Patents by Inventor Prasad N. Gadgil

Prasad N. Gadgil 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: 20100213643
    Abstract: A simple and direct methodology for synthesis of polycrystalline silicon sheets is demonstrated in our invention, where silica (SiO2) and elemental carbon (C) are reacted under RF or MW excitation. These polycrystalline silicon sheets can be directly used as feedstock/substrates for low cost photovoltaic solar cell fabrication. Other techniques, such as textured polycrystalline silicon substrate formation, in situ doping, and in situ formation of p-n junctions, are described, which make use of processing equipments and scheme setups of various embodiments of the invention.
    Type: Application
    Filed: February 25, 2010
    Publication date: August 26, 2010
    Inventors: Prasad N. Gadgil, Rajat Roychoudhury, Mushtaq Mulla, Indrajit Banerjee
  • Patent number: 7365005
    Abstract: This invention relates to process sequence by high-speed atomic layer chemical vapor processing that includes deposition for diffusion barriers in the etched features on substrate followed by gap fill and subsequent in-situ removal of the blanket films on the top by plasma enhanced vapor phase processes. The apparatus and process sequences employed in these processing scheme allows the practitioner to complete all vapor phase process sequences of diffusion barrier deposition, gap fill and planarization of copper and diffusion barrier planarization. In case of copper metallization scheme, vapor phase gap fill can be employed to replace electrochemical deposition of copper and removal of copper and the diffusion barrier by vapor phase reactions can replace chemical-mechanical-polishing. Furthermore, such a processing scheme can be employed to deposit gate level dielectric layer, shallow trench isolation and also to form first metal contact plugs with a suitable barrier at the front end of line processing.
    Type: Grant
    Filed: June 22, 2005
    Date of Patent: April 29, 2008
    Inventor: Prasad N. Gadgil
  • Publication number: 20040224504
    Abstract: An apparatus and method for plasma enhanced monolayer (PEM) processing, wherein excited species from a non-condensable gas plasma are delivered to a substrate surface during the reaction of a chemical precursor with a previously chemisorbed monolayer on the substrate surface; the excited species lower the activation energy of the monolayer formation reaction and also modulate the film properties. In preferred embodiments a process reactor has linear injectors arranged diametrically above a substrate and reactive gases are sequentially injected onto the substrate surface while it is being rotated. The reactor can be operated in pulse precursor and pulsed plasma, constant precursor and constant plasma modes, or a combination thereof.
    Type: Application
    Filed: June 9, 2004
    Publication date: November 11, 2004
    Inventor: Prasad N. Gadgil
  • Patent number: 6563092
    Abstract: Methods and an apparatus for providing a non-contact probe for accurately measuring the temperature of a substrate in a process chamber are disclosed. One exemplary apparatus is a processing chamber, which includes a heating source, where the heating source heats the substrate. Also included is a window maintained at a substantially constant temperature. The window allows only a first wavelength spectrum of energy emitted from the heating source to pass. In addition, the window isolates the heating source from an internal region of the processing chamber. A probe configured to detect a second wavelength spectrum of energy emitted directly from the substrate is included. The energy emitted directly from the substrate corresponds to a temperature of the substrate, and the temperature of the substrate is provided to the controller, which adjusts an intensity of the heating source based on a set point temperature for the substrate.
    Type: Grant
    Filed: November 28, 2001
    Date of Patent: May 13, 2003
    Assignee: Novellus Systems, Inc.
    Inventors: Krishnan Shrinivasan, Arkadiy Shimanovich, Prasad N. Gadgil
  • Patent number: 6387185
    Abstract: A processing station adaptable to standard cluster tools has a vertically-translatable pedestal having an upper wafer-support surface including a heater plate adapted to be plugged into a unique feedthrough in the pedestal. At a lower position for the pedestal wafers may be transferred to and from the processing station, and at an upper position for the pedestal the pedestal forms an annular pumping passage with a lower circular opening in a processing chamber. A removable, replaceable ring at the lower opening of the processing chamber allows process pumping speed to be tailored for different processes by replacing the ring. In some embodiments the pedestal also has a surrounding shroud defining an annular pumping passage around the pedestal. A unique two-zone heater plate is adapted to the top of the pedestal, and connects to a unique feedthrough allowing heater plates to be quickly and simply replaced.
    Type: Grant
    Filed: January 16, 2001
    Date of Patent: May 14, 2002
    Assignee: Genus, Inc.
    Inventors: Kenneth Doering, Carl J. Galewski, Prasad N. Gadgil, Thomas E. Seidel
  • Publication number: 20010011526
    Abstract: A processing station adaptable to standard cluster tools has a vertically-translatable pedestal having an upper wafer-support surface including a heater plate adapted to be plugged into a unique feedthrough in the pedestal. At a lower position for the pedestal wafers may be transferred to and from the processing station, and at an upper position for the pedestal the pedestal forms an annular pumping passage with a lower circular opening in a processing chamber. A removable, replaceable ring at the lower opening of the processing chamber allows process pumping speed to be tailored for different processes by replacing the ring. In some embodiments the pedestal also has a surrounding shroud defining an annular pumping passage around the pedestal. A unique two-zone heater plate is adapted to the top of the pedestal, and connects to a unique feedthrough allowing heater plates to be quickly and simply replaced.
    Type: Application
    Filed: January 16, 2001
    Publication date: August 9, 2001
    Inventors: Kenneth Doering, Carl J. Galewski, Prasad N. Gadgil, Thomas E. Seidel
  • Patent number: 6174377
    Abstract: A processing station adaptable to standard cluster tools has a vertically-translatable pedestal having an upper wafer-support surface including a heater plate adapted to be plugged into a unique feedthrough in the pedestal. At a lower position for the pedestal wafers may be transferred to and from the processing station, and at an upper position for the pedestal the pedestal forms an annular pumping passage with a lower circular opening in a processing chamber. A removable, replaceable ring at the lower opening of the processing chamber allows process pumping speed to be tailored for different processes by replacing the ring. In some embodiments the pedestal also has a surrounding shroud defining an annular pumping passage around the pedestal. A unique two-zone heater plate is adapted to the top of the pedestal, and connects to a unique feedthrough allowing heater plates to be quickly and simply replaced.
    Type: Grant
    Filed: January 4, 1999
    Date of Patent: January 16, 2001
    Assignee: Genus, Inc.
    Inventors: Kenneth Doering, Carl J. Galewski, Prasad N. Gadgil, Thomas E. Seidel
  • Patent number: 5879459
    Abstract: A low profile, compact atomic layer deposition reactor (LP-CAR) has a low-profile body with a substrate processing region adapted to serve a single substrate or a planar array of substrates, and a valved load and unload port for substrate loading and unloading to and from the LP-CAR. The body has an inlet adapted for injecting a gas or vapor at the first end, and an exhaust exit adapted for evacuating gas and vapor at the second end. The LP-CAR has an external height no greater than any horizontal dimension, and more preferably no more than two-thirds any horizontal dimension, facilitating a unique system architecture. An internal processing region is distinguished by having a vertical extent no greater than one fourth the horizontal extent, facilitating fast gas switching. In some embodiments one substrate at a time is processed, and in other embodiments there may be multiple substrates arranged in the processing region in a planar array.
    Type: Grant
    Filed: August 29, 1997
    Date of Patent: March 9, 1999
    Assignee: Genus, Inc.
    Inventors: Prasad N. Gadgil, Thomas E. Seidel
  • Patent number: 5284519
    Abstract: This invention relates to a novel inverted diffuser stagnation point flow reactor which can be used for vapor deposition of thin solid films on substrates. A metalorganic chemical vapor deposition reactor comprising a gas mixing chamber with gas entry ports into the mixing chamber; a substrate for deposition thereon of solid film; and a gas outlet for conveying gas away from the substrate, characterized by a capillary plug positioned at the base of an inverted diffuser between the mixing chamber and the substrate, the capillary plug serving to streamline the flow of gas to the substrate.
    Type: Grant
    Filed: May 16, 1991
    Date of Patent: February 8, 1994
    Assignee: Simon Fraser University
    Inventor: Prasad N. Gadgil