Patents by Inventor Valentin N. Todorow

Valentin N. Todorow 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: 20080179009
    Abstract: A reactor is provided for removing polymer from a backside of a workpiece. The reactor includes a vacuum chamber having a ceiling, a floor and a cylindrical side wall. A workpiece support apparatus within the chamber is configured to support a workpiece thereon so that the workpiece has its front side facing the ceiling. The support apparatus leaves at least an annular periphery of the backside of the workpiece exposed. A confinement member defines a narrow gap with the outer edge of the workpiece, the narrow gap being on the order of about 1% of the workpiece diameter, the narrow gap corresponding to a boundary dividing the chamber between an upper process zone and a lower process zone. A vacuum pump is coupled to the lower process zone.
    Type: Application
    Filed: March 14, 2007
    Publication date: July 31, 2008
    Inventors: KENNETH S. COLLINS, Hiroji Hanawa, Andrew Nguyen, Ajit Balakrishna, David Palagashvili, James P. Cruse, Jennifer Y. Sun, Valentin N. Todorow, Shahid Rauf, Kartik Ramaswamy, Gerhard M. Schneider, Imad Yousif, Martin Jeffrey Salinas
  • Publication number: 20080179287
    Abstract: A process is provided for removing polymer from a backside of a workpiece. The process includes supporting the workpiece on the backside in a vacuum chamber while leaving a peripheral annular portion of the backside exposed. Gas flow is confined at the edge of the workpiece within a gap at the edge of the workpiece, the gap configured to be on the order of about 1% of the diameter of the chamber, the gap defining a boundary between an upper process zone containing the front side and a lower process zone containing the backside. The process further includes evacuating the lower process zone, generating a plasma in an external chamber from a polymer etch precursor gas, and introducing a by-product from the plasma into the lower process zone. The process further includes pumping a purge gas into the upper process zone to remove polymer etch species from the upper process zone.
    Type: Application
    Filed: March 14, 2007
    Publication date: July 31, 2008
    Inventors: Kenneth S. Collins, Hirojii Hanawa, Andrew Nguyen, Ajit Balakrishna, David Palagashvili, James P. Cruse, Jennifer Y. Sun, Valentin N. Todorow, Shahid Rauf, Kartik Ramaswamy, Gerhard M. Schneider, Imad Yousif, Martin Jeffrey Salinas
  • Publication number: 20080178913
    Abstract: A process is provided for removing polymer from a backside of a workpiece. The process includes supporting the workpiece on the backside in a vacuum chamber while leaving at least a peripheral annular portion of the backside exposed. The process further includes confining gas flow at the edge of the workpiece within a gap at the edge of the workpiece on the order of about 1% of the diameter of the chamber, the gap defining a boundary between an upper process zone containing the wafer front side and a lower process zone containing the wafer backside. The process also includes providing a polymer etch precursor gas underneath the backside edge of the workpiece and applying RF power to a region underlying the backside edge of the workpiece to generate a first plasma of polymer etch species concentrated in an annular ring concentric with and underneath the backside edge of the workpiece.
    Type: Application
    Filed: March 14, 2007
    Publication date: July 31, 2008
    Inventors: KENNETH S. COLLINS, Hiroji Hanawa, Andrew Nguyen, Ajit Balakrishna, David Palagashvili, James P. Cruse, Jennifer Y. Sun, Valentin N. Todorow, Shahid Rauf, Kartik Ramaswamy, Gerhard M. Schneider, Imad Yousif, Martin Jeffrey Salinas
  • Publication number: 20080179290
    Abstract: A workpiece is supported on the backside in a vacuum chamber while leaving at least a peripheral annular portion of a backside of the workpiece exposed. The process first increases the temperature of the workpiece starting at a temperature below about 200 degrees C. The edge of the workpiece is confined so as to establish a gap at the edge on the order of about 1% of the diameter of the chamber, the gap corresponding to a boundary between an upper process zone containing the front side and a lower process zone containing the backside. Before the workpiece temperature exceeds about 200 degrees C., backside polymer is removed using a first plasma containing polymer etch species in the lower process zone. After the workpiece temperature reaches about 300 degrees C., photoresist is stripped from the workpiece front side using by-products of a second plasma containing a photoresist strip species in the upper process zone.
    Type: Application
    Filed: March 14, 2007
    Publication date: July 31, 2008
    Inventors: Kenneth S. Collins, Hiroji Hanawa, Andrew Nguyen, Ajit Balakrishna, David Palagashvili, James P. Cruse, Jennifer Y. Sun, Valentin N. Todorow, Shahid Rauf, Kartik Ramaswamy, Gerhard M. Schneider, Imad Yousif, Martin Jeffrey Salinas
  • Publication number: 20080179288
    Abstract: A process is provided for removing polymer from a backside of a workpiece. The process includes supporting the workpiece on the backside in a vacuum chamber while leaving a peripheral annular portion of the backside exposed. The process further includes confining gas flow at the edge of the workpiece within a gap at the edge of the workpiece on the order of about 1% of the diameter of the chamber, the gap defining a boundary between an upper process zone containing the front side and a lower process zone containing the backside. A first plasma is generated in a lower external chamber from a polymer etch precursor gas, and an etchant by-product is introduced from the first plasma into the lower process zone. A second plasma is generated in an upper external plasma chamber from a precursor gas of a scavenger of the etchant by-product, and scavenger species are introduced from the second plasma into the upper process zone.
    Type: Application
    Filed: March 14, 2007
    Publication date: July 31, 2008
    Inventors: KENNETH S. COLLINS, Hiroji Hanawa, Andrew Nguyen, Ajit Balakrishna, David Palagashvili, James P. Cruse, Jennifer Y. Sun, Valentin N. Todorow, Shahid Rauf, Kartik Ramaswamy, Gerhard M. Schneider, Imad Yousif, Martin Jeffrey Salinas
  • Publication number: 20080178805
    Abstract: A plasma reactor is provided for processing a workpiece such as a semiconductor wafer or a dielectric mask. The reactor chamber has a ceiling, a side wall and a workpiece support pedestal inside the chamber and facing the ceiling along an axis of symmetry and defining a chamber volume between the pedestal and the ceiling. An RF plasma source power applicator is provided at the ceiling. An in-situ electrode body inside the chamber lies divides the chamber into upper and lower chamber regions. The in-situ electrode comprises plural flow-through passages extending parallel to the axis and having different opening sizes, the passages being radially distributed by opening size in accordance with a desired radial distribution of gas flow resistance through the in-situ electrode body.
    Type: Application
    Filed: November 28, 2007
    Publication date: July 31, 2008
    Inventors: Alexander M. Paterson, John P. Holland, Theodoros Panagopoulos, Edward P. Hammond, Brian K. Hatcher, Valentin N. Todorow, Dan Katz
  • Publication number: 20080179007
    Abstract: A reactor is provided for removing polymer from a backside of a workpiece. The reactor includes a vacuum chamber having a ceiling, a floor and a cylindrical side wall. The reactor further includes workpiece support apparatus within the chamber configured for a workpiece to be placed thereon with its front side facing the ceiling. The support apparatus is configured to leave at least an annular periphery of the backside of the workpiece exposed. A confinement member defines a narrow gap with an outer edge of the workpiece, the narrow gap being on the order of about 1% of the workpiece diameter, the narrow gap corresponding to a boundary dividing the chamber between an upper process zone and a lower process zone, the reactor further comprising a vacuum pump coupled to the lower process zone.
    Type: Application
    Filed: March 14, 2007
    Publication date: July 31, 2008
    Inventors: KENNETH S. COLLINS, Hiroji Hanawa, Andrew Nguyen, Ajit Balakrishna, David Palagashvili, James P. Cruse, Jennifer Y. Sun, Valentin N. Todorow, Shahid Rauf, Kartik Ramaswamy, Gerhard M. Schneider, Imad Yousif, Martin Jeffrey Salinas
  • Publication number: 20080149592
    Abstract: Line edge smoothness in a hardmask etch process is improved by widening the chamber pressure process window by applying VHF power and increasing the chamber pressure to near the maximum value of the widened process window.
    Type: Application
    Filed: November 20, 2007
    Publication date: June 26, 2008
    Inventors: Rodolfo P. Belen, Edward P. Hammond, Brian K. Hatcher, Dan Katz, Theodoros Panagopoulos, Alexander M. Paterson, Valentin N. Todorow
  • Patent number: 7264688
    Abstract: A plasma reactor includes a toroidal plasma source having an RF power applicator, and RF generator being coupled to the RF power applicator. The reactor further includes a capacitively coupled plasma source power applicator or electrode at the ceiling or the workpiece support, a VHF power generator being coupled to the capacitively coupled source power applicator, a plasma bias power applicator or electrode in the workpiece support and an RF bias power generator coupled to the plasma bias power applicator. A controller adjusts the relative amounts of power simultaneously coupled to plasma in the chamber and conduit by the toroidal plasma source and by the capacitively coupled plasma source power applicator.
    Type: Grant
    Filed: April 24, 2006
    Date of Patent: September 4, 2007
    Assignee: Applied Materials, Inc.
    Inventors: Alexander Paterson, Valentin N. Todorow, Theodoros Panagopoulos, Brian K. Hatcher, Dan Katz, Edward P. Hammond, IV, John P. Holland, Alexander Matyushkin
  • Patent number: 6893533
    Abstract: The invention in one embodiment is realized in a plasma reactor for processing a semiconductor workpiece. The reactor includes a vacuum chamber having a side wall and a ceiling, a workpiece support pedestal within the chamber and generally facing the ceiling, a gas inlet capable of supplying a process gas into the chamber and a solenoidal interleaved parallel conductor coil antenna overlying the ceiling and including a first plurality conductors wound about an axis of symmetry generally perpendicular to the ceiling in respective concentric helical solenoids of at least nearly uniform lateral displacements from the axis of symmetry, each helical solenoid being offset from the other helical solenoids in a direction parallel to the axis of symmetry. An RF plasma source power supply is connected across each of the plural conductors.
    Type: Grant
    Filed: October 29, 2003
    Date of Patent: May 17, 2005
    Inventors: John Holland, Valentin N. Todorow, Michael Barnes
  • Publication number: 20040083971
    Abstract: The invention in one embodiment is realized in a plasma reactor for processing a semiconductor workpiece. The reactor includes a vacuum chamber having a side wall and a ceiling, a workpiece support pedestal within the chamber and generally facing the ceiling, a gas inlet capable of supplying a process gas into the chamber and a solenoidal interleaved parallel conductor coil antenna overlying the ceiling and including a first plurality conductors wound about an axis of symmetry generally perpendicular to the ceiling in respective concentric helical solenoids of at least nearly uniform lateral displacements from the axis of symmetry, each helical solenoid being offset from the other helical solenoids in a direction parallel to the axis of symmetry. An RF plasma source power supply is connected across each of the plural conductors.
    Type: Application
    Filed: October 29, 2003
    Publication date: May 6, 2004
    Applicant: Applied Materials, Inc.
    Inventors: John Holland, Valentin N. Todorow, Michael Barnes
  • Patent number: 6727655
    Abstract: A method and apparatus is disclosed to monitor and/or control the electrical states at a workpiece disposed in a plasma chamber that is in electrical communication with an RF signal source over a defined signal path. The method includes ascertaining an impedance of the signal path, sensing electrical characteristics of the RF power at the RF signal source and obtaining values of the electrical states at the workpiece. To provide a more accurate model of the electrical states at the workpiece, the modeling includes information concerning the impedance introduced by the signal path. This technique may be employed to provide feedback control of the RF generator, so that the electrical states may be dynamically adjusted be within predefined, or desired, parameters.
    Type: Grant
    Filed: October 26, 2001
    Date of Patent: April 27, 2004
    Inventors: Jon McChesney, Alex Paterson, Valentin N. Todorow, John Holland, Michael Barnes
  • Patent number: 6694915
    Abstract: The invention in one embodiment is realized in a plasma reactor for processing a semiconductor workpiece. The reactor includes a vacuum chamber having a side wall and a ceiling, a workpiece support pedestal within the chamber and generally facing the ceiling, a gas inlet capable of supplying a process gas into the chamber and a solenoidal interleaved parallel conductor coil antenna overlying the ceiling and including a first plurality conductors wound about an axis of symmetry generally perpendicular to the ceiling in respective concentric helical solenoids of at least nearly uniform lateral displacements from the axis of symmetry, each helical solenoid being offset from the other helical solenoids in a direction parallel to the axis of symmetry. A RF plasma source power supply is connected across each of the plural conductors.
    Type: Grant
    Filed: July 6, 2000
    Date of Patent: February 24, 2004
    Assignee: Applied Materials, Inc
    Inventors: John Holland, Valentin N. Todorow, Michael Barnes
  • Patent number: 6685798
    Abstract: The invention in one embodiment is realized in a plasma reactor for processing a semiconductor workpiece. The reactor includes a vacuum chamber having a side wall and a ceiling, a workpiece support pedestal within the chamber and generally facing the ceiling, a gas inlet capable of supplying a process gas into the chamber and a solenoidal interleaved parallel conductor coil antenna overlying the ceiling and including a first plurality conductors wound about an axis of symmetry generally perpendicular to the ceiling in respective concentric helical solenoids of at least nearly uniform lateral displacements from the axis of symmetry, each helical solenoid being offset from the other helical solenoids in a direction parallel to the axis of symmetry. An RF plasma source power supply is connected across each of the plural conductors.
    Type: Grant
    Filed: July 6, 2000
    Date of Patent: February 3, 2004
    Assignee: Applied Materials, Inc
    Inventors: John Holland, Valentin N. Todorow, Michael Barnes
  • Publication number: 20030082835
    Abstract: A method and apparatus is disclosed to monitor and/or control the electrical states at a workpiece disposed in a plasma chamber that is in electrical communication with an RF signal source over a defined signal path. The method includes ascertaining an impedance of the signal path, sensing electrical characteristics of the RF power at the RF signal source and obtaining values of the electrical states at the workpiece. To provide a more accurate model of the electrical states at the workpiece, the modeling includes information concerning the impedance introduced by the signal path. This technique may be employed to provide feedback control of the RF generator, so that the electrical states may be dynamically adjusted be within predefined, or desired, parameters.
    Type: Application
    Filed: October 26, 2001
    Publication date: May 1, 2003
    Applicant: APPLIED MATERIALS,INC.
    Inventors: Jon McChesney, Alex Paterson, Valentin N. Todorow, John Holland, Michael Barnes
  • Patent number: 6472822
    Abstract: A system and method for overcoming the above-described problems relating to the delivery of pulsed RF power to a plasma processing chamber. The power reflected from the chamber is reduced using one or more of the following techniques: (1) varying the RF frequency within a pulse period; (2) ramping up the pulse heights at the leading edge of the pulse train; (3) simultaneously transmitting a relatively low CW signal along with the pulsed signal; and (4) rapidly switching the shunt capacitance within a local matching network within a pulse period. The amount of power delivered to the plasma by the pulses is measured by way of a time-averaging mechanism coupled to a directional coupler connected to the transmission line. The time-averaging mechanism may comprise circuitry to measure temperatures of loads attached to the directional coupler, or analog integrating circuitry attached to the directional coupler, or digital integrating circuitry attached to the directional coupler.
    Type: Grant
    Filed: April 28, 2000
    Date of Patent: October 29, 2002
    Assignee: Applied Materials, Inc.
    Inventors: Jin-Yuan Chen, John P. Holland, Arthur H. Sato, Valentin N. Todorow
  • Patent number: 6462481
    Abstract: The invention is realized in a plasma reactor for processing a semiconductor workpiece. The reactor includes a vacuum chamber having a side wall and a ceiling, a workpiece support pedestal within the chamber and generally facing the ceiling, a gas inlet capable of supplying a process gas into the chamber and a solenoidal interleaved parallel conductor coil antenna overlying the ceiling and including a first plurality conductors wound about an axis of symmetry generally perpendicular to the ceiling in respective concentric helical solenoids of at least nearly uniform lateral displacements from the axis of symmetry, each helical solenoid being offset from the other helical solenoids in a direction parallel to the axis of symmetry. An RF plasma source power supply is connected across each of the plural conductors.
    Type: Grant
    Filed: July 6, 2000
    Date of Patent: October 8, 2002
    Assignee: Applied Materials Inc.
    Inventors: John Holland, Valentin N. Todorow, Michael Barnes
  • Patent number: 6414648
    Abstract: The invention in one embodiment is realized in a plasma reactor for processing a semiconductor workpiece. The reactor includes a vacuum chamber having a side wall and a ceiling, a workpiece support pedestal within the chamber and generally facing the ceiling, a gas inlet capable of supplying a process gas into the chamber and a solenoidal interleaved parallel conductor coil antenna overlying the ceiling and including a first plurality conductors wound about an axis of symmetry generally perpendicular to the ceiling in respective concentric helical solenoids of at least nearly uniform lateral displacements from the axis of symmetry, each helical solenoid being offset from the other helical solenoids in a direction parallel to the axis of symmetry. A RF plasma source power supply is connected across each of the plural conductors.
    Type: Grant
    Filed: July 6, 2000
    Date of Patent: July 2, 2002
    Assignee: Applied Materials, Inc.
    Inventors: John Holland, Valentin N. Todorow, Michael Barnes
  • Patent number: 6409933
    Abstract: The invention is realized in a plasma reactor for processing a semiconductor workpiece. The reactor includes a vacuum chamber having a side wall and a ceiling, a workpiece support pedestal within the chamber and generally facing the ceiling, a gas inlet capable of supplying a process gas into the chamber and a solenoidal interleaved parallel conductor coil antenna overlying the ceiling and including a first plurality conductors wound about an axis of symmetry generally perpendicular to the ceiling in respective concentric helical solenoids of at least nearly uniform lateral displacements from the axis of symmetry, each helical solenoid being offset from the other helical solenoids in a direction parallel to the axis of symmetry. An RF plasma source power supply is connected across each of the plural conductors.
    Type: Grant
    Filed: July 6, 2000
    Date of Patent: June 25, 2002
    Assignee: Applied Materials, Inc.
    Inventors: John Holland, Valentin N. Todorow, Michael Barnes