Patents by Inventor Timothy A. Grotjohn

Timothy A. Grotjohn 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: 12098475
    Abstract: The disclosure relates to large area single crystal diamond (SCD) surfaces and substrates, and their methods of formation. Typical large area substrates can be at least about 25 mm, 50 mm, or 100 mm in diameter or square edge length, and suitable thicknesses can be about 100 ?m to 1000 ?m. The large area substrates have a high degree of crystallographic alignment. The large area substrates can be used in a variety of electronics and/or optics applications. Methods of forming the large area substrates generally include lateral and vertical growth of SCD on spaced apart and crystallographically aligned SCD seed substrates, with the individual SCD growth layers eventually merging to form a composite SCD layer of high quality and high crystallographic alignment. A diamond substrate holder can be used to crystallographically align the SCD seed substrates and reduce the effect of thermal stress on the formed SCD layers.
    Type: Grant
    Filed: May 16, 2019
    Date of Patent: September 24, 2024
    Assignees: BOARD OF TRUSTEES OF MICHIGAN STATE UNIVERSITY, Fraunhofer USA
    Inventors: Timothy A. Grotjohn, Ramon Diaz, Aaron Hardy
  • Patent number: 11897087
    Abstract: A polishing apparatus is provided. Another aspect pertains to a self-leveling polishing apparatus for smoothing diamonds. Yet another aspect of the present system uses a ball and swivel joint in a diamond polishing machine. A further aspect employs a polishing apparatus including a diamond-holder, an elongated arm using gravity to apply downward polishing pressure of the diamond workpiece against a polishing wheel, and a sweeping transmission to cause the holder to radially move across the rotating polishing wheel.
    Type: Grant
    Filed: March 9, 2022
    Date of Patent: February 13, 2024
    Assignees: Board of Trustees of Michigan State University, Fraunhofer USA
    Inventors: Aaron Hardy, Timothy A. Grotjohn, Edward K. Drown, Michael Becker
  • Patent number: 11854775
    Abstract: The disclosure relates to microwave cavity plasma reactor (MCPR) apparatus and associated optical measurement system that enable microwave plasma assisted chemical vapor deposition (MPACVD) of a component such as diamond while measuring the local surface properties of the component while being grown. Related methods include deposition of the component, measurement of the local surface properties, and/or alteration of operating conditions during deposition in response to the local surface properties. As described in more detail below, the MPCR apparatus includes one or more electrically conductive, optically transparent regions forming part of the external boundary of its microwave chamber, thus permitting external optical interrogation of internal reactor conditions during deposition while providing a desired electrical microwave chamber to maintain selected microwave excitation modes therein.
    Type: Grant
    Filed: January 16, 2020
    Date of Patent: December 26, 2023
    Assignee: BOARD OF TRUSTEES OF MICHIGAN STATE UNIVERSITY
    Inventors: Timothy A. Grotjohn, Jes Asmussen
  • Publication number: 20230286102
    Abstract: A polishing apparatus is provided. Another aspect pertains to a self-leveling polishing apparatus for smoothing diamonds. Yet another aspect of the present system uses a ball and swivel joint in a diamond polishing machine. A further aspect employs a polishing apparatus including a diamond-holder, an elongated arm using gravity to apply downward polishing pressure of the diamond workpiece against a polishing wheel, and a sweeping transmission to cause the holder to radially move across the rotating polishing wheel.
    Type: Application
    Filed: March 9, 2022
    Publication date: September 14, 2023
    Applicants: Board of Trustees of Michigan State University, Fraunhofer USA
    Inventors: Aaron HARDY, Timothy A. GROTJOHN, Edward K. DROWN, Michael BECKER
  • Publication number: 20230062860
    Abstract: A laser activated luminescence system is provided. Another aspect pertains to a system employing a plasma assisted vapor deposition reactor which creates diamond layers on a substrate, in combination with a laser system to at least photoactivate and anneal the diamond layers. Yet another aspect of the present system uses a laser to assist with placement of color centers, such as nitrogen vacancy centers, in diamond. The present method uses lasers to manufacture more than two activated nitrogen vacancy center nodes in a diamond substrate, with nanometer spatial resolution and at a predetermined depth.
    Type: Application
    Filed: October 26, 2022
    Publication date: March 2, 2023
    Applicant: Board of Trustees of Michigan State University
    Inventors: Marcos DANTUS, Timothy A. GROTJOHN
  • Patent number: 11222956
    Abstract: In some embodiments, a semiconductor structure can include: a diamond substrate having a surface conductive layer; a heavily doped region formed in the diamond substrate; and a metal contact positioned over the conductive surface layer such that a first portion of the heavily doped region is covered by the metal contact and a second portion of the heavily doped region is not covered by the metal contact.
    Type: Grant
    Filed: April 9, 2020
    Date of Patent: January 11, 2022
    Assignee: Massachusetts Institute of Technology
    Inventors: Joseph Varghese, Timothy Grotjohn, Michael Geis
  • Publication number: 20210320183
    Abstract: In some embodiments, a semiconductor structure can include: a diamond substrate having a surface conductive layer; a heavily doped region formed in the diamond substrate; and a metal contact positioned over the conductive surface layer such that a first portion of the heavily doped region is covered by the metal contact and a second portion of the heavily doped region is not covered by the metal contact.
    Type: Application
    Filed: April 9, 2020
    Publication date: October 14, 2021
    Inventors: Joseph Varghese, Timothy Grotjohn, Michael Geis
  • Publication number: 20210214856
    Abstract: The disclosure relates to large area single crystal diamond (SCD) surfaces and substrates, and their methods of formation. Typical large area substrates can be at least about 25 mm, 50 mm, or 100 mm in diameter or square edge length, and suitable thicknesses can be about 100 ?m to 1000 ?m. The large area substrates have a high degree of crystallographic alignment. The large area substrates can be used in a variety of electronics and/or optics applications. Methods of forming the large area substrates generally include lateral and vertical growth of SCD on spaced apart and crystallographically aligned SCD seed substrates, with the individual SCD growth layers eventually merging to form a composite SCD layer of high quality and high crystallographic alignment. A diamond substrate holder can be used to crystallographically align the SCD seed substrates and reduce the effect of thermal stress on the formed SCD layers.
    Type: Application
    Filed: May 16, 2019
    Publication date: July 15, 2021
    Inventors: Timothy A. Grotjohn, Ramon Diaz, Aron Hardy
  • Publication number: 20200152433
    Abstract: The disclosure relates to microwave cavity plasma reactor (MCPR) apparatus and associated optical measurement system that enable microwave plasma assisted chemical vapor deposition (MPACVD) of a component such as diamond while measuring the local surface properties of the component while being grown. Related methods include deposition of the component, measurement of the local surface properties, and/or alteration of operating conditions during deposition in response to the local surface properties. As described in more detail below, the MPCR apparatus includes one or more electrically conductive, optically transparent regions forming part of the external boundary of its microwave chamber, thus permitting external optical interrogation of internal reactor conditions during deposition while providing a desired electrical microwave chamber to maintain selected microwave excitation modes therein.
    Type: Application
    Filed: January 16, 2020
    Publication date: May 14, 2020
    Inventors: Timothy A. Grotjohn, Jes Asmussen
  • Patent number: 10541118
    Abstract: The disclosure relates to microwave cavity plasma reactor (MCPR) apparatus and associated optical measurement system that enable microwave plasma assisted chemical vapor deposition (MPACVD) of a component such as diamond while measuring the local surface properties of the component while being grown. Related methods include deposition of the component, measurement of the local surface properties, and/or alteration of operating conditions during deposition in response to the local surface properties. As described in more detail below, the MCPR apparatus includes one or more electrically conductive, optically transparent regions forming part of the external boundary of its microwave chamber, thus permitting external optical interrogation of internal reactor conditions during deposition while providing a desired electrical microwave chamber to maintain selected microwave excitation modes therein.
    Type: Grant
    Filed: March 20, 2017
    Date of Patent: January 21, 2020
    Assignee: BOARD OF TRUSTEES OF MICHIGAN STATE UNIVERSITY
    Inventors: Timothy A. Grotjohn, Jes Asmussen
  • 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: 20170271132
    Abstract: The disclosure relates to microwave cavity plasma reactor (MCPR) apparatus and associated optical measurement system that enable microwave plasma assisted chemical vapor deposition (MPACVD) of a component such as diamond while measuring the local surface properties of the component while being grown. Related methods include deposition of the component, measurement of the local surface properties, and/or alteration of operating conditions during deposition in response to the local surface properties. As described in more detail below, the MPCR apparatus includes one or more electrically conductive, optically transparent regions forming part of the external boundary of its microwave chamber, thus permitting external optical interrogation of internal reactor conditions during deposition while providing a desired electrical microwave chamber to maintain selected microwave excitation modes therein.
    Type: Application
    Filed: March 20, 2017
    Publication date: September 21, 2017
    Inventors: Timothy A. Grotjohn, Jes Asmussen
  • Patent number: 9732440
    Abstract: The present invention relates to a microwave plasma deposition process and apparatus for producing diamond, preferably as single crystal diamond (SCD). The process and apparatus enables the production of multiple layers of the diamond by the use of an extending device to increase the length and the volume of a recess in a holder containing a SCD substrate as layers of diamond are deposited. The diamond is used for abrasives, cutting tools, gems, electronic substrates, heat sinks, electrochemical electrodes, windows for high power radiation and electron beams, and detectors.
    Type: Grant
    Filed: November 1, 2016
    Date of Patent: August 15, 2017
    Assignees: BOARD OF TRUSTEES OF MICHIGAN STATE UNIVERSITY, Fraunhofer USA
    Inventors: Jes Asmussen, Timothy A. Grotjohn, Donnie K. Reinhard, Rahul Ramamurti, M. Kagan Yaran, Thomas Schuelke, Michael Becker, David King
  • Publication number: 20170114476
    Abstract: The present invention relates to a microwave plasma deposition process and apparatus for producing diamond, preferably as single crystal diamond (SCD). The process and apparatus enables the production of multiple layers of the diamond by the use of an extending device to increase the length and the volume of a recess in a holder containing a SCD substrate as layers of diamond are deposited. The diamond is used for abrasives, cutting tools, gems, electronic substrates, heat sinks, electrochemical electrodes, windows for high power radiation and electron beams, and detectors.
    Type: Application
    Filed: November 1, 2016
    Publication date: April 27, 2017
    Inventors: Jes Asmussen, Timothy A. Grotjohn, Donnie K. Reinhard, Rahul Ramamurti, M. Kagan Yaran, Thomas Schuelke, Michael Becker, David King
  • Publication number: 20170067154
    Abstract: Systems and methods are described for using microplasmas in 3D printing to deposit materials, remove materials, or modify the properties of materials deposited on a given substrate surface. The resulting microplasma-based 3D printing enables the integration of different types of materials into the same 3D printed structure that is not possible with current technology.
    Type: Application
    Filed: September 9, 2016
    Publication date: March 9, 2017
    Inventor: Timothy A. Grotjohn
  • Patent number: 9487858
    Abstract: The present invention relates to a microwave plasma deposition process and apparatus for producing diamond, preferably as single crystal diamond (SCD). The process and apparatus enables the production of multiple layers of the diamond by the use of an extending device to increase the length and the volume of a recess in a holder containing a SCD substrate as layers of diamond are deposited. The diamond is used for abrasives, cutting tools, gems, electronic substrates, heat sinks, electrochemical electrodes, windows for high power radiation and electron beams, and detectors.
    Type: Grant
    Filed: March 10, 2009
    Date of Patent: November 8, 2016
    Assignees: BOARD OF TRUSTEES OF MICHIGAN STATE UNIVERSITY, Fraunhofer USA
    Inventors: Jes Asmussen, Timothy Grotjohn, Donnie Reinhard, Rahul Ramamurti, M. Kagan Yaran, Thomas Schuelke, Michael Becker, David King
  • Patent number: 9277792
    Abstract: The disclosure relates to the inclusion of an image embedded in or on a single crystal diamond such that the image is part of the single crystal diamond structure. The disclosed methods use a combination of gemstone deposition processes and patterning processes to create single crystal gemstones with embedded color variations that can create externally visible two-dimensional or three-dimensional images in a seamless single crystal matrix without visible internal lines/interfacial boundaries. The image embedded image is differently colored from the surrounding diamond matrix. The color variation is accomplished by a change in the diamond growth conditions or treatment of the diamond.
    Type: Grant
    Filed: August 23, 2011
    Date of Patent: March 8, 2016
    Assignee: BOARD OF TRUSTEES OF MICHIGAN STATE UNIVERSITY
    Inventors: Timothy A. Grotjohn, Carolyn Randall
  • Patent number: 9166002
    Abstract: The disclosure relates to the formation of n-doped single crystal diamond (SCD). In general, a SCD substrate is preferentially anisotropically etched to provide one or more recesses in the SCD substrate, where the recesses are defined by (1 1 1) surface sidewalls resulting from the preferential anisotropic etching process. The recesses generally have a pyramidal shape. N-type doped SCD (e.g., using a phosphorous dopant) is then deposited into the preferentially anisotropically etched recesses. When the SCD substrate is a p-type diamond (e.g., using a boron dopant), the resulting structure can be used as a p-n junction, for example for use in various power electronic apparatus such as diodes, etc.
    Type: Grant
    Filed: August 31, 2011
    Date of Patent: October 20, 2015
    Assignee: BOARD OF TRUSTEES OF MICHIGAN STATE UNIVERSITY
    Inventors: Timothy A. Grotjohn, Jes Asmussen, Timothy Hogan
  • 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