Patents by Inventor Sandeep Krishnan

Sandeep Krishnan 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: 20150211148
    Abstract: A wafer carrier for use in a chemical vapor deposition (CVD) system includes a plurality of wafer retention pockets, each having a peripheral wall surface surrounding a floor surface and defining a periphery of that wafer retention pocket. Each wafer retention pocket has a periphery with a shape defined by at least a first arc having a first radius of curvature situated around a first arc center and a second arc having a second radius of curvature situated around a second arc center. The second arc is different from the first arc, either by its radius of curvature, arc center, or both.
    Type: Application
    Filed: January 26, 2015
    Publication date: July 30, 2015
    Inventors: Sandeep Krishnan, Lukas Urban
  • Publication number: 20140360430
    Abstract: A wafer carrier assembly for use in a system for growing epitaxial layers on one or more wafers by chemical vapor deposition (CVD), the wafer carrier assembly includes a wafer carrier body formed symmetrically about a central axis, and including a generally planar top surface that is situated perpendicularly to the central axis and a planar bottom surface that is parallel to the top surface. At least one wafer retention pocket is recessed in the wafer carrier body from the top surface. Each of the at least one wafer retention pocket includes a floor surface and a peripheral wall surface that surrounds the floor surface and defines a periphery of that wafer retention pocket. At least one thermal control feature includes an interior cavity or void formed in the wafer carrier body and is defined by interior surfaces of the wafer carrier body.
    Type: Application
    Filed: June 5, 2014
    Publication date: December 11, 2014
    Inventors: Eric Armour, Sandeep Krishnan, Alex Zhang, Bojan Mitrovic, Alexander Gurary
  • Patent number: 8888360
    Abstract: A method of in-situ pyrometer calibration for a wafer treatment reactor such as a chemical vapor deposition reactor desirably includes the steps of positioning a calibrating pyrometer at a first calibrating position and heating the reactor until the reactor reaches a pyrometer calibration temperature. The method desirably further includes rotating the support element about the rotational axis, and while the support element is rotating about the rotational axis, obtaining first operating temperature measurements from a first operating pyrometer installed at a first operating position, and obtaining first calibrating temperature measurements from the calibration pyrometer. Both the calibrating pyrometer and the first operating pyrometer desirably are adapted to receive radiation from a first portion of a wafer support element at a first radial distance from a rotational axis of the wafer support element.
    Type: Grant
    Filed: December 20, 2011
    Date of Patent: November 18, 2014
    Assignee: Veeco Instruments Inc.
    Inventors: Alexander I. Gurary, Vadim Boguslavskiy, Sandeep Krishnan, Matthew King
  • Publication number: 20140261187
    Abstract: A wafer carrier and methods of making the same for use in a system for growing epitaxial layers on one or more wafers by chemical vapor deposition. The wafer carrier includes wafer retention pockets recessed in its body. A thermally-insulating spacer is situated at least partially in the at least one wafer retention pocket and arranged to maintain a spacing between the peripheral wall surface and the wafer, the spacer being constructed from a material having a thermal conductivity less than a thermal conductivity of the wafer carrier such that the spacer limits heat conduction from portions of the wafer carrier body to the wafer. The wafer carrier further includes a spacer retention feature that engages with the spacer and includes a surface oriented to prevent centrifugal movement of the spacer when subjected to rotation about the central axis.
    Type: Application
    Filed: March 15, 2013
    Publication date: September 18, 2014
    Inventors: Sandeep Krishnan, Wiliam E. Quinn, Jeffery S. Montgomery, Joshua Mangum, Lukas Urban, Alexander Gurary
  • Publication number: 20130276704
    Abstract: A wafer carrier for use in a system for growing epitaxial layers on one or more wafers by chemical vapor deposition. The wafer carrier includes wafer retention pockets recessed in its body. Each pocket includes a floor surface and a peripheral wall surface surrounding the floor surface and defining a periphery of that pocket. Each pocket has a center situated along a corresponding wafer carrier radial axis. In each of the pockets, a set of bumpers is positioned primarily at a distal portion of the wafer retention pocket opposite the central axis so as to maintain a gap of at least a predefined size between the peripheral wall surface at the distal portion and an edge of a wafer to be placed in the wafer retention pocket.
    Type: Application
    Filed: April 18, 2012
    Publication date: October 24, 2013
    Inventors: Sandeep Krishnan, Jeffrey Scott Montgomery, Lukas Urban, Alexander I. Gurary, Yuliy Rashkovsky
  • Publication number: 20130252404
    Abstract: A structure for a chemical vapor deposition reactor desirably includes a reaction chamber having an interior, a spindle mounted in the reaction chamber, and a wafer carrier releasably mounted onto the spindle for rotation therewith. The spindle desirably has a shaft extending along a vertical rotational axis and a key projecting outwardly from the shaft. The wafer carrier preferably has a body defining oppositely-facing top and bottom surfaces and at least one wafer-holding feature configured so that a wafer can be held therein with a surface of the wafer exposed at the top surface of the body. The wafer carrier desirably further has a recess extending into the body from the bottom surface of the body and a keyway projecting outwardly from a periphery of the recess along a first transverse axis. The shaft preferably is engaged in the recess and the key preferably is engaged into the keyway.
    Type: Application
    Filed: March 20, 2012
    Publication date: September 26, 2013
    Applicant: VEECO INSTRUMENTS INC.
    Inventors: Sandeep Krishnan, Keng Moy, Alexander I. Gurary, Matthew King, Vadim Boguslavskiy, Steven Krommenhoek
  • Publication number: 20130065403
    Abstract: A wafer carrier used in wafer treatments such as chemical vapor deposition has pockets for holding the wafers and support surfaces for supporting the wafers above the floors of the pockets. The carrier is provided with thermal control features such as trenches which form thermal barriers having lower thermal conductivity than surrounding portions of the carrier. These thermal control features promote a more uniform temperature distribution across the wafer surfaces and across the carrier top surface.
    Type: Application
    Filed: November 9, 2012
    Publication date: March 14, 2013
    Inventors: Ajit Paranjpe, Boris Volf, Eric A. Armour, Sandeep Krishnan, Guanghua Wei, Lukas Urban
  • Publication number: 20120170609
    Abstract: A method of in-situ pyrometer calibration for a wafer treatment reactor such as a chemical vapor deposition reactor desirably includes the steps of positioning a calibrating pyrometer at a first calibrating position and heating the reactor until the reactor reaches a pyrometer calibration temperature. The method desirably further includes rotating the support element about the rotational axis, and while the support element is rotating about the rotational axis, obtaining first operating temperature measurements from a first operating pyrometer installed at a first operating position, and obtaining first calibrating temperature measurements from the calibration pyrometer. Both the calibrating pyrometer and the first operating pyrometer desirably are adapted to receive radiation from a first portion of a wafer support element at a first radial distance from a rotational axis of the wafer support element.
    Type: Application
    Filed: December 20, 2011
    Publication date: July 5, 2012
    Applicant: VEECO INSTRUMENTS INC.
    Inventors: Alexander I. Gurary, Vadim Boguslavskiy, Sandeep Krishnan, Matthew King
  • Publication number: 20120112103
    Abstract: A seal assembly for an electric component includes a generally cylindrical plug, a first O-ring seal and a second O-ring seal. The plug includes a sidewall extending between first and second end walls. An annular groove circumscribes the sidewall. A first O-ring seal is disposed in the annular groove. A first through-bore extends between the first end wall and the second end wall. A first counter-bore circumscribes the first through-bore in the first end wall. A second O-ring seal is disposed within the first counter-bore.
    Type: Application
    Filed: November 9, 2010
    Publication date: May 10, 2012
    Applicant: HAMILTON SUNDSTRAND CORPORATION
    Inventor: Sandeep Krishnan
  • Patent number: 8141435
    Abstract: A flow metering device includes a flow tube, a motor for positioning the flow tube, an outlet nozzle in fluid communication with the flow tube, and an inlet nozzle in fluid communication with the flow tube. The outlet nozzle has an outlet pressure tap and the inlet nozzle has an inlet pressure tap. The inlet nozzle, the flow tube, and the outlet nozzle define a flow path that has a plurality of recirculation zones. At least one of the inlet pressure tap and the outlet pressure tap opens within one of the recirculation zones.
    Type: Grant
    Filed: August 3, 2009
    Date of Patent: March 27, 2012
    Assignee: Precision Engine Controls Corporation
    Inventors: Sandeep Krishnan, Mark Robert Huebscher
  • Publication number: 20110029258
    Abstract: A flow metering device includes a flow tube, a motor for positioning the flow tube, an outlet nozzle in fluid communication with the flow tube, and an inlet nozzle in fluid communication with the flow tube. The outlet nozzle has an outlet pressure tap and the inlet nozzle has an inlet pressure tap. The inlet nozzle, the flow tube, and the outlet nozzle define a flow path that has a plurality of recirculation zones. At least one of the inlet pressure tap and the outlet pressure tap opens within one of the recirculation zones.
    Type: Application
    Filed: August 3, 2009
    Publication date: February 3, 2011
    Applicant: PRECISION ENGINE CONTROLS CORPORATION
    Inventors: Sandeep Krishnan, Mark Robert Huebscher
  • Patent number: D686582
    Type: Grant
    Filed: March 20, 2012
    Date of Patent: July 23, 2013
    Assignee: Veeco Instruments Inc.
    Inventors: Sandeep Krishnan, Keng Moy
  • Patent number: D687790
    Type: Grant
    Filed: March 20, 2012
    Date of Patent: August 13, 2013
    Assignee: Veeco Instruments Inc.
    Inventors: Sandeep Krishnan, Keng Moy, Alexander I. Gurary, Matthew King, Vadim Boguslavskiy, Steven Krommenhoek
  • Patent number: D687791
    Type: Grant
    Filed: March 20, 2012
    Date of Patent: August 13, 2013
    Assignee: Veeco Instruments Inc.
    Inventors: Sandeep Krishnan, Keng Moy, Alexander I. Gurary, Matthew King, Vadim Boguslavskiy, Steven Krommenhoek
  • Patent number: D711332
    Type: Grant
    Filed: March 20, 2012
    Date of Patent: August 19, 2014
    Assignee: Veeco Instruments Inc.
    Inventors: Sandeep Krishnan, Keng Moy, Alexander I. Gurary, Matthew King, Vadim Boguslavskiy, Steven Krommenhoek
  • Patent number: D712852
    Type: Grant
    Filed: March 20, 2012
    Date of Patent: September 9, 2014
    Assignee: Veeco Instruments Inc.
    Inventors: Sandeep Krishnan, Keng Moy, Alexander I. Gurary, Matthew King, Vadim Boguslavskiy, Steven Krommenhoek
  • Patent number: D726133
    Type: Grant
    Filed: March 20, 2012
    Date of Patent: April 7, 2015
    Assignee: Veeco Instruments Inc.
    Inventors: Sandeep Krishnan, Keng Moy, Alexander I. Gurary, Matthew King, Vadim Boguslavskiy, Steven Krommenhoek
  • Patent number: D744967
    Type: Grant
    Filed: August 11, 2014
    Date of Patent: December 8, 2015
    Assignee: Veeco Instruments Inc.
    Inventors: Sandeep Krishnan, Keng Moy, Alexander I. Gurary, Matthew King, Vadim Boguslavskiy, Steven Krommenhoek
  • Patent number: D748591
    Type: Grant
    Filed: January 14, 2015
    Date of Patent: February 2, 2016
    Assignee: Veeco Instruments Inc.
    Inventors: Sandeep Krishnan, Keng Moy, Alexander I. Gurary, Matthew King, Vadim Boguslavskiy, Steven Krommenhoek