Patents by Inventor Andrew D. Koehler
Andrew D. Koehler 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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Publication number: 20240097064Abstract: A light controlled semiconductor switch (LCSS), method of making, and method of using are provided. In embodiments, a vertical LCSS includes: a semiconductor body including a photoactive layer of gallium nitride (GaN) doped with carbon; a first electrode in contact with a first surface of the semiconductor body, the first electrode defining an area through which light energy from at least one light source can impinge on the first surface; and a second electrode in contact with a second surface of the semiconductor body opposed to the first surface, wherein the vertical LCSS is configured to switch from a non-conductive off-state to a conductive on-state when the light energy impinging on the semiconductor body is sufficient to raise electrons within the photoactive layer into a conduction band of the photoactive layer.Type: ApplicationFiled: September 8, 2023Publication date: March 21, 2024Inventors: Andrew D. Koehler, Travis J. Anderson, Geoffrey M. Foster, Karl D. Hobart, Francis J. Kub, Michael A. Mastro
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Patent number: 11634834Abstract: A method for growing polycrystalline diamond films having engineered grain growth and microstructure. Grain growth of a polycrystalline diamond film on a substrate is manipulated by growing the diamond on a nanopatterned substrate having features on the order of the initial grain size of the diamond film. By growing the diamond on such nanopatterned substrates, the crystal texture of a polycrystalline diamond film can be engineered to favor the preferred <110> orientation texture, which in turn enhances the thermal conductivity of the diamond film.Type: GrantFiled: August 24, 2021Date of Patent: April 25, 2023Assignee: The Government of the United States of America, as represented by the Secretary of the NavyInventors: Karl D. Hobart, Tatyana I. Feygelson, Marko J. Tadjer, Travis J. Anderson, Andrew D. Koehler, Samuel Graham, Jr., Mark Goorsky, Zhe Cheng, Luke Yates, Tingyu Bai, Yekan Wang
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Publication number: 20230030549Abstract: A hybrid edge termination structure and method of forming the same. The hybrid edge termination structure in accordance with the invention is based on a junction termination extension (JTE) architecture, but includes an additional Layer of guard ring (GR) structures to further implement the implantation of dopants into the structure. The hybrid edge termination structure of the invention has a three-Layer structure, with a top Layer and a bottom Layer each having a constant dopant concentration in the lateral direction, and a middle Layer consisting of a plurality of spatially defined alternating regions that exhibit the electrical properties of either the top or bottom layer. By including the second layer, a discretized varying charge profile can be obtained that approximates the varying charge profile obtained using tapered edge termination but with easier manufacturing and lower cost.Type: ApplicationFiled: July 28, 2022Publication date: February 2, 2023Applicant: The Government of the United States of America, as represented by the Secretary of the NavyInventors: Travis J. Anderson, Mona A. Ebrish, Andrew D. Koehler, Alan G. Jacobs, Matthew A. Porter, Karl D. Hobart, Prakash Pandey, Tolen Michael Nelson, Daniel G. Georgiev, Raghav Khanna, Michael Robert Hontz
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Patent number: 11342420Abstract: Current conducting devices and methods for their formation are disclosed. Described are vertical current devices that include a substrate, an n-type material layer, a plurality of p-type gates, and a source. The n-type material layer disposed on the substrate and includes a current channel. A plurality of p-type gates are disposed on opposite sides of the current channel. A source is disposed on a distal side of the current channel with respect to the substrate. The n-type material layer comprises beta-gallium oxide.Type: GrantFiled: September 15, 2020Date of Patent: May 24, 2022Assignee: The Government of the United States of America, as represented by the Secretary of the NavyInventors: Francis J. Kub, Travis J. Anderson, Marko J. Tadjer, Andrew D. Koehler, Karl D. Hobart
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Publication number: 20210381127Abstract: A method for growing polycrystalline diamond films having engineered grain growth and microstructure. Grain growth of a polycrystalline diamond film on a substrate is manipulated by growing the diamond on a nanopatterned substrate having features on the order of the initial grain size of the diamond film. By growing the diamond on such nanopatterned substrates, the crystal texture of a polycrystalline diamond film can be engineered to favor the preferred <110> orientation texture, which in turn enhances the thermal conductivity of the diamond film.Type: ApplicationFiled: August 24, 2021Publication date: December 9, 2021Applicant: The Government of the United States of America, as represented by the Secretary of the NavyInventors: Karl D. Hobart, Tatyana I. Feygelson, Marko J. Tadjer, Travis J. Anderson, Andrew D. Koehler, Samuel Graham, JR., Mark Goorsky, Zhe Cheng, Luke Yates, Tingyu Bai, Yekan Wang
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Patent number: 11131039Abstract: A method for growing polycrystalline diamond films having engineered grain growth and microstructure. Grain growth of a polycrystalline diamond film on a substrate is manipulated by growing the diamond on a nanopatterned substrate having features on the order of the initial grain size of the diamond film. By growing the diamond on such nanopatterned substrates, the crystal texture of a polycrystalline diamond film can be engineered to favor the preferred <110> orientation texture, which in turn enhances the thermal conductivity of the diamond film.Type: GrantFiled: May 23, 2019Date of Patent: September 28, 2021Assignee: The Government of the United States of America, as represented by the Secretary of the NavyInventors: Karl D. Hobart, Tatyana I. Feygelson, Marko J. Tadjer, Travis J. Anderson, Andrew D. Koehler, Samuel Graham, Jr., Mark Goorsky, Zhe Cheng, Luke Yates, Tingyu Bai, Yekan Wang
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Publication number: 20210005721Abstract: Current conducting devices and methods for their formation are disclosed. Described are vertical current devices that include a substrate, an n-type material layer, a plurality of p-type gates, and a source. The n-type material layer disposed on the substrate and includes a current channel. A plurality of p-type gates are disposed on opposite sides of the current channel. A source is disposed on a distal side of the current channel with respect to the substrate. The n-type material layer comprises beta-gallium oxide.Type: ApplicationFiled: September 15, 2020Publication date: January 7, 2021Inventors: Francis J. Kub, Travis J. Anderson, Marko J. Tadjer, Andrew D. Koehler, Karl D. Hobart
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Patent number: 10777644Abstract: Current conducting devices and methods for their formation are disclosed. Described are vertical current devices that include a substrate, an n-type material layer, a plurality of p-type gates, and a source. The n-type material layer disposed on the substrate and includes a current channel. A plurality of p-type gates are disposed on opposite sides of the current channel. A source is disposed on a distal side of the current channel with respect to the substrate. The n-type material layer comprises beta-gallium oxide.Type: GrantFiled: April 27, 2018Date of Patent: September 15, 2020Assignee: The Government of the United States of America, as represented by the Secretary of the NavyInventors: Francis J. Kub, Travis J. Anderson, Marko J. Tadjer, Andrew D. Koehler, Karl D. Hobart
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Publication number: 20190360117Abstract: A method for growing polycrystalline diamond films having engineered grain growth and microstructure. Grain growth of a polycrystalline diamond film on a substrate is manipulated by growing the diamond on a nanopatterned substrate having features on the order of the initial grain size of the diamond film. By growing the diamond on such nanopatterned substrates, the crystal texture of a polycrystalline diamond film can be engineered to favor the preferred <110> orientation texture, which in turn enhances the thermal conductivity of the diamond film.Type: ApplicationFiled: May 23, 2019Publication date: November 28, 2019Applicant: The Government of the United States of America, as represented by the Secretary of the NavyInventors: Karl D. Hobart, Tatyana I. Feygelson, Marko J. Tadjer, Travis J. Anderson, Andrew D. Koehler, Sam Graham, JR., Mark Goorsky, Zhe Cheng, Luke Yates, Tingyu Bai, Yekan Wang
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Publication number: 20190305157Abstract: An extreme ultraviolet (EUV) photodetector is formed by providing a substrate having a first doping type of material; forming a photodetector body layer having the first doping type of material over the substrate, wherein the photodetector body layer includes a carrier collection region and a potential barrier maximum level; and forming a carrier collection material layer over the photodetector body layer. The carrier collection region includes a region between the potential barrier maximum level and the carrier collection material layer. The potential barrier maximum level includes a height within the photodetector body layer that prevents photogenerated carriers created at a depth deeper than the potential barrier maximum level from transporting to the carrier collection region and the carrier collection material layer.Type: ApplicationFiled: April 2, 2018Publication date: October 3, 2019Inventors: Francis J. Kub, Travis J. Anderson, Karl D. Hobart, Andrew D. Koehler
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Patent number: 10424643Abstract: A device structure and method for improving thermal management in highly scaled, high power electronic and optoelectronic devices such as GaN FET and AlGaN/GaN HEMT devices by implementing diamond air bridges into such devices to remove waste heat. The diamond air bridge can be formed from a polycrystalline diamond material layer which can be grown on the surface of a dielectric material layer, on the surface of a III-nitride material, or on the surface of a diamond polycrystalline nucleation layer, and may be optimized to have a high thermal conductivity at the growth interface with the underlying material.Type: GrantFiled: April 23, 2019Date of Patent: September 24, 2019Assignee: The Government of the United States of America, as represented by the Secretary of the NavyInventors: Karl D. Hobart, Andrew D. Koehler, Francis J. Kub, Travis J. Anderson, Tatyana I. Feygelson, Marko J. Tadjer, Lunet E. Luna
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Publication number: 20190252501Abstract: A device structure and method for improving thermal management in highly scaled, high power electronic and optoelectronic devices such as GaN FET and AlGaN/GaN HEMT devices by implementing diamond air bridges into such devices to remove waste heat. The diamond air bridge can be formed from a polycrystalline diamond material layer which can be grown on the surface of a dielectric material layer, on the surface of a III-nitride material, or on the surface of a diamond polycrystalline nucleation layer, and may be optimized to have a high thermal conductivity at the growth interface with the underlying material.Type: ApplicationFiled: April 23, 2019Publication date: August 15, 2019Inventors: Karl D. Hobart, Andrew D. Koehler, Francis J. Kub, Travis J. Anderson, Tatyana I. Feygelson, Marko J. Tadjer, Lunet E. Luna
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Patent number: 10312175Abstract: A device structure and method for improving thermal management in highly scaled, high power electronic and optoelectronic devices such as GaN FET and AlGaN/GaN HEMT devices by implementing diamond air bridges into such devices to remove waste heat. The diamond air bridge can be formed from a polycrystalline diamond material layer which can be grown on the surface of a dielectric material layer, on the surface of a III-nitride material, or on the surface of a diamond polycrystalline nucleation layer, and may be optimized to have a high thermal conductivity at the growth interface with the underlying material.Type: GrantFiled: April 5, 2018Date of Patent: June 4, 2019Assignee: The United States of America, as represented by the Secretary of the NavyInventors: Karl D. Hobart, Andrew D. Koehler, Francis J. Kub, Travis J. Anderson, Tatyana I. Feygelson, Marko J. Tadjer, Lunet E. Luna
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Publication number: 20190157181Abstract: A device structure and method for improving thermal management in highly scaled, high power electronic and optoelectronic devices such as GaN FET and AlGaN/GaN HEMT devices by implementing diamond air bridges into such devices to remove waste heat. The diamond air bridge can be formed from a polycrystalline diamond material layer which can be grown on the surface of a dielectric material layer, on the surface of a III-nitride material, or on the surface of a diamond polycrystalline nucleation layer, and may be optimized to have a high thermal conductivity at the growth interface with the underlying material.Type: ApplicationFiled: April 5, 2018Publication date: May 23, 2019Applicant: The Government of the United States of America, as represented by the Secretary of the NavyInventors: Karl D. Hobart, Andrew D. Koehler, Francis J. Kub, Travis J. Anderson, Tatyana I. Feygelson, Marko J. Tadjer, Lunet E. Luna
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Patent number: 10229839Abstract: An method of annealing by: providing a substrate having a III-nitride, sapphire, silicon, diamond, gallium arsenide, or silicon carbide surface; depositing a layer of a transition metal nitride directly on the surface; and annealing the substrate at at least 900° C. in an oxygen-free environment. An article having: a substrate having a III-nitride, sapphire, silicon, diamond, gallium arsenide, or silicon carbide surface; and a layer of a transition metal nitride directly on the surface.Type: GrantFiled: May 1, 2017Date of Patent: March 12, 2019Assignee: The United States of America, as Represented by the Secretary of the NavyInventors: Travis J. Anderson, Boris N. Feygelson, Andrew D. Koehler, Karl D. Hobart, Francis J. Kub, Jordan Greenlee
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Patent number: 10158009Abstract: A method of making a graphene base transistor with reduced collector area comprising forming an electron injection region, forming an electron collection region, and forming a base region wherein the base region comprises one or more sheets of graphene and wherein the base region is intermediate the electron injection region and the electron collection region and forms electrical interfaces therewith.Type: GrantFiled: January 18, 2017Date of Patent: December 18, 2018Assignee: The United States of America, as represented by the Secretary of the NavyInventors: Francis J. Kub, Travis J. Anderson, Andrew D. Koehler
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Publication number: 20180315820Abstract: Current conducting devices and methods for their formation are disclosed. Described are vertical current devices that include a substrate, an n-type material layer, a plurality of p-type gates, and a source. The n-type material layer disposed on the substrate and includes a current channel. A plurality of p-type gates are disposed on opposite sides of the current channel. A source is disposed on a distal side of the current channel with respect to the substrate. The n-type material layer comprises beta-gallium oxide.Type: ApplicationFiled: April 27, 2018Publication date: November 1, 2018Inventors: Francis J. Kub, Travis J. Anderson, Marko J. Tadjer, Andrew D. Koehler, Karl D. Hobart
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Patent number: 10002958Abstract: Systems and method are provided for depositing metal on GaN transistors after gate formation using a metal nitride Schottky gate. Embodiments of the present disclosure use a “diamond last” process using thermally stable metal nitride gate electrodes to enable thicker heat spreading films and facilitate process integration. In an embodiment, the “diamond last” process with high thermal conductivity diamond is enabled by the integration of thermally stable metal-nitride gate electrodes.Type: GrantFiled: June 8, 2017Date of Patent: June 19, 2018Assignee: The United States of America, as represented by the Secretary of the NavyInventors: Francis J. Kub, Travis J. Anderson, Virginia D. Wheeler, Andrew D. Koehler, Karl D. Hobart
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Patent number: 9991354Abstract: Systems and methods are provided that enable the production of semiconductor devices having a metal nitride layer in direct contact with a semiconductor layer to form a Schottky diode, such as a TiN gate on an AlGaN/GaN high electron mobility transistor (HEMT). Metal nitrides offer exceptional thermal stability and a lower diffusion coefficient. Technology enabled by embodiments of the present disclosure improves the reliability of GaN-based microwave power transistors.Type: GrantFiled: May 16, 2017Date of Patent: June 5, 2018Assignee: The United States of America, as represented by the Secretary of the NavyInventors: Travis J. Anderson, Virginia D. Wheeler, David Shahin, Andrew D. Koehler, Karl D. Hobart, Francis J. Kub, Marko J. Tadjer
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Patent number: 9960266Abstract: Passivated AlGaN/GaN HEMTs having no plasma damage to the AlGaN surface and methods for making the same. In a first embodiment, a thin HF SiN barrier layer is deposited on the AlGaN surface after formation of the gate. A thick HF/LF SiN layer is then deposited, the thin HF SiN layer and the thick HF/LF Sin layer comprising bi-layer SiN passivation on the HEMT. In a second embodiment, a first thin HF SiN barrier layer is deposited on the AlGaN surface before formation of the gate and is annealed. Following annealing of the first SiN layer, the gate is formed, and a second HF SiN barrier layer is deposited, followed by a thick HF/LF SiN layer, the three SiN layers comprising tri-layer SiN passivation on the HEMT.Type: GrantFiled: May 11, 2017Date of Patent: May 1, 2018Assignee: The United States of America, as represented by the Secretary of the NavyInventors: Marko J. Tadjer, Andrew D. Koehler, Travis J. Anderson, Karl D. Hobart