Patents by Inventor Asif Khan

Asif Khan 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: 8686396
    Abstract: An ultra-violet light-emitting device and method for fabricating an ultraviolet light emitting device, 12, (LED or an LD) with an AlInGaN multiple-quantum-well active region, 10, exhibiting stable cw-powers. The device includes a non c-plane template with an ultraviolet light-emitting structure thereon. The template includes a first buffer layer, 321, on a substrate, 100, then a second buffer layer, 421, on the first preferably with a strain-relieving layer, 302, in both buffer layers. Next there is a semiconductor layer having a first type of conductivity, 500, followed by a layer providing a quantum-well region, 600. Another semiconductor layer, 700, having a second type of conductivity is applied next. Two metal contacts, 980 and 990, are applied to this construction, one to the semiconductor layer having the first type of conductivity and the other to the semiconductor layer having the second type of conductivity, to complete the light emitting device.
    Type: Grant
    Filed: May 8, 2008
    Date of Patent: April 1, 2014
    Assignee: Nitek, Inc.
    Inventor: Asif Khan
  • Patent number: 8680551
    Abstract: A vertically conducting LED comprising, in a layered arrangement: a highly thermally conductive submount wherein the highly conductive submount has a thermal conductivity of at least 100 W/m0K; a p-type layer comprising Al1-x-yInyGax N wherein 0?x?1 and 0?y?1; a quantum well layer comprising Al1-x-yInyGaxN wherein 0?x?1 and 0?y?1; an n-type layer comprising Al1-x-yInyGaxN wherein 0?x?1 and 0?y?1; and an n-type contact layer wherein the LED has a peak emission at 200-365 nm.
    Type: Grant
    Filed: March 23, 2011
    Date of Patent: March 25, 2014
    Assignee: Nitek, Inc.
    Inventors: Vinod Adivarahan, Qhalid Fareed, Asif Khan
  • Patent number: 8652958
    Abstract: A vertical geometry light emitting diode with a strain relieved superlattice layer on a substrate comprising doped AlXInYGa1-X-YN. A first doped layer is on the strain relieved superlattice layer AlXInYGa1-X-YN and the first doped layer has a first conductivity. A multilayer quantum well is on the first doped layer comprising alternating layers quantum wells and barrier layers. The multilayer quantum well terminates with a barrier layer on each side thereof. A second doped layer is on the quantum well wherein the second doped layer comprises AlXInYGa1-X-YN and said second doped layer has a different conductivity than said first doped layer. A contact layer is on the third doped layer and the contact layer has a different conductivity than the third doped layer. A metallic contact is in a vertical geometry orientation.
    Type: Grant
    Filed: September 7, 2011
    Date of Patent: February 18, 2014
    Assignee: Nitek, Inc.
    Inventor: Asif Khan
  • Publication number: 20140025733
    Abstract: A social networking architecture comprises a plurality of nodes (persons) connected to one another by bonds reflecting common interests, the bonds having a strength, a time dimension, a geographic dimension, and an availability (e.g. ad hoc) dimension. Network members are allowed to define flexible interests (e.g. hobbies, professional skills/credentials), with the network revealing a strength of common interest between individual nodes. The temporal and geographic dimensions of the interest allow the network to connect available members having similar interest(s) in a specific location at a given time. An interface engine may allow the social network architecture to leverage relationships from pre-existing social networks and channels of communication.
    Type: Application
    Filed: July 17, 2012
    Publication date: January 23, 2014
    Applicant: SAP AG
    Inventors: Mohammad Asif Khan, Juergen Schmerder
  • Publication number: 20140015011
    Abstract: Fabrication methods of a high frequency (sub-micron gate length) operation of AlInGaN/InGaN/GaN MOS-DHFET, and the HFET device resulting from the fabrication methods, are generally disclosed. The method of forming the HFET device generally includes a novel double-recess etching and a pulsed deposition of an ultra-thin, high-quality silicon dioxide layer as the active gate-insulator. The methods of the present invention can be utilized to form any suitable field effect transistor (FET), and are particular suited for forming high electron mobility transistors (HEMT).
    Type: Application
    Filed: July 2, 2013
    Publication date: January 16, 2014
    Inventors: M. Asif Khan, Vinod Adivarahan
  • Publication number: 20130313613
    Abstract: Methods for forming a HEMT device are provided. The method includes forming an ultra-thin barrier layer on the plurality of thin film layers. A dielectric thin film layer is formed over a portion of the ultra-thin barrier layer to leave exposed areas of the ultra-thin barrier layer. A SAG S-D thin film layer is formed over the exposed areas of the ultra-thin barrier layer while leaving the dielectric thin film layer exposed. The dielectric thin film layer is then removed to expose the underlying ultra-thin barrier layer. The underlying ultra-thin barrier layer is treating with fluorine to form a treated area. A source and drain is added on the SAG S-D thin film layer, and a dielectric coating is deposited over the ultra-thin barrier layer treated with fluorine such that the dielectric coating is positioned between the source and the drain.
    Type: Application
    Filed: April 25, 2013
    Publication date: November 28, 2013
    Inventors: Asif Khan, Qhalid Fareed, Vinod Adivarahan
  • Patent number: 8563995
    Abstract: A light emitting device with a template comprising a substrate and a nested superlattice. The superlattice has Al1-x-yInyGaxN wherein 0?x?? and 0?y?1 with x increasing with distance from said substrate. An ultraviolet light-emitting structure on the template has a first layer with a first conductivity comprising Al1-x-yInyGaxN wherein ??x; a light emitting quantum well region above the first layer comprising Al1-x-yInyGaxN wherein ??x?b; and a second layer over the light emitting quantum well with a second conductivity comprising Al1-x-yInyGaxN wherein b?x. The light emitting device also has a first electrical contact in electrical connection with the first layer, a second electrical contact in electrical connection with the second layer; and the device emits ultraviolet light.
    Type: Grant
    Filed: March 27, 2009
    Date of Patent: October 22, 2013
    Assignee: Nitek, Inc.
    Inventors: Asif Khan, Qhalid Fareed
  • Publication number: 20130256631
    Abstract: Ultraviolet light emitting illuminator, and method for fabricating same, comprises an array of ultraviolet light emitting diodes and a first and second terminal. When an alternating current is applied across the first and second terminals and thus to each of the diodes, the illuminator emits ultraviolet light at a frequency corresponding to that of the alternating current. The illuminator includes a template with ultraviolet light emitting quantum wells, a first buffer layer with a first type of conductivity and a second buffer layer with a second type of conductivity, all deposited preferably over strain-relieving layer. A first and second metal contact are applied to the semiconductor layers having the first and second type of conductivity, respectively, to complete the LED. The emission spectrum ranges from 190 nm to 369 nm. The illuminator may be configured in various materials, geometries, sizes and designs.
    Type: Application
    Filed: May 20, 2013
    Publication date: October 3, 2013
    Inventors: ASIF KHAN, VINOD ADIVARAHAN, QHALID FAREED
  • Patent number: 8541817
    Abstract: An improved high breakdown voltage semiconductor device and method for manufacturing is provided. The device has a substrate and a AlaGa1-aN layer on the substrate wherein 0.1?a?1.00. A GaN layer is on the AlaGa1-aN layer. An In1-bGabN/GaN channel layer is on the GaN layer wherein 0.1?b?1.00. A AlcIndGa1-c-dN spacer layer is on the In1-bGabN/GaN layer wherein 0.1?c?1.00 and 0.0?d?0.99. A AleIn1-eN nested superlattice barrier layer is on the AlcIndGa1-c-dN spacer layer wherein 0.10?e?0.99. A AlfIngGa1-f-gN leakage suppression layer is on the AleIn1-eN barrier layer wherein 0.1?f?0.99 and 0.1?g?0.99 wherein the leakage suppression layer decreases leakage current and increases breakdown voltage during high voltage operation. A superstructure, preferably with metallic electrodes, is on the AlfIngGa1-f-gN leakage suppression layer.
    Type: Grant
    Filed: November 8, 2010
    Date of Patent: September 24, 2013
    Assignee: Nitek, Inc.
    Inventors: Qhalid Fareed, Vinod Adivarahan, Asif Khan
  • Patent number: 8507941
    Abstract: Ultraviolet light emitting illuminator, and method for fabricating same, comprises an array of ultraviolet light emitting diodes and a first and a second terminal. When an alternating current is applied across the first and second terminals and thus to each of the diodes, the illuminator emits ultraviolet light at a frequency corresponding to that of the alternating current. The illuminator includes a template with ultraviolet light emitting quantum wells, a first buffer layer with a first type of conductivity and a second buffer layer with a second type of conductivity, all deposited preferably over a strain-relieving layer. A first and second metal contact are applied to the semiconductor layers having the first and second type of conductivity, respectively, to complete the LED. The emission spectrum ranges from 190 nm to 369 nm. The illuminator may be configured in various materials, geometries, sizes and designs.
    Type: Grant
    Filed: June 6, 2009
    Date of Patent: August 13, 2013
    Assignee: Nitek, Inc.
    Inventors: Asif Khan, Vinod Adivarahan, Qhalid Fareed
  • Patent number: 8476125
    Abstract: Fabrication methods of a high frequency (sub-micron gate length) operation of AlInGaN/InGaN/GaN MOS-DHFET, and the HFET device resulting from the fabrication methods, are generally disclosed. The method of forming the HFET device generally includes a novel double-recess etching and a pulsed deposition of an ultra-thin, high-quality silicon dioxide layer as the active gate-insulator. The methods of the present invention can be utilized to form any suitable field effect transistor (FET), and are particular suited for forming high electron mobility transistors (HEMT).
    Type: Grant
    Filed: December 17, 2007
    Date of Patent: July 2, 2013
    Assignee: University of South Carolina
    Inventors: M. Asif Khan, Vinod Adivarahan
  • Publication number: 20130166597
    Abstract: A context object provides an interface between structured data present in a database, and relevant unstructured data that is available outside of the database. The context object includes an objective, and access to unstructured data is determined based upon the objective. According to certain embodiments a context object may be configured to store meta information related to the structured data, for example references in the form of active links to pertinent entries in an email system, a social network, a wild, and/or blog. Maintenance of the context object may be achieved through automated crawling techniques and/or manual intervention by the user.
    Type: Application
    Filed: December 22, 2011
    Publication date: June 27, 2013
    Applicant: SAP AG
    Inventors: Mohammad Asif Khan, Christian Butzlaff, Christian Hauschild
  • Patent number: 8415654
    Abstract: A low resistance light emitting device with an ultraviolet light-emitting structure having a first layer with a first conductivity, a second layer with a second conductivity; and a light emitting quantum well region between the first layer and second layer. A first electrical contact is in electrical connection with the first layer and a second electrical contact is in electrical connection with the second layer. A template serves as a platform for the light-emitting structure. The ultraviolet light-emitting structure has a first layer having a first portion and a second portion of AlXInYGa(1-X-Y)N with an amount of elemental indium, the first portion surface being treated with silicon and indium containing precursor sources, and a second layer. When an electrical potential is applied to the first layer and the second layer the device emits ultraviolet light.
    Type: Grant
    Filed: March 27, 2009
    Date of Patent: April 9, 2013
    Assignee: Nitek, Inc.
    Inventors: Asif Khan, Qhalid Fareed, Vinod Adivarahan
  • Patent number: 8372697
    Abstract: Novel silicon dioxide and silicon nitride deposition methods are generally disclosed. In one embodiment, the method includes depositing silicon on the surface of a substrate having a temperature of between about 65° C. and about 350° C. The heated substrate is exposed to a silicon source that is substantially free from an oxidizing agent. The silicon on the surface is then oxidized with an oxygen source that is substantially free from a silicon source. As a result of oxidizing the silicon, a silicon oxide layer forms on the surface of the substrate. Alternatively, or in additionally, a nitrogen source can be provided to produce silicon nitride on the surface of the substrate.
    Type: Grant
    Filed: May 7, 2007
    Date of Patent: February 12, 2013
    Assignee: University of South Carolina
    Inventors: Asif Khan, Vinod Adivarahan
  • Publication number: 20130017689
    Abstract: Novel silicon dioxide and silicon nitride deposition methods are generally disclosed. In one embodiment, the method includes depositing silicon on the surface of a substrate having a temperature of between about 65° C. and about 350° C. The heated substrate is exposed to a silicon source that is substantially free from an oxidizing agent. The silicon on the surface is then oxidized with an oxygen source that is substantially free from a silicon source. As a result of oxidizing the silicon, a silicon oxide layer forms on the surface of the substrate. Alternatively, or in additionally, a nitrogen source can be provided to produce silicon nitride on the surface of the substrate.
    Type: Application
    Filed: May 7, 2007
    Publication date: January 17, 2013
    Inventors: Asif Khan, Vinod Adivarahan
  • Patent number: 8354687
    Abstract: A high efficiency light emitting diode with an ultraviolet light-emitting structure. The structure has a first layer with a first conductivity comprising Al1-x-yInyGaxN wherein 0?x?1 and 0?y?1; a second layer with a second conductivity comprising Al1-x-yInyGaxN wherein 0?x?1 and 0?y?1; and a light emitting quantum well region between said first layer and said second layer comprising Al1-x-yInyGaxN wherein 0?x?1 and 0?y?1. The diode also has a carrier bonded to said first layer and said second layer wherein said carrier has a thermal conductivity of at least 100 W/mK and said carrier is resistive between a bonding location of said first layer and a second bonding location of said second layer.
    Type: Grant
    Filed: July 30, 2009
    Date of Patent: January 15, 2013
    Assignee: Nitek, Inc.
    Inventors: Vinod Adivarahan, Asif Khan, Qhalid Fareed
  • Patent number: 8354663
    Abstract: An ultra-violet light-emitting diode (LED) array, 12, and method for fabricating same with an AlInGaN multiple-quantum-well active region, 500, exhibiting stable cw-powers. The LED includes a template, 10, with an ultraviolet light-emitting array structure on it. The template includes a first buffer layer, 321, then a second buffer layer, 421, on the first preferably with a strain-relieving layer in both buffer layers. Next there is a semiconductor layer having a first type of conductivity, 500, followed by a layer providing a quantum-well region, 600, with an emission spectrum ranging from 190 nm to 369 nm. Another semiconductor layer having a second type of conductivity is applied next, 800. A first metal contact, 980, is a charge spreading layer in electrical contact with the first layer and between the array of LED's. A second contact, 990, is applied to the semiconductor layer having the second type of conductivity, to complete the LED.
    Type: Grant
    Filed: August 13, 2008
    Date of Patent: January 15, 2013
    Assignee: Nitek, Inc.
    Inventors: Vinod Adivarahan, Asif Khan, Rubina Khan
  • Patent number: 8338273
    Abstract: An epitaxy procedure for growing extremely low defect density non-polar and semi-polar III-nitride layers over a base layer, and the resulting structures, is generally described. In particular, a pulsed selective area lateral overgrowth of a group III nitride layer can be achieved on a non-polar and semi-polar base layer. By utilizing the novel P-MOCVD or PALE and lateral over growth over selected area, very high lateral growth conditions can be achieved at relatively lower growth temperature which does not affect the III-N surfaces.
    Type: Grant
    Filed: December 17, 2007
    Date of Patent: December 25, 2012
    Assignee: University of South Carolina
    Inventors: M. Asif Khan, Vinod Adivarahan
  • Patent number: 8318562
    Abstract: Methods of achieving high breakdown voltages in semiconductor devices by suppressing the surface flashover using high dielectric strength insulating encapsulation material are generally described. In one embodiment of the present invention, surface flashover in AlGaN/GaN heterostructure field-effect transistors (HFETs) is suppressed by using high dielectric strength insulating encapsulation material. Surface flashover in as-fabricated III-Nitride based HFETs limits the operating voltages at levels well below the breakdown voltages of GaN.
    Type: Grant
    Filed: April 2, 2008
    Date of Patent: November 27, 2012
    Assignee: University of South Carolina
    Inventors: M. Asif Khan, Vinod Adivarahan, Qhalid Fareed, Grigory Simin, Naveen Tipirneni
  • Publication number: 20120294879
    Abstract: Pandemic A(H1N1) continues its global spread, and vaccine production is a serious problem. Protection by current vaccines is limited by the mutational differences that rapidly accumulate in the circulating strains, especially in the virus surface proteins. New vaccine strategies are focusing at conserved regions of the viral internal proteins to produce T cell epitope-based vaccines. T cell responses have been shown to reduce morbidity and promote recovery in mouse models of influenza challenge. We previously reported 54 highly conserved sequences of NP, M1 and the polymerases of all human H1N1, H3N2, H1N2, and H5N1, and avian subtypes over the past 30 years. Sixty-three T cell epitopes elicited responses in HLA transgenic mice (A2, A24, B7, DR2, DR3 and DR4). These epitopes were compared to the 2007-2009 human H1N1 sequences to identify conserved and variant residues.
    Type: Application
    Filed: October 13, 2010
    Publication date: November 22, 2012
    Applicants: NATIONAL UNIVERSITY OF SINGAPORE, THE JOHNS HOPKINS UNIVERSITY
    Inventors: J. Thomas August, Paul ThiamJoo Tan, Tin Wee Tan, Mohammad Asif Khan