Patents by Inventor Yajun Gu

Yajun Gu 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).

  • Patent number: 11702749
    Abstract: The disclosure relates to microwave cavity plasma reactor (MCPR) apparatus and associated tuning and process control methods that enable the microwave plasma assisted chemical vapor deposition (MPACVD) of a component such as diamond. Related methods enable the control of the microwave discharge position, size and shape, and enable efficient matching of the incident microwave power into the reactor prior to and during component deposition. Pre-deposition tuning processes provide a well matched reactor exhibiting a high plasma reactor coupling efficiency over a wide range of operating conditions, thus allowing operational input parameters to be modified during deposition while simultaneously maintaining the reactor in a well-matched state.
    Type: Grant
    Filed: December 2, 2019
    Date of Patent: July 18, 2023
    Assignee: BOARD OF TRUSTEES OF MICHIGAN STATE UNIVERSITY
    Inventors: Jes Asmussen, Jing Lu, Yajun Gu, Shreya Nad
  • Publication number: 20200216960
    Abstract: The disclosure relates to microwave cavity plasma reactor (MCPR) apparatus and associated tuning and process control methods that enable the microwave plasma assisted chemical vapor deposition (MPACVD) of a component such as diamond. Related methods enable the control of the microwave discharge position, size and shape, and enable efficient matching of the incident microwave power into the reactor prior to and during component deposition. Pre-deposition tuning processes provide a well matched reactor exhibiting a high plasma reactor coupling efficiency over a wide range of operating conditions, thus allowing operational input parameters to be modified during deposition while simultaneously maintaining the reactor in a well-matched state.
    Type: Application
    Filed: December 2, 2019
    Publication date: July 9, 2020
    Inventors: Jes Asmussen, Jing Lu, Yajun Gu, Shreya Nad
  • Patent number: 10494719
    Abstract: The disclosure relates to microwave cavity plasma reactor (MCPR) apparatus and associated tuning and process control methods that enable the microwave plasma assisted chemical vapor deposition (MPACVD) of a component such as diamond. Related methods enable the control of the microwave discharge position, size and shape, and enable efficient matching of the incident microwave power into the reactor prior to and during component deposition. Pre-deposition tuning processes provide a well matched reactor exhibiting a high plasma reactor coupling efficiency over a wide range of operating conditions, thus allowing operational input parameters to be modified during deposition while simultaneously maintaining the reactor in a well-matched state.
    Type: Grant
    Filed: May 22, 2015
    Date of Patent: December 3, 2019
    Assignee: BOARD OF TRUSTEES OF MICHIGAN STATE UNIVERSITY
    Inventors: Jes Asmussen, Jing Lu, Yajun Gu, Shreya Nad
  • Patent number: 9890457
    Abstract: Microwave plasma assisted reactors, for example chemical vapor deposition (MPCVD) reactors, are disclosed. The disclosed reactors operate at high pressures (>180-320 Torr) and high power densities (>150 W/cm3), and thereby enable high deposition rate CVD processes that rapidly deposit materials. In particular, reactor design examples are described that, when operating in the 180-320 Torr pressure regime, rapidly CVD synthesize high quality polycrystalline (PCD) and single crystal diamond (SCD). The improved reactors include a radial contraction in the vicinity of the plasma chamber (and optionally a combined expansion in the vicinity of the electromagnetic wave source, followed by the contraction) in the main microwave chamber as electromagnetic energy propagates from an electromagnetic wave source to a plasma/deposition chamber.
    Type: Grant
    Filed: May 11, 2012
    Date of Patent: February 13, 2018
    Assignee: BOARD OF TRUSTEES OF MICHIGAN STATE UNIVERSITY
    Inventors: Jes Asmussen, Yajun Gu, Timothy A. Grotjohn
  • Publication number: 20170183778
    Abstract: The disclosure relates to microwave cavity plasma reactor (MCPR) apparatus and associated tuning and process control methods that enable the microwave plasma assisted chemical vapor deposition (MPACVD) of a component such as diamond. Related methods enable the control of the microwave discharge position, size and shape, and enable efficient matching of the incident microwave power into the reactor prior to and during component deposition. Pre-deposition tuning processes provide a well matched reactor exhibiting a high plasma reactor coupling efficiency over a wide range of operating conditions, thus allowing operational input parameters to be modified during deposition while simultaneously maintaining the reactor in a well-matched state.
    Type: Application
    Filed: May 22, 2015
    Publication date: June 29, 2017
    Inventors: Jes Asmussen, Jing Lu, Yajun Gu, Shreya Nad
  • Patent number: 9139909
    Abstract: New and improved microwave plasma assisted reactors, for example chemical vapor deposition (MPCVD) reactors, are disclosed. The disclosed microwave plasma assisted reactors operate at pressures ranging from about 10 Torr to about 760 Torr. The disclosed microwave plasma assisted reactors include a movable lower sliding short and/or a reduced diameter conductive stage in a coaxial cavity of a plasma chamber. For a particular application, the lower sliding short position and/or the conductive stage diameter can be variably selected such that, relative to conventional reactors, the reactors can be tuned to operate over larger substrate areas, operate at higher pressures, and discharge absorbed power densities with increased diamond synthesis rates (carats per hour) and increased deposition uniformity.
    Type: Grant
    Filed: October 22, 2012
    Date of Patent: September 22, 2015
    Assignees: BOARD OF TRUSTEES OF MICHIGAN STATE UNIVERSITY, Fraunhofer USA
    Inventors: Jes Asmussen, Timothy Grotjohn, Donnie K. Reinhard, Thomas Schuelke, M. Kagan Yaran, Kadek W. Hemawan, Michael Becker, David King, Yajun Gu, Jing Lu
  • Publication number: 20140220261
    Abstract: Microwave plasma assisted reactors, for example chemical vapor deposition (MPCVD) reactors, are disclosed. The disclosed reactors operate at high pressures (>180-320 Torr) and high power densities (>150 W/cm3), and thereby enable high deposition rate CVD processes that rapidly deposit materials. In particular, reactor design examples are described that, when operating in the 180-320 Torr pressure regime, rapidly CVD synthesize high quality polycrystalline (PCD) and single crystal diamond (SCD). The improved reactors include a radial contraction in the vicinity of the plasma chamber (and optionally a combined expansion in the vicinity of the electromagnetic wave source, followed by the contraction) in the main microwave chamber as electromagnetic energy propagates from an electromagnetic wave source to a plasma/deposition chamber.
    Type: Application
    Filed: May 11, 2012
    Publication date: August 7, 2014
    Applicant: BOARD OF TRUSTEES OF MICHIGAN STATE UNIVERSITY
    Inventors: Jes Asmussen, Yajun Gu, Timothy A. Grotjohn
  • Patent number: 8668962
    Abstract: New and improved microwave plasma assisted reactors, for example chemical vapor deposition (MPCVD) reactors, are disclosed. The disclosed microwave plasma assisted reactors operate at pressures ranging from about 10 Torr to about 760 Torr. The disclosed microwave plasma assisted reactors include a movable lower sliding short and/or a reduced diameter conductive stage in a coaxial cavity of a plasma chamber. For a particular application, the lower sliding short position and/or the conductive stage diameter can be variably selected such that, relative to conventional reactors, the reactors can be tuned to operate over larger substrate areas, operate at higher pressures, and discharge absorbed power densities with increased diamond synthesis rates (carats per hour) and increased deposition uniformity.
    Type: Grant
    Filed: October 22, 2012
    Date of Patent: March 11, 2014
    Assignees: Board of Trustees of Michigan State University, Fraunhofer USA
    Inventors: Jes Asmussen, Timothy Grotjohn, Donnie K. Reinhard, Thomas Schuelke, M. Kagan Yaran, Kadek W. Hemawan, Michael Becker, David King, Yajun Gu, Jing Lu
  • Patent number: 8316797
    Abstract: New and improved microwave plasma assisted reactors, for example chemical vapor deposition (MPCVD) reactors, are disclosed. The disclosed microwave plasma assisted reactors operate at pressures ranging from about 10 Torr to about 760 Torr. The disclosed microwave plasma assisted reactors include a movable lower sliding short and/or a reduced diameter conductive stage in a coaxial cavity of a plasma chamber. For a particular application, the lower sliding short position and/or the conductive stage diameter can be variably selected such that, relative to conventional reactors, the reactors can be tuned to operate over larger substrate areas, operate at higher pressures, and discharge absorbed power densities with increased diamond synthesis rates (carats per hour) and increased deposition uniformity.
    Type: Grant
    Filed: June 16, 2009
    Date of Patent: November 27, 2012
    Assignee: Board of Trustees of Michigan State University Fraunhofer USA
    Inventors: Jes Asmussen, Timothy Grotjohn, Donnie K. Reinhard, Thomas Schuelke, M. Kagan Yaran, Kadek W. Hemawan, Michael Becker, David King, Yajun Gu, Jing Lu
  • Publication number: 20100034984
    Abstract: New and improved microwave plasma assisted reactors, for example chemical vapor deposition (MPCVD) reactors, are disclosed. The disclosed microwave plasma assisted reactors operate at pressures ranging from about 10 Torr to about 760 Torr. The disclosed microwave plasma assisted reactors include a movable lower sliding short and/or a reduced diameter conductive stage in a coaxial cavity of a plasma chamber. For a particular application, the lower sliding short position and/or the conductive stage diameter can be variably selected such that, relative to conventional reactors, the reactors can be tuned to operate over larger substrate areas, operate at higher pressures, and discharge absorbed power densities with increased diamond synthesis rates (carats per hour) and increased deposition uniformity.
    Type: Application
    Filed: June 16, 2009
    Publication date: February 11, 2010
    Applicants: Board of Trustees of Michigan State University, Fraunhofer USA
    Inventors: Jes Asmussen, Timothy Grotjohn, Donnie K. Reinhard, Thomas Schuelke, M. Kagan Yaran, Kadek W. Hemawan, Michael Becker, David King, Yajun Gu, Jing Lu