Patents by Inventor Ghavam G. Shahidi

Ghavam G. Shahidi 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).

  • 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
  • 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
  • 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: 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
  • Publication number: 20150236282
    Abstract: Junction field-effect transistors including inorganic channels and organic gate junctions are used in some applications for forming high resolution active matrix displays. Arrays of such junction field-effect 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, Tze-Chiang Chen, Bahman Hekmatshoartabari, Ghavam G. Shahidi
  • 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
  • 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: 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: 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: 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
  • Publication number: 20150214117
    Abstract: Silicon and silicon germanium fins are formed on a semiconductor wafer or other substrate in a manner that facilitates production of closely spaced nFET and pFET devices. A patterned mandrel layer is employed for forming one or more recesses in the wafer prior to the epitaxial growth of a silicon germanium layer that fills the recess. Spacers are formed on the side walls of the patterned mandrel layer followed by removal of the mandrel layer. The exposed areas of the wafer and silicon germanium layer between the spacers are etched to form fins usable for nFET devices from the wafer and fins usable for pFET devices from the silicon germanium layer.
    Type: Application
    Filed: April 3, 2015
    Publication date: July 30, 2015
    Inventors: KANGGUO CHENG, ALI KHAKIFIROOZ, ALEXANDER REZNICEK, GHAVAM G. SHAHIDI
  • Patent number: 9093533
    Abstract: Silicon and silicon germanium fins are formed on a semiconductor wafer or other substrate in a manner that facilitates production of closely spaced nFET and pFET devices. A patterned mandrel layer is employed for forming one or more recesses in the wafer prior to the epitaxial growth of a silicon germanium layer that fills the recess. Spacers are formed on the side walls of the patterned mandrel layer followed by removal of the mandrel layer. The exposed areas of the wafer and silicon germanium layer between the spacers are etched to form fins usable for nFET devices from the wafer and fins usable for pFET devices from the silicon germanium layer.
    Type: Grant
    Filed: July 24, 2013
    Date of Patent: July 28, 2015
    Assignee: International Business Machines Corporation
    Inventors: Kangguo Cheng, Ali Khakifirooz, Alexander Reznicek, Ghavam G. Shahidi
  • 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
  • Publication number: 20150206947
    Abstract: A junction field-effect transistor (JFET) with a gate region that includes two separate sub-regions having material of different conductivity types and/or a Schottky junction that substantially suppresses gate current when the gate junction is forward-biased, as well as complementary circuits that incorporate such JFET devices.
    Type: Application
    Filed: January 7, 2015
    Publication date: July 23, 2015
    Inventors: Bahman Hekmatshoartabari, Ghavam G. Shahidi
  • Patent number: 9087705
    Abstract: Complementary circuits based on junction (or heterojunction) field effect transistor devices and bipolar junction (or heterojunction) transistor devices comprised of thin crystalline semiconductor-on-insulator substrates are provided which are compatible with low-cost and/or flexible substrates. Only one substrate doping type (i.e., n-type or p-type) is required for providing the complementary circuits and thus the number of masks (typically three or four) remains the same as that required for either n-channel or p-channel devices in the TFT level.
    Type: Grant
    Filed: June 5, 2013
    Date of Patent: July 21, 2015
    Assignee: International Business Machines Corporation
    Inventors: Tze-Chiang Chen, Bahman Hekmatshoar-Tabari, Ghavam G. Shahidi, Davood Shahrjerdi
  • Patent number: 9087772
    Abstract: A method for forming a semiconductor device includes forming a gate stack on a monocrystalline substrate. A surface of the substrate adjacent to the gate stack and below a portion of the gate stack is amorphorized. The surface is etched to selectively remove a thickness of amorphorized portions to form undercuts below the gate stack. A layer is epitaxially grown in the thickness and the undercuts to form an extension region for the semiconductor device. Devices are also provided.
    Type: Grant
    Filed: September 12, 2012
    Date of Patent: July 21, 2015
    Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Isaac Lauer, Effendi Leobandung, Ghavam G. Shahidi
  • Publication number: 20150200107
    Abstract: A method for fabricating the device includes patterning a first structure and a second structure on a semiconductor device. A first angled ion implantation is applied to the second structure such that the first structure is protected and a second angled ion implantation is applied to the first structure such that the second structure is protected, wherein exposed portions of the first and second structures have an altered rate of oxidation. Oxidation is performed to form thicker or thinner oxide portions on the exposed portions of the first and second structures relative to unexposed portions of the first and second structures. Oxide portions are removed to an underlying layer of the first and second structures. The first and second structures are removed. Spacers are formed about a periphery of remaining oxide portions. The remaining oxide portions are removed. A layer below the spacers is patterned to form integrated circuit features.
    Type: Application
    Filed: March 25, 2015
    Publication date: July 16, 2015
    Inventors: Kangguo Cheng, Bruce B. Doris, Ali Khakifirooz, Ghavam G. Shahidi
  • Publication number: 20150194562
    Abstract: A photovoltaic device including a single junction solar cell provided by an absorption layer of a type IV semiconductor material having a first conductivity, and an emitter layer of a type III-V semiconductor material having a second conductivity, wherein the type III-V semiconductor material has a thickness that is no greater than 50 nm.
    Type: Application
    Filed: March 19, 2015
    Publication date: July 9, 2015
    Inventors: Bahman Hekmatshoar-Tabri, Ali Khakifirooz, Devendra K. Sadana, Ghavam G. Shahidi, Davood Shahrjerdi
  • Patent number: 9070788
    Abstract: An circuit supporting substrate includes a transistor and a capacitor. The transistor includes a first semiconductor layer and a gate stack located on the first semiconductor layer. The gate stack includes a metal layer and a first high-k dielectric layer. A gate spacer is located on sidewalls of the gate stack. The first high-k dielectric layer is located between the first semiconductor layer and the metal layer and between the gate spacer and sidewalls of the metal layer. A first silicide region is located on a first source/drain region. A second silicide region is located on a second source/drain region. The capacitor includes a first terminal that comprises a third silicide region located on a portion of the second semiconductor. A second high-k dielectric layer is located on the silicide region. A second terminal comprises a metal layer that is located on the second high-k dielectric layer.
    Type: Grant
    Filed: January 30, 2014
    Date of Patent: June 30, 2015
    Assignee: International Business Machines Corporation
    Inventors: Kangguo Cheng, Bruce Doris, Ali Khakifirooz, Ghavam G. Shahidi