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).

  • Patent number: 10199524
    Abstract: Photovoltaic devices such as solar cells having one or more field-effect hole or electron inversion/accumulation layers as contact regions are configured such that the electric field required for charge inversion and/or accumulation is provided by the output voltage of the photovoltaic device or that of an integrated solar cell unit. In some embodiments, a power source may be connected between a gate electrode and a contact region on the opposite side of photovoltaic device. In other embodiments, the photovoltaic device or integrated unit is self-powering.
    Type: Grant
    Filed: January 13, 2012
    Date of Patent: February 5, 2019
    Assignee: International Business Machines Corporation
    Inventors: Bahman Hekmatshoartabari, Devendra K. Sadana, Wilfried E. Haensch, Ghavam G. Shahidi, Davood Shahrjerdi
  • Patent number: 10177266
    Abstract: A photovoltaic device and method include a substrate coupled to an emitter side structure on a first side of the substrate and a back side structure on a side opposite the first side of the substrate. The emitter side structure or the back side structure include layers alternating between wide band gap layers and narrow band gap layers to provide a multilayer contact with an effectively increased band offset with the substrate and/or an effectively higher doping level over a single material contact. An emitter contact is coupled to the emitter side structure on a light collecting end portion of the device. A back contact is coupled to the back side structure opposite the light collecting end portion.
    Type: Grant
    Filed: December 22, 2015
    Date of Patent: January 8, 2019
    Assignee: International Business Machines Corporation
    Inventors: Bahman Hekmatshoar-Tabari, Devendra K. Sadana, Ghavam G. Shahidi, Davood Shahrjerdi
  • Patent number: 10170361
    Abstract: The present disclosure relates to integrated circuits and to methods of manufacturing interconnects of integrated circuits. For example, an integrated circuit includes a surface of the integrated circuit and an interconnect formed on the surface and comprising a metal. An average grain size of the metal of the interconnect is greater than or equal to at least half of a line width of the interconnect. In another example, a method for manufacturing an interconnect of an integrated circuit includes depositing a layer of a metal onto a surface of the integrated circuit, annealing the metal, patterning a first hard mask for placement over the metal and forming a line of the interconnect and a first via of the interconnect by performing a timed etch of the metal using the first hard mask.
    Type: Grant
    Filed: May 28, 2014
    Date of Patent: January 1, 2019
    Assignee: International Business Machines Corporation
    Inventors: Robert L Bruce, Cyril Cabral, Jr., Gregory M Fritz, Eric A Joseph, Michael F Lofaro, Hiroyuki Miyazoe, Kenneth P Rodbell, Ghavam G Shahidi
  • Patent number: 10141461
    Abstract: A method for forming a multi-junction photovoltaic device includes providing a germanium layer and etching pyramidal shapes in the germanium layer such that (111) facets are exposed to form a textured surface. A first p-n junction is formed on or over the textured surface from III-V semiconductor materials. Another p-n junction is formed over the first p-n junction from III-V semiconductor materials and follows the textured surface.
    Type: Grant
    Filed: July 13, 2015
    Date of Patent: November 27, 2018
    Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Bahman Hekmatshoartabari, Ali Khakifirooz, Ghavam G. Shahidi, Davood Shahrjerdi
  • Publication number: 20180331052
    Abstract: A method of forming a semiconductor detector including: forming a p-n junction diode in an active device layer of a silicon-on-insulator (SOI) substrate, the active device layer being formed on an insulator layer of the SOI substrate; forming a first opening through the insulator layer to access a backside of a first doped region of the diode, the first doped region underlying a second doped region of the diode; forming a back contact on a back surface of the first doped region and electrically connecting with the first doped region; forming a conductive interconnect layer on an upper surface of the SOI substrate, the interconnect layer including a first top contact providing electrical connection with the second doped region; and forming an electrode in the first opening on the backside of the detector structure, the electrode providing electrical connection with the back contact of the diode.
    Type: Application
    Filed: July 11, 2018
    Publication date: November 15, 2018
    Inventors: Bahman Hekmatshoartabari, Ghavam G. Shahidi
  • Publication number: 20180331157
    Abstract: A photovoltaic device including a photovoltaic cell and method of use is disclosed. The photovoltaic cell includes at least a first photovoltaic layer and a second photovoltaic layer arranged in a stack. The first photovoltaic layer has a first thickness and receives light at its top surface. A second photovoltaic layer has a second thickness and is disposed beneath the first photovoltaic layer and receives light passing through the first photovoltaic layer. The first thickness and the second thickness are selected so that a first light absorption at the first photovoltaic layer is equal to a second light absorption at the second photovoltaic layer. The photovoltaic cell is irradiated at its top surface with monochromatic light to generate a current.
    Type: Application
    Filed: May 15, 2017
    Publication date: November 15, 2018
    Inventors: Stephen W. Bedell, Ning Li, Qinglong Li, Kunal Mukherjee, Devendra Sadana, Ghavam G. Shahidi
  • Publication number: 20180331158
    Abstract: A photovoltaic device including a photovoltaic cell and method of use is disclosed. The photovoltaic cell includes at least a first photovoltaic layer and a second photovoltaic layer arranged in a stack. The first photovoltaic layer has a first thickness and receives light at its top surface. A second photovoltaic layer has a second thickness and is disposed beneath the first photovoltaic layer and receives light passing through the first photovoltaic layer. The first thickness and the second thickness are selected so that a first light absorption at the first photovoltaic layer is equal to a second light absorption at the second photovoltaic layer. The photovoltaic cell is irradiated at its top surface with monochromatic light to generate a current.
    Type: Application
    Filed: November 15, 2017
    Publication date: November 15, 2018
    Inventors: Stephen W. Bedell, Ning Li, Qinglong Li, Kunal Mukherjee, Devendra Sadana, Ghavam G. Shahidi
  • Patent number: 10128452
    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: Grant
    Filed: March 1, 2017
    Date of Patent: November 13, 2018
    Assignee: International Business Machines Corporation
    Inventors: Ali Afzali-Ardakani, Tze-Chiang Chen, Bahman Hekmatshoartabari, Ghavam G. Shahidi
  • Publication number: 20180323330
    Abstract: A photovoltaic device that includes an upper cell that absorbs a first range of wavelengths of light and a bottom cell that absorbs a second range of wavelengths of light. The bottom cell includes a heterojunction comprising a crystalline germanium containing (Ge) layer. At least one surface of the crystalline germanium (Ge) containing layer is in contact with a silicon (Si) containing layer having a larger band gap than the crystalline (Ge) containing layer.
    Type: Application
    Filed: July 13, 2018
    Publication date: November 8, 2018
    Inventors: Keith E. Fogel, Bahman Hekmatshoartabari, Devendra K. Sadana, Ghavam G. Shahidi, Davood Shahrjerdi
  • Publication number: 20180323319
    Abstract: A photovoltaic device that includes a p-n junction of first type III-V semiconductor material layers, and a window layer of a second type III-V semiconductor material on the light receiving end of the p-n junction, wherein the second type III-V semiconductor material has a greater band gap than the first type III-V semiconductor material, and the window layer of the photovoltaic device has a cross-sectional area of microscale.
    Type: Application
    Filed: May 3, 2017
    Publication date: November 8, 2018
    Inventors: Talia S. Gershon, Ning Li, Devendra K. Sadana, Ghavam G. Shahidi
  • Patent number: 10121786
    Abstract: In one aspect, a method of forming finFET devices is provided which includes patterning fins in a wafer; forming dummy gates over the fins; forming spacers on opposite sides of the dummy gates; depositing a gap fill oxide on the wafer, filling any gaps between the spacers; removing the dummy gates forming gate trenches; trimming the fins within the gate trenches such that a width of the fins within the gate trenches is less than the width of the fins under the spacers adjacent to the gate trenches, wherein u-shaped grooves are formed in sides of the fins within the gate trenches; and forming replacement gate stacks in the gate trenches, wherein portions of the fins adjacent to the replacement gate stacks serve as source and drain regions of the finFET devices.
    Type: Grant
    Filed: March 20, 2017
    Date of Patent: November 6, 2018
    Assignee: International Business Machines Corporation
    Inventors: Takashi Ando, Robert H. Dennard, Isaac Lauer, Ramachandran Muralidhar, Ghavam G. Shahidi
  • Publication number: 20180316062
    Abstract: A method for forming a thin film lithium ion battery includes, under a same vacuum seal, forming a stack of layers on a substrate including an anode layer, an electrolyte, a cathode layer and a first cap over the stack of layers to protect the layers from air. Under a same vacuum seal, the stack of layers is etched with a non-reactive etch process in accordance with a hardmask, and a second cap layer is formed over the stack of layers without breaking the vacuum seal. Contacts coupled to the cathode and the anode are formed.
    Type: Application
    Filed: July 3, 2018
    Publication date: November 1, 2018
    Inventors: Effendi Leobandung, Ghavam G. Shahidi
  • Patent number: 10115833
    Abstract: A junction field effect transistor (JFET) comprises an insulating carrier substrate, a base semiconductor substrate formed on the insulating carrier substrate and a gate region formed on the base semiconductor substrate. The gate region forms a junction with the base semiconductor substrate. The JFET further comprises a first source/drain region formed on the base semiconductor substrate and located on a first side of the gate region and a second source/drain region formed on the base semiconductor substrate and located on a second side of the gate region. A gate stack is deposited on the gate region, a first source/drain stack is deposited on the first source/drain region and a second source/drain stack is deposited on the second source/drain region. At least one of the gate stack, first source/drain stack and second source/drain stack overlaps onto another one of the gate stack, first source/drain stack and second source/drain stack.
    Type: Grant
    Filed: April 26, 2017
    Date of Patent: October 30, 2018
    Assignee: International Business Machines Corporation
    Inventors: Bahman Hekmatshoartabari, Ghavam G. Shahidi, Yanning Sun
  • Publication number: 20180308432
    Abstract: A method for forming a pixel circuit includes forming transistors on a substrate; forming a passivation layer over the transistors; forming a contact hole to a source of a transistor; forming a transparent conductor that forms a contact in the contact hole and a resistor to control pixel current; and forming an organic light emitting diode (OLED) with an anode connecting to the resistor.
    Type: Application
    Filed: June 22, 2018
    Publication date: October 25, 2018
    Inventors: Bahman Hekmatshoartabari, Ghavam G. Shahidi
  • Publication number: 20180308431
    Abstract: A pixel circuit includes a circuit element connected to a gate of a first transistor and ground, which receives a select input. A data line is coupled to a first source/drain of the first transistor, and a second source/drain of the first transistor is coupled to a gate of a second transistor. The second transistor has a drain connected to a supply voltage and a source connected to a resistive element. The resistive element connects to an organic light emitting diode (OLED), which connects to the ground.
    Type: Application
    Filed: June 22, 2018
    Publication date: October 25, 2018
    Inventors: Bahman Hekmatshoartabari, Ghavam G. Shahidi
  • Patent number: 10109709
    Abstract: A method of forming a semiconductor structure includes forming a dummy gate above a semiconductor substrate. The dummy gate defines a source-drain region adjacent to the dummy gate and a channel region below the dummy gate. A silicon-germanium layer is epitaxially grown above the source-drain region with a target concentration of germanium atoms. The semiconductor structure is annealed to diffuse the germanium atoms from the silicon-germanium layer into the channel region to form a silicon-germanium channel region.
    Type: Grant
    Filed: August 19, 2015
    Date of Patent: October 23, 2018
    Assignee: International Business Machines Corporation
    Inventors: Kangguo Cheng, Ali Khakifirooz, Alexander Reznicek, Ghavam G. Shahidi
  • Publication number: 20180301571
    Abstract: A method of forming a photovoltaic device that includes epitaxially growing a first conductivity type semiconductor material of a type III-V semiconductor on a semiconductor substrate. The first conductivity type semiconductor material continuously extending along an entirety of the semiconductor substrate in a plurality of triangular shaped islands; and conformally forming a layer of type III-V semiconductor material having a second conductivity type on the plurality of triangular shaped islands.
    Type: Application
    Filed: April 13, 2017
    Publication date: October 18, 2018
    Inventors: Stephen W. Bedell, Ning Li, Devendra K. Sadana, Ghavam G. Shahidi
  • Publication number: 20180301572
    Abstract: A method of forming a photovoltaic device that includes epitaxially growing a first conductivity type semiconductor material of a type III-V semiconductor on a semiconductor substrate. The first conductivity type semiconductor material continuously extending along an entirety of the semiconductor substrate in a plurality of triangular shaped islands; and conformally forming a layer of type III-V semiconductor material having a second conductivity type on the plurality of triangular shaped islands.
    Type: Application
    Filed: December 7, 2017
    Publication date: October 18, 2018
    Inventors: Stephen W. Bedell, Ning Li, Devendra K. Sadana, Ghavam G. Shahidi
  • Publication number: 20180301593
    Abstract: Provided is a light emitting semiconductor structure that operates as a light emitting diode (LED). In embodiments of the invention, the light emitting semiconductor structure includes a first barrier region, a second barrier region, and a single quantum well having a preselected thickness between the first barrier region and the second barrier region. The preselected thickness according to embodiments is selected to achieve a predetermined charge density in the quantum well. The predetermined charge density according to embodiments results from a predetermined bias current applied to the semiconductor structure. The predetermined bias current according to embodiments comprises less than about 1 mA.
    Type: Application
    Filed: June 26, 2018
    Publication date: October 18, 2018
    Inventors: Ning Li, Qinglong Li, Kunal Mukherjee, Devendra K. Sadana, Ghavam G. Shahidi
  • Publication number: 20180301567
    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: June 21, 2018
    Publication date: October 18, 2018
    Inventors: Bahman Hekmatshoartabari, Ghavam G. Shahidi