inc.
    Inventors: Steven T. Mayer, Evan E. Patton, Brian Paul Blackman, Jonathan D. Reid, Thomas Anand Ponnuswamy, Harold D. Perry