Patents by Inventor Karl D. Hobart
Karl D. Hobart 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: 9305858Abstract: An array of through-silicon vias (TSVs) are formed in a silicone substrate. The vias can be tapered such that the diameter of the via at the surface of the substrate is larger than the diameter of the via at its bottom, with the diameter varying continuously along its depth. After the via is formed, it is seeded with a thin layer of nanocrystalline diamond (NCD) particles, and a NCD film is grown on the bottom and along the sidewalls of the via. The presence of the diamond-filled vias provides improved thermal management to semiconductor devices formed on the silicon substrate.Type: GrantFiled: August 7, 2015Date of Patent: April 5, 2016Assignee: The United States of America, as represented by the Secretary of the NavyInventors: Karl D. Hobart, Marko J. Tadjer, Tatyana I. Feygelson, Bradford B. Pate, Travis J. Anderson
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Patent number: 9275998Abstract: An inverted P-channel III-nitride field effect transistor with hole carriers in the channel comprising a gallium-polar III-Nitride grown epitaxially on a substrate, a barrier, a two-dimensional hole gas in the barrier layer material at the heterointerface of the first material, and wherein the gallium-polar III-Nitride material comprises III-Nitride epitaxial material layers grown in such a manner that when GaN is epitaxially grown the top surface of the epitaxial layer is gallium-polar. A method of making a P-channel III-nitride field effect transistor with hole carriers in the channel comprising selecting a face of a substrate so that the gallium-polar (0001) face is the dominant face for growth of III-Nitride epitaxial layer growth material, growing a GaN epitaxial layer, doping, growing a barrier, etching, forming a contact, performing device isolation, defining a gate opening, defining gate metal, making a contact window, and depositing and defining a thick metal.Type: GrantFiled: April 29, 2014Date of Patent: March 1, 2016Assignee: The United States of America, as represented by the Secretary of the NavyInventors: Francis J. Kub, Travis J. Anderson, Andrew D. Koehler, Karl D. Hobart
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Patent number: 9246305Abstract: A light-emitting device having one or more diamond layers integrated therein and methods for forming a light-emitting device with integrated diamond layers. The diamond is grown either directly on the semiconductor material comprising the light-emitting structure, on a nucleation layer deposited on the semiconductor material, or on a dielectric layer deposited on the semiconductor material before growth of the diamond layer. The device can include a trench or thermal shunt formed in the substrate on the backside of the device, or can include a heat sink to provide additional thermal management.Type: GrantFiled: March 20, 2015Date of Patent: January 26, 2016Assignee: The United States of America, as represented by the Secretary of the NavyInventors: Francis J. Kub, Travis J. Anderson, Karl D. Hobart
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Publication number: 20150348866Abstract: An array of through-silicon vias (TSVs) are formed in a silicone substrate. The vias can be tapered such that the diameter of the via at the surface of the substrate is larger than the diameter of the via at its bottom, with the diameter varying continuously along its depth. After the via is formed, it is seeded with a thin layer of nanocrystalline diamond (NCD) particles, and a NCD film is grown on the bottom and along the sidewalls of the via. The presence of the diamond-filled vias provides improved thermal management to semiconductor devices formed on the silicon substrate.Type: ApplicationFiled: August 7, 2015Publication date: December 3, 2015Applicant: The Government of the United States of America, as represented by the Secretary of the NavyInventors: Karl D. Hobart, Marko J. Tadjer, Tatyana I. Feygelson, Bradford B. Pate, Travis J. Anderson
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Patent number: 9196614Abstract: An inverted P-channel III-nitride field effect transistor with hole carriers in the channel comprising a gallium-polar III-Nitride barrier material, a second material layer, a two-dimensional hole gas in the second layer, and wherein the gallium-polar material comprises one or more III-Nitride epitaxial material layers grown such that when GaN is epitaxially grown the top surface of the epitaxial layer is gallium-polar. A method of making an inverted P-channel III-nitride field effect transistor with hole carriers in the channel comprising selecting a face or offcut orientation of a substrate so that the gallium-polar (0001) face is the dominant face, growing a nucleation layer, growing a gallium-polar epitaxial layer, doping the epitaxial layer, growing a barrier layer, etching the GaN, forming contacts, performing device isolation, defining a gate opening, depositing and defining gate metal, making a contact window, depositing and defining a thick metal.Type: GrantFiled: February 9, 2015Date of Patent: November 24, 2015Assignee: The United States of America, as represented by the Secretary of the NavyInventors: Francis J. Kub, Travis J. Anderson, Andrew D. Koehler, Karl D. Hobart
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Patent number: 9196703Abstract: A method for fabricating a semiconductor device, such as a GaN high electron mobility transistor (HEMT) device, including etching a thermal via into a back-side of a semiconductor substrate and depositing a diamond nucleation seed layer across the back-side of the substrate. The method further includes coating the diamond nucleation with a mask layer and removing mask material outside of the thermal via on the planar portions of the back-side of the substrate. The method includes removing portions of the diamond nucleation layer on the planar portions and then removing the remaining portion of the mask material in the thermal via. The method then includes depositing a bulk diamond layer within the thermal via on the remaining portion of the diamond nucleation layer so that diamond only grows in the thermal via and not on the planar portions of the substrate.Type: GrantFiled: August 20, 2014Date of Patent: November 24, 2015Assignees: Northrop Grumman Systems Corporation, The United States of America, as Represented by the Secretary of the Navy, The Regents of the University of CaliforniaInventors: Karl D. Hobart, Tatyana I. Feygelson, Eugene I. Imhoff, Travis J. Anderson, Joshua D. Caldwell, Andrew D. Koehler, Bradford B. Pate, Marko J. Tadjer, Rajinder S. Sandhu, Vincent Gambin, Gregory Lewis, Ioulia Smorchkova, Mark Goorsky, Jeff McKay
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Patent number: 9159641Abstract: An array of through-silicon vias (TSVs) are formed in a silicone substrate. The vias can be tapered such that the diameter of the via at the surface of the substrate is larger than the diameter of the via at its bottom, with the diameter varying continuously along its depth. After the via is formed, it is seeded with a thin layer of nanocrystalline diamond (NCD) particles, and a NCD film is grown on the bottom and along the sidewalls of the via. The presence of the diamond-filled vias provides improved thermal management to semiconductor devices formed on the silicon substrate.Type: GrantFiled: March 14, 2014Date of Patent: October 13, 2015Assignee: The Government of the United States of America, as represented by the Secretary of the NavyInventors: Karl D. Hobart, Marko J. Tadjer, Tatyana I. Feygelson, Bradford B. Pate, Travis J. Anderson
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Publication number: 20150221727Abstract: An inverted P-channel III-nitride field effect transistor with hole carriers in the channel comprising a gallium-polar III-Nitride grown epitaxially on a substrate, a barrier, a two-dimensional hole gas in the barrier layer material at the heterointerface of the first material, and wherein the gallium-polar III-Nitride material comprises III-Nitride epitaxial material layers grown in such a manner that when GaN is epitaxially grown the top surface of the epitaxial layer is gallium-polar. A method of making a P-channel III-nitride field effect transistor with hole carriers in the channel comprising selecting a face of a substrate so that the gallium-polar (0001) face is the dominant face for growth of III-Nitride epitaxial layer growth material, growing a GaN epitaxial layer, doping, growing a barrier, etching, forming a contact, performing device isolation, defining a gate opening, defining gate metal, making a contact window, and depositing and defining a thick metal.Type: ApplicationFiled: April 29, 2014Publication date: August 6, 2015Applicant: The Government of the United States of America, as represented by the Secretary of the NavyInventors: Francis J. Kub, Travis J. Anderson, Andrew D. Koehler, Karl D. Hobart
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Publication number: 20150221760Abstract: An inverted P-channel III-nitride field effect transistor with hole carriers in the channel comprising a gallium-polar III-Nitride first material, a barrier material layer, a two-dimensional hole gas in the barrier layer, and wherein the gallium-polar material comprises one or more III-Nitride epitaxial material layers grown such that when GaN is epitaxially grown the top surface of the epitaxial layer is gallium-polar. A method of making an inverted P-channel III-nitride field effect transistor with hole carriers in the channel comprising selecting a face or offcut orientation of a substrate so that the gallium-polar (0001) face is the dominant face, growing a nucleation layer, growing a gallium-polar epitaxial layer, doping the epitaxial layer, growing a barrier layer, etching the GaN, forming contacts, performing device isolation, defining a gate opening, depositing and defining gate metal, making a contact window, depositing and defining a thick metal.Type: ApplicationFiled: February 9, 2015Publication date: August 6, 2015Applicant: The Government of the United States of America, as represented by the Secretary of the NavyInventors: Francis J. Kub, Travis J. Anderson, Andrew D. Koehler, Karl D. Hobart
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Patent number: 9029833Abstract: Ultraviolet or Extreme Ultraviolet and/or visible detector apparatus and fabrication processes are presented, in which the detector includes a thin graphene electrode structure disposed over a semiconductor surface to provide establish a potential in the semiconductor material surface and to collect photogenerated carriers, with a first contact providing a top side or bottom side connection for the semiconductor structure and a second contact for connection to the graphene layer.Type: GrantFiled: August 28, 2014Date of Patent: May 12, 2015Assignee: The Government of the United States of America, as represented by the Secretary of the NavyInventors: Francis J. Kub, Karl D. Hobart, Travis J. Anderson
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Patent number: 9006791Abstract: A non-inverted P-channel III-nitride field effect transistor with hole carriers in the channel comprising a nitrogen-polar III-Nitride first material, a barrier material layer, a two-dimensional hole gas in the barrier layer, and wherein the nitrogen-polar III-Nitride material comprises one or more III-Nitride epitaxial material layers grown in such a manner that when GaN is epitaxially grown the top surface of the epitaxial layer is nitrogen-polar. A method of making a P-channel III-nitride field effect transistor with hole carriers in the channel comprising selecting a face or offcut orientation of a substrate so that the nitrogen-polar (001) face is the dominant face, growing a nucleation layer, growing a GaN epitaxial layer, doping the epitaxial layer, growing a barrier layer, etching the GaN, forming contacts, performing device isolation, defining a gate opening, depositing and defining gate metal, making a contact window, depositing and defining a thick metal.Type: GrantFiled: January 31, 2014Date of Patent: April 14, 2015Assignee: The Government of the United States of America, as represented by the Secretary of the NavyInventors: Francis J. Kub, Travis J. Anderson, Andrew D. Koehler, Karl D. Hobart
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Publication number: 20150060947Abstract: A field effect transistor having a diamond gate electrode and a process for forming the same. In some embodiments, the device is an AlGaN/GaN high-electron-mobility transistor (HEMT). The diamond gate electrode is formed so that it directly contacts the barrier layer. In some embodiments, the diamond gate electrode is formed from boron-doped nanocrystalline diamond (NCD), while in other embodiments, the diamond gate electrode is formed from single crystal diamond.Type: ApplicationFiled: August 28, 2014Publication date: March 5, 2015Applicant: The Government of the United States of America, as represented by the Secretary of the NavyInventors: Andrew D. Koehler, Travis J. Anderson, Marko J. Tadjer, Tatyana I. Feygelson, Karl D. Hobart
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Publication number: 20150056763Abstract: A method for fabricating a semiconductor device, such as a GaN high electron mobility transistor (HEMT) device, including etching a thermal via into a back-side of a semiconductor substrate and depositing a diamond nucleation seed layer across the back-side of the substrate. The method further includes coating the diamond nucleation with a mask layer and removing mask material outside of the thermal via on the planar portions of the back-side of the substrate. The method includes removing portions of the diamond nucleation layer on the planar portions and then removing the remaining portion of the mask material in the thermal via. The method then includes depositing a bulk diamond layer within the thermal via on the remaining portion of the diamond nucleation layer so that diamond only grows in the thermal via and not on the planar portions of the substrate.Type: ApplicationFiled: August 20, 2014Publication date: February 26, 2015Inventors: Karl D. Hobart, Tatyana I. Feygelson, Eugene A. Imhoff, Travis J. Anderson, Joshua D. Caldwell, Andrew D. Koehler, Bradford B. Pate, Marko J. Tadjer, Randijer S. Sandhu, Vincent Gambin, Gregory Lewis, Ioulia Smorchkova, Mark Goorsky, Jeff McKay
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Publication number: 20140367824Abstract: Ultraviolet or Extreme Ultraviolet and/or visible detector apparatus and fabrication processes are presented, in which the detector includes a thin graphene electrode structure disposed over a semiconductor surface to provide establish a potential in the semiconductor material surface and to collect photogenerated carriers, with a first contact providing a top side or bottom side connection for the semiconductor structure and a second contact for connection to the graphene layer.Type: ApplicationFiled: August 28, 2014Publication date: December 18, 2014Applicant: The Govemment of the United States of America, as represented by the Secretary of the NavyInventors: Francis J. Kub, Karl D. Hobart, Travis J. Anderson
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Patent number: 8900939Abstract: High electron mobility transistors and fabrication processes are presented in which a barrier material layer of uniform thickness is provided for threshold voltage control under an enhanced channel charge inducing material layer (ECCIML) in source and drain regions with the ECCIML layer removed in the gate region.Type: GrantFiled: January 28, 2014Date of Patent: December 2, 2014Assignee: The United States of America, as represented by the Secretary of the NavyInventors: Francis J. Kub, Travis Anderson, Karl D. Hobart, Michael A. Mastro, Charles R. Eddy, Jr.
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Publication number: 20140335666Abstract: Methods for forming a high-quality III-nitride passivation layer on an AlGaN/GaN HEMT. A III-nitride passivation layer is formed on the surface of an AlGaN/GaN HEMT by means of atomic layer epitaxy (ALE), either before or after deposition of a gate metal electrode on the AlGaN barrier layer. Depending on the gate metal and/or the passivation material used, the III-nitride passivation layer can be formed by ALE at temperatures between about 300° C. and about 850° C. In a specific embodiment, the III-nitride passivation layer can be an AlN layer formed by ALE at about 550° C. after deposition of a Schottky metal gate electrode. The III-nitride passivation layer can be grown so as to conformally cover the entire device, providing a hermetic seal that protects the against environmental conditions.Type: ApplicationFiled: May 8, 2014Publication date: November 13, 2014Applicant: The Government of the United States of America, as represented by the Secretary of the NavyInventors: Andrew D. Koehler, Travis J. Anderson, Karl D. Hobart, Francis J. Kub
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Patent number: 8872159Abstract: Ultraviolet or Extreme Ultraviolet and/or visible detector apparatus and fabrication processes are presented, in which the detector includes a thin graphene electrode structure disposed over a semiconductor surface to provide establish a potential in the semiconductor material surface and to collect photogenerated carriers, with a first contact providing a top side or bottom side connection for the semiconductor structure and a second contact for connection to the graphene layer.Type: GrantFiled: September 28, 2012Date of Patent: October 28, 2014Assignee: The United States of America, as represented by the Secretary of the NavyInventors: Francis J. Kub, Travis Anderson, Karl D. Hobart
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Publication number: 20140264379Abstract: A non-inverted P-channel III-nitride field effect transistor with hole carriers in the channel comprising a nitrogen-polar III-Nitride first material, a barrier material layer, a two-dimensional hole gas in the barrier layer, and wherein the nitrogen-polar III-Nitride material comprises one or more III-Nitride epitaxial material layers grown in such a manner that when GaN is epitaxially grown the top surface of the epitaxial layer is nitrogen-polar. A method of making a P-channel III-nitride field effect transistor with hole carriers in the channel comprising selecting a face or offcut orientation of a substrate so that the nitrogen-polar (001) face is the dominant face, growing a nucleation layer, growing a GaN epitaxial layer, doping the epitaxial layer, growing a barrier layer, etching the GaN, forming contacts, performing device isolation, defining a gate opening, depositing and defining gate metal, making a contact window, depositing and defining a thick metal.Type: ApplicationFiled: January 31, 2014Publication date: September 18, 2014Applicant: The Government of the United States of America, as represented by the Secretary of the NavyInventors: Francis J. Kub, Travis J. Anderson, Andrew D. Koehler, Karl D. Hobart
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Publication number: 20140264777Abstract: An array of through-silicon vias (TSVs) are formed in a silicone substrate. The vias can be tapered such that the diameter of the via at the surface of the substrate is larger than the diameter of the via at its bottom, with the diameter varying continuously along its depth. After the via is formed, it is seeded with a thin layer of nanocrystalline diamond (NCD) particles, and a NCD film is grown on the bottom and along the sidewalls of the via. The presence of the diamond-filled vias provides improved thermal management to semiconductor devices formed on the silicon substrate.Type: ApplicationFiled: March 14, 2014Publication date: September 18, 2014Applicant: The Government of the United States of America, as represented by the Secretary of the NavyInventors: Karl D. Hobart, Marko J. Tadjer, Tatyana I. Feygelson, Bradford B. Pate, Travis J. Anderson
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Patent number: 8753468Abstract: A method for reducing graphene film thickness on a donor substrate and transferring graphene films from a donor substrate to a handle substrate includes applying a bonding material to the graphene on the donor substrate, releasing the bonding material from the donor substrate thereby leaving graphene on the bonding material, applying the bonding material with graphene onto the handle substrate, and releasing the bonding material from the handle substrate thereby leaving the graphene on the handle substrate. The donor substrate may comprise SiC, metal foil or other graphene growth substrate, and the handle substrate may comprise a semiconductor or insulator crystal, semiconductor device, epitaxial layer, flexible substrate, metal film, or organic device.Type: GrantFiled: August 12, 2010Date of Patent: June 17, 2014Assignee: The United States of America, as represented by the Secretary of the NavyInventors: Joshua D. Caldwell, Karl D. Hobart, Travis Anderson, Francis J. Kub