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).
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Patent number: 11702749Abstract: 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: GrantFiled: December 2, 2019Date of Patent: July 18, 2023Assignee: BOARD OF TRUSTEES OF MICHIGAN STATE UNIVERSITYInventors: Jes Asmussen, Jing Lu, Yajun Gu, Shreya Nad
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Publication number: 20200216960Abstract: 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: ApplicationFiled: December 2, 2019Publication date: July 9, 2020Inventors: Jes Asmussen, Jing Lu, Yajun Gu, Shreya Nad
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Patent number: 10494719Abstract: 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: GrantFiled: May 22, 2015Date of Patent: December 3, 2019Assignee: BOARD OF TRUSTEES OF MICHIGAN STATE UNIVERSITYInventors: Jes Asmussen, Jing Lu, Yajun Gu, Shreya Nad
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Patent number: 9890457Abstract: 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: GrantFiled: May 11, 2012Date of Patent: February 13, 2018Assignee: BOARD OF TRUSTEES OF MICHIGAN STATE UNIVERSITYInventors: Jes Asmussen, Yajun Gu, Timothy A. Grotjohn
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Publication number: 20170183778Abstract: 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: ApplicationFiled: May 22, 2015Publication date: June 29, 2017Inventors: Jes Asmussen, Jing Lu, Yajun Gu, Shreya Nad
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Patent number: 9139909Abstract: 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: GrantFiled: October 22, 2012Date of Patent: September 22, 2015Assignees: BOARD OF TRUSTEES OF MICHIGAN STATE UNIVERSITY, Fraunhofer USAInventors: Jes Asmussen, Timothy Grotjohn, Donnie K. Reinhard, Thomas Schuelke, M. Kagan Yaran, Kadek W. Hemawan, Michael Becker, David King, Yajun Gu, Jing Lu
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Publication number: 20140220261Abstract: 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: ApplicationFiled: May 11, 2012Publication date: August 7, 2014Applicant: BOARD OF TRUSTEES OF MICHIGAN STATE UNIVERSITYInventors: Jes Asmussen, Yajun Gu, Timothy A. Grotjohn
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Patent number: 8668962Abstract: 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: GrantFiled: October 22, 2012Date of Patent: March 11, 2014Assignees: Board of Trustees of Michigan State University, Fraunhofer USAInventors: Jes Asmussen, Timothy Grotjohn, Donnie K. Reinhard, Thomas Schuelke, M. Kagan Yaran, Kadek W. Hemawan, Michael Becker, David King, Yajun Gu, Jing Lu
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Patent number: 8316797Abstract: 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: GrantFiled: June 16, 2009Date of Patent: November 27, 2012Assignee: Board of Trustees of Michigan State University Fraunhofer USAInventors: Jes Asmussen, Timothy Grotjohn, Donnie K. Reinhard, Thomas Schuelke, M. Kagan Yaran, Kadek W. Hemawan, Michael Becker, David King, Yajun Gu, Jing Lu
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Publication number: 20100034984Abstract: 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: ApplicationFiled: June 16, 2009Publication date: February 11, 2010Applicants: Board of Trustees of Michigan State University, Fraunhofer USAInventors: Jes Asmussen, Timothy Grotjohn, Donnie K. Reinhard, Thomas Schuelke, M. Kagan Yaran, Kadek W. Hemawan, Michael Becker, David King, Yajun Gu, Jing Lu