Patents by Inventor Davood Shahrjerdi

Davood Shahrjerdi 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: 9136402
    Abstract: A flexible solar cell comprises an epitaxially grown III-V layer having a first layer grown on a base substrate, at least one intermediate layer grown on the first layer, and a cap layer grown on the at least one intermediate layer, the III-V layer being separated from the base substrate by controllably spalling the first layer from the base substrate; and a flexible substrate coupled to the epitaxially grown III-V layer. The flexible solar cell may be used to provide power to an electronic device.
    Type: Grant
    Filed: October 22, 2012
    Date of Patent: September 15, 2015
    Assignee: International Business Machines Corporation
    Inventors: Stephen W. Bedell, Bahman Hekmatshoartabari, Devendra K. Sadana, Ghavam G. Shahidi, Davood Shahrjerdi
  • Publication number: 20150255541
    Abstract: A back end of line device and method for fabricating a transistor device include a substrate having an insulating layer formed thereon and a channel layer formed on the insulating layer. A gate structure is formed on the channel layer. Dopants are implanted into an upper portion of the channel layer on opposite sides of the gate structure to form shallow source and drain regions using a low temperature implantation process. An epitaxial layer is selectively grown on the shallow source and drain regions to form raised regions above the channel layer and against the gate structure using a low temperature plasma enhanced chemical vapor deposition process, wherein low temperature is less than about 400 degrees Celsius.
    Type: Application
    Filed: May 22, 2015
    Publication date: September 10, 2015
    Inventors: WILFRIED E. HAENSCH, BAHMAN HEKMATSHOAR-TABARI, ALI KHAKIFIROOZ, TAK H. NING, GHAVAM G. SHAHIDI, DAVOOD SHAHRJERDI
  • Publication number: 20150255574
    Abstract: A back end of line device and method for fabricating a transistor device include a substrate having an insulating layer formed thereon and a channel layer formed on the insulating layer. A gate structure is formed on the channel layer. Dopants are implanted into an upper portion of the channel layer on opposite sides of the gate structure to form shallow source and drain regions using a low temperature implantation process. An epitaxial layer is selectively grown on the shallow source and drain regions to form raised regions above the channel layer and against the gate structure using a low temperature plasma enhanced chemical vapor deposition process, wherein low temperature is less than about 400 degrees Celsius.
    Type: Application
    Filed: May 22, 2015
    Publication date: September 10, 2015
    Inventors: WILFRIED E. HAENSCH, BAHMAN HEKMATSHOAR-TABARI, ALI KHAKIFIROOZ, TAK H. NING, GHAVAM G. SHAHIDI, DAVOOD SHAHRJERDI
  • Publication number: 20150255666
    Abstract: A method for fabricating a device with integrated photovoltaic cells includes supporting a semiconductor substrate on a first handle substrate and doping the semiconductor substrate to form doped alternating regions with opposite conductivity. A doped layer is formed over a first side the semiconductor substrate. A conductive material is patterned over the doped layer to form conductive islands such that the conductive islands are aligned with the alternating regions to define a plurality of photovoltaic cells connected in series on a monolithic structure.
    Type: Application
    Filed: May 21, 2015
    Publication date: September 10, 2015
    Inventors: STEPHEN W. BEDELL, BAHMAN HEKMATSHOARTABARI, DEVENDRA K. SADANA, GHAVAM G. SHAHIDI, DAVOOD SHAHRJERDI
  • Publication number: 20150255664
    Abstract: A photovoltaic device and method include a doped germanium-containing substrate, an emitter contact coupled to the substrate on a first side and a back contact coupled to the substrate on a side opposite the first side. The emitter includes at least one doped layer of an opposite conductivity type as that of the substrate and the back contact includes at least one doped layer of the same conductivity type as that of the substrate. The at least one doped layer of the emitter contact or the at least one doped layer of the back contact is in direct contact with the substrate, and the at least one doped layer of the emitter contact or the back contact includes an n-type material having an electron affinity smaller than that of the substrate, or a p-type material having a hole affinity larger than that of the substrate.
    Type: Application
    Filed: May 20, 2015
    Publication date: September 10, 2015
    Inventors: Stephen W. Bedell, Keith E. Fogel, Bahman Hekmatshoar-Tabari, Devendra K. Sadana, Ghavam G. Shahidi, Davood Shahrjerdi
  • Patent number: 9130105
    Abstract: A method for fabrication a light emitting diode (LED) includes growing a crystalline LED structure on a growth substrate, forming alternating material layers on the LED structure to form a reflector on a back side opposite the growth substrate and depositing a stressor layer on the reflector. A handle substrate is adhered to the stressor layer. The LED structure is separated from the growth substrate using a spalling process to expose a front side of the LED structure.
    Type: Grant
    Filed: September 9, 2013
    Date of Patent: September 8, 2015
    Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Stephen W. Bedell, Bahman Hekmatshoartabari, Devendra K. Sadana, Davood Shahrjerdi
  • Patent number: 9125575
    Abstract: High resolution active matrix nanowire circuits enable a flexible and stretchable platform for probing neural circuits. Fabrication of such circuits includes forming an array of transistors using a semiconductor-on-insulator substrate. Electrically isolated arrays of vertically extending, electrically conductive wires are formed from a doped, electrically conductive layer within the substrate, each of the arrays of wires being electrically connected to a transistor in the array of transistors.
    Type: Grant
    Filed: February 20, 2014
    Date of Patent: September 8, 2015
    Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Bahman Hekmatshoartabari, Ali Khakifirooz, Ghavam G. Shahidi, Davood Shahrjerdi
  • Publication number: 20150247259
    Abstract: An epitaxy method includes providing an exposed crystalline region of a substrate material. Silicon is epitaxially deposited on the substrate material in a low temperature process wherein a deposition temperature is less than 500 degrees Celsius. A source gas is diluted with a dilution gas with a gas ratio of dilution gas to source gas of less than 1000.
    Type: Application
    Filed: May 13, 2015
    Publication date: September 3, 2015
    Inventors: BAHMAN HEKMATSHOAR-TABARI, ALI KHAKIFIROOZ, ALEXANDER REZNICEK, DEVENDRA K. SADANA, GHAVAM G. SHAHIDI, DAVOOD SHAHRJERDI
  • Publication number: 20150249188
    Abstract: A method for forming a light emitting device includes forming a monocrystalline III-V emissive layer on a monocrystalline substrate and forming a first doped layer on the emissive layer. A first contact is deposited on the first doped layer. The monocrystalline substrate is removed from the emissive layer by a mechanical process. A second doped layer is formed on the emissive layer on a side from which the substrate has been removed. The second doped layer has a dopant conductivity opposite that of the first doped layer. A second contact is deposited on the second doped layer.
    Type: Application
    Filed: May 13, 2015
    Publication date: September 3, 2015
    Inventors: Tze-Chiang Chen, Bahman Hekmatshoartabari, Devendra K. Sadana, Ghavam G. Shahidi, Davood Shahrjerdi
  • Patent number: 9123842
    Abstract: A photoreceptor includes a multilayer blocking structure to reduce dark discharge of the surface voltage of the photoreceptor resulting from electron injection from an electrically conductive substrate. The multilayer blocking structure includes wide band gap semiconductor layers in alternating sequence with one or more narrow band gap blocking layers. A fabrication method of the photoreceptor includes transfer-doping of the narrow band gap blocking layers, which are deposited in alternating sequence with wide band gap semiconductor layers to form a blocking structure. Suppression of hole or electron injection can be obtained using the method.
    Type: Grant
    Filed: July 20, 2012
    Date of Patent: September 1, 2015
    Assignee: International Business Machines Corporation
    Inventors: Bahman Hekmatshoartabari, Jeehwan Kim, Devendra K. Sadana, Ghavam G. Shahidi, Davood Shahrjerdi
  • Publication number: 20150243497
    Abstract: A back end of line device and method for fabricating a transistor device include a substrate having an insulating layer formed thereon and a channel layer formed on the insulating layer. A gate structure is formed on the channel layer. Dopants are implanted into an upper portion of the channel layer on opposite sides of the gate structure to form shallow source and drain regions using a low temperature implantation process. An epitaxial layer is selectively grown on the shallow source and drain regions to form raised regions above the channel layer and against the gate structure using a low temperature plasma enhanced chemical vapor deposition process, wherein low temperature is less than about 400 degrees Celsius.
    Type: Application
    Filed: May 8, 2015
    Publication date: August 27, 2015
    Inventors: WILFRIED E. HAENSCH, BAHMAN HEKMATSHOAR-TABARI, ALI KHAKIFIROOZ, TAK H. NING, GHAVAM G. SHAHIDI, DAVOOD SHAHRJERDI
  • Publication number: 20150235908
    Abstract: An electrical device including a first conductivity semiconductor device present in a first semiconductor device region of an SOI substrate, and a second conductivity semiconductor device present in a second semiconductor device region of the SOI substrate. The electrical device also includes a diode present within a diode region of the SOI substrate that includes a first doped layer of a first conductivity semiconductor material that is present on an SOI layer of the SOI substrate. The first doped layer includes a first plurality of protrusions extending from a first connecting base portion. The semiconductor diode further includes a second doped layer of the second conductivity semiconductor material present over the first doped layer. The second doped layer including a second plurality of protrusions extending from a second connecting base portion.
    Type: Application
    Filed: May 6, 2015
    Publication date: August 20, 2015
    Inventors: Kangguo Cheng, Ali Khakifirooz, Ghavam G. Shahidi, Davood Shahrjerdi
  • Publication number: 20150236078
    Abstract: Bipolar junction transistors including inorganic channels and organic emitter junctions are used in some applications for forming high resolution active matrix displays. Arrays of such bipolar junction transistors are electrically connected to thin film switching transistors and provide high drive currents for passive devices such as organic light emitting diodes.
    Type: Application
    Filed: February 19, 2014
    Publication date: August 20, 2015
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Ali Afzali-Ardakani, Bahman Hekmatshoartabari, Tak H. Ning, Davood Shahrjerdi
  • Publication number: 20150230720
    Abstract: High resolution active matrix nanowire circuits enable a flexible and stretchable platform for probing neural circuits. Fabrication of such circuits includes forming an array of transistors using a semiconductor-on-insulator substrate. Electrically isolated arrays of vertically extending, electrically conductive wires are formed from a doped, electrically conductive layer within the substrate, each of the arrays of wires being electrically connected to a transistor in the array of transistors.
    Type: Application
    Filed: February 20, 2014
    Publication date: August 20, 2015
    Applicant: International Business Machines Corporation
    Inventors: Bahman Hekmatshoartabari, Ali Khakifirooz, Ghavam G. Shahidi, Davood Shahrjerdi
  • Patent number: 9105518
    Abstract: Methods for detecting the physical layout of an integrated circuit are provided. The methods of the present disclosure allow large area imaging of the circuit layout without requiring tedious sample preparation techniques. The imaging can be performed utilizing low-energy beam techniques such as scanning electron microscopy; however, more sophisticated imaging techniques can also be employed. In the methods of the present disclosure, spalling is used to remove a portion of a semiconductor layer including at least one semiconductor device formed thereon or therein from a base substrate. In some cases, a buried insulator layer that is located beneath a semiconductor layer including the at least one semiconductor device can be completely or partially removed. In some cases, the semiconductor layer including the at least one semiconductor device can be thinned. The methods improve the detection quality that the buried insulator layer and a thick semiconductor layer can reduce.
    Type: Grant
    Filed: October 25, 2013
    Date of Patent: August 11, 2015
    Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Stephen W. Bedell, Bahman Hekmatshoar-Tabari, Ali Khakifirooz, John A. Ott, Ghavam G. Shahidi, Davood Shahrjerdi
  • Patent number: 9105238
    Abstract: A pixel circuit for an active matrix organic light-emitting diode display system includes a first input node, a second input node, first power supply node, a second power supply node, a triode switch circuit, a storage capacitor, an organic light emitting diode, and a resistive element. The triode switch circuit is connected to the first and second input nodes. The storage capacitor is connected between an output of the triode switch circuit and the second power supply node. The organic light-emitting diode is connected between the output of the triode switch circuit and the second power supply node. The first resistive element is connected between the output of the triode switch circuit and the first power supply node.
    Type: Grant
    Filed: April 25, 2013
    Date of Patent: August 11, 2015
    Assignee: International Business Machines Corporation
    Inventors: Bahman Hekmatshoartabari, Davood Shahrjerdi
  • Patent number: 9105775
    Abstract: A multi-junction photovoltaic device includes a germanium layer having pyramidal shapes with (111) facets exposed to form a textured surface. A first p-n junction is formed on or over the textured surface. Another p-n junction is formed over the first p-n junction and following the textured surface.
    Type: Grant
    Filed: June 28, 2012
    Date of Patent: August 11, 2015
    Assignee: International Business Machines Corporation
    Inventors: Bahman Hekmatshoartabari, Ali Khakifirooz, Ghavam G. Shahidi, Davood Shahrjerdi
  • Patent number: 9099596
    Abstract: A photovoltaic device and method include a doped germanium-containing substrate, an emitter contact coupled to the substrate on a first side and a back contact coupled to the substrate on a side opposite the first side. The emitter includes at least one doped layer of an opposite conductivity type as that of the substrate and the back contact includes at least one doped layer of the same conductivity type as that of the substrate. The at least one doped layer of the emitter contact or the at least one doped layer of the back contact is in direct contact with the substrate, and the at least one doped layer of the emitter contact or the back contact includes an n-type material having an electron affinity smaller than that of the substrate, or a p-type material having a hole affinity larger than that of the substrate.
    Type: Grant
    Filed: July 29, 2011
    Date of Patent: August 4, 2015
    Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Stephen W. Bedell, Keith E. Fogel, Bahman Hekmatshoar-Tabari, Devendra K. Sadana, Ghavam G. Shahidi, Davood Shahrjerdi
  • Patent number: 9099585
    Abstract: A method of forming a semiconductor material of a photovoltaic device that includes providing a surface of a hydrogenated amorphous silicon containing material, and annealing the hydrogenated amorphous silicon containing material in a deuterium containing atmosphere. Deuterium from the deuterium-containing atmosphere is introduced to the lattice of the hydrogenated amorphous silicon containing material through the surface of the hydrogenated amorphous silicon containing material. In some embodiments, the deuterium that is introduced to the lattice of the hydrogenated amorphous silicon containing material increases the stability of the hydrogenated amorphous silicon containing material.
    Type: Grant
    Filed: September 6, 2012
    Date of Patent: August 4, 2015
    Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Bahman Hekmatshoar-Tabari, Marinus Hopstaken, Dae-Gyu Park, Devendra K. Sadana, Ghavam G. Shahidi, Davood Shahrjerdi
  • Patent number: 9093548
    Abstract: Junction field effect transistors are provided which include a gate junction located on a surface of a crystalline semiconductor material of a first conductivity type. The gate junction can be selected from one of a doped hydrogenated crystalline semiconductor material layer portion of a second conductivity type which is opposite the first conductivity type, a doped hydrogenated non-crystalline semiconductor material layer portion of a second conductivity type which is opposite the first conductivity type, and a Schottky contact.
    Type: Grant
    Filed: March 15, 2013
    Date of Patent: July 28, 2015
    Assignee: International Business Machines Corporation
    Inventors: Bahman Hekmatshoar-Tabari, Devendra K. Sadana, Ghavam G. Shahidi, Davood Shahrjerdi