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: 9018517
    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: Grant
    Filed: November 7, 2011
    Date of Patent: April 28, 2015
    Assignee: International Business Machines Corporation
    Inventors: Bahman Hekmatshoar-Tabari, Ali Khakifirooz, Devendra K. Sadana, Ghavam G. Shahidi, Davood Shahrjerdi
  • Publication number: 20150102359
    Abstract: A method of forming an active matrix, light emitting diode (LED) array includes removing, from a base substrate, a layer of inorganic LED material originally grown thereupon; and bonding the removed layer of inorganic LED material to an active matrix, thin film transistor (TFT) backplane array.
    Type: Application
    Filed: October 20, 2014
    Publication date: April 16, 2015
    Inventors: Stephen W. Bedell, Bahman Hekmatshoartabari, Devendra K. Sadana, Ghavam G. Shahidi, Davood Shahrjerdi
  • Publication number: 20150093872
    Abstract: A method of forming the heterojunction bipolar transistor that includes providing a stack of a base layer, an extrinsic base layer, a first metal containing layer, and a dielectric cap layer. The dielectric cap layer and the first metal containing layer may be etched to provide a base contact and a dielectric cap. Exposed portions of the base layer may be etched selectively to the dielectric cap. A remaining portion of the base layer provides the base region. A hydrogenated silicon containing layer may be deposited with a low temperature deposition method. At least a portion of the hydrogenated silicon containing layer is formed on at least sidewalls of the base region. A second metal containing layer may be formed on the hydrogenated silicon containing layer. The second metal containing and the hydrogenated silicon containing layer may be etched to provide an emitter region and a collector region.
    Type: Application
    Filed: October 1, 2013
    Publication date: April 2, 2015
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Kevin K. Chan, Bahman Hekmatshoartabari, Tak H. Ning, Davood Shahrjerdi
  • Patent number: 8980737
    Abstract: Methods of patterning semiconductor contact materials on a crystalline semiconductor material which allow high-quality interfaces between the crystalline semiconductor material and the patterned semiconductor contact material are provided. Blanket layers of passivation material and sacrificial material are formed on the crystalline semiconductor material. A first contact opening is formed into the blanker layer of sacrificial material. The first contact opening is extended into blanket layer of passivation material, stopping on a first surface portion of the crystalline semiconductor material, using remaining sacrificial material portions as an etch mask. A semiconductor contact material is formed on the exposed first surface portion of the crystalline semiconductor material. In some embodiments, an electrode material portion can be formed over the first contact opening, and then a second blanket layer of sacrificial material can be formed, followed by forming a next contact opening.
    Type: Grant
    Filed: March 15, 2013
    Date of Patent: March 17, 2015
    Assignee: International Business Machines Corporation
    Inventors: Bahman Hekmatshoar-Tabari, Tak H. Ning, Devendra K. Sadana, Ghavam G. Shahidi, Davood Shahrjerdi
  • Patent number: 8981449
    Abstract: A method of forming a semiconductor device that includes providing a logic device on a semiconductor on insulating layer of a transfer substrate. The transfer substrate may further include a dielectric layer and a first handle substrate. A second handle substrate may be contacted to the semiconductor on insulating layer of the transfer substrate that includes logic device. The first handle substrate may be removed to expose the dielectric layer. A memory device can then be formed on the dielectric layer. Interconnect wiring can then be formed connecting the logic device with the memory device.
    Type: Grant
    Filed: September 17, 2013
    Date of Patent: March 17, 2015
    Assignee: International Business Machines Corporation
    Inventors: Stephen W. Bedell, Bahman Hekmatshoar-Tabari, Ali Khakifirooz, Ghavam G. Shahidi, Davood Shahrjerdi
  • Publication number: 20150068604
    Abstract: A method cleaving a semiconductor material that includes providing a germanium substrate having a germanium and tin alloy layer is present therein. A stressor layer is deposited on a surface of the germanium substrate. A stress from the stressor layer is applied to the germanium substrate, in which the stress cleaves the germanium substrate to provide a cleaved surface. The cleaved surface of the germanium substrate is then selective to the germanium and tin alloy layer of the germanium substrate. In another embodiment, the germanium and tin alloy layer may function as a fracture plane during a spalling method.
    Type: Application
    Filed: November 13, 2014
    Publication date: March 12, 2015
    Inventors: Stephen W. Bedell, Devendra K. Sadana, Davood Shahrjerdi
  • Publication number: 20150069333
    Abstract: High resolution active matrix structures are fabricated using techniques applicable to flexible substrates. A backplane layer including active semiconductor devices is formed using a semiconductor-on-insulator substrate. The substrate is thinned using a layer transfer technique or chemical/mechanical processing. Driver transistors are formed on the semiconductor layer of the substrate along with additional circuits that provide other functions such as computing or sensing. Contacts to passive devices such as organic light emitting diodes may be provided by heavily doped regions formed in the handle layer of the substrate and then isolated. A gate dielectric layer may be formed on the semiconductor layer, which functions as a channel layer, or the insulator layer of the substrate may be employed as a gate dielectric layer.
    Type: Application
    Filed: September 6, 2013
    Publication date: March 12, 2015
    Applicant: International Business Machines Corporation
    Inventors: Stephen W. Bedell, III, Bahman Hekmatshoartabari, Ghavam G. Shahidi, Davood Shahrjerdi
  • Publication number: 20150060760
    Abstract: A light-emitting diode device includes a base substrate including a plurality of quantum well layers, a first electrode on one side of the plurality of quantum well layers, and a second electrode on an opposite side of the plurality of quantum well layers. The device includes a tensile-stressing layer formed on the base substrate and having a thickness and chemical composition configured to generate a first tensile stress in the base substrate, the first compressive stress selected to cause the base substrate to have a predetermined band-gap.
    Type: Application
    Filed: October 21, 2013
    Publication date: March 5, 2015
    Applicant: International Business Machines Corporation
    Inventors: Stephen W. Bedell, Bahman Hekmatshoartabari, Devendra K. Sadana, Davood Shahrjerdi
  • Publication number: 20150060759
    Abstract: A method of forming a light-emitting diode including determining a first level of tensile stress to be applied to a base substrate including a plurality of quantum well layers to adjust a band-gap of the base substrate to a predetermined band-gap. The first level of tensile stress is generated in the base substrate by forming a tensile-stressing layer on the base substrate.
    Type: Application
    Filed: September 5, 2013
    Publication date: March 5, 2015
    Applicant: International Business Machines Corporation
    Inventors: Stephen W. Bedell, Bahman Hekmatshoartabari, Devendra K. Sadana, Davood Shahrjerdi
  • Publication number: 20150059841
    Abstract: A method for fabricating a photovoltaic device includes forming a patterned layer on a doped emitter portion of the photovoltaic device, the patterned layer including openings that expose areas of the doped emitter portion and growing an epitaxial layer over the patterned layer such that a crystalline phase grows in contact with the doped emitter portion and a non-crystalline phase grows in contact with the patterned layer. The non-crystalline phase is removed from the patterned layer. Conductive contacts are formed on the epitaxial layer in the openings to form a contact area for the photovoltaic device.
    Type: Application
    Filed: October 29, 2014
    Publication date: March 5, 2015
    Inventors: Bahman Hekmatshoartabari, Ali Khakifirooz, Devendra K. Sadana, Ghavam G. Shahidi, Davood Shahrjerdi
  • Patent number: 8969992
    Abstract: An autonomous integrated circuit (IC) includes a solar cell formed on a bottom substrate of a silicon-on-insulator (SOI) substrate as a handle substrate; an insulating layer of the SOI substrate located on top of the solar cell; and a device layer formed on a top semiconductor layer of the SOI substrate located on top of the insulating layer, wherein a top contact of the device layer is electrically connected to a bottom contact of the solar cell such that the solar cell is enabled to power the device layer.
    Type: Grant
    Filed: March 6, 2014
    Date of Patent: March 3, 2015
    Assignee: International Business Machines Corporation
    Inventors: Stephen W. Bedell, Norma E. Sosa Cortes, Wilfried E. Haensch, Steven J. Koester, Devendra K. Sadana, Katherine L. Saenger, Ghavam Shahidi, Davood Shahrjerdi
  • Patent number: 8969109
    Abstract: A method of forming a light-emitting diode including determining a first level of tensile stress to be applied to a base substrate including a plurality of quantum well layers to adjust a band-gap of the base substrate to a predetermined band-gap. The first level of tensile stress is generated in the base substrate by forming a tensile-stressing layer on the base substrate.
    Type: Grant
    Filed: September 5, 2013
    Date of Patent: March 3, 2015
    Assignee: International Business Machines Corporation
    Inventors: Stephen W. Bedell, Bahman Hekmatshoartabari, Devendra K. Sadana, Davood Shahrjerdi
  • Publication number: 20150050769
    Abstract: A solar-powered autonomous CMOS circuit structure is fabricated with monolithically integrated photovoltaic solar cells. The structure includes a device layer including an integrated circuit and a solar cell layer. Solar cell structures in the solar cell layer can be series connected during metallization of the device layer or subsequently. The device layer and the solar cell layer are formed using a silicon-on-insulator substrate. Subsequent spalling of the silicon-on-insulator substrate through the handle substrate thereof facilitates production of a relatively thin solar cell layer that can be subjected to a selective etching process to isolate the solar cell structures.
    Type: Application
    Filed: October 31, 2014
    Publication date: February 19, 2015
    Inventors: Stephen W. Bedell, Bahman Hekmatshoartabari, Devendra K. Sadana, Ghavam G. Shahidi, Davood Shahrjerdi
  • Publication number: 20150047704
    Abstract: Solar cell structures that have improved carrier collection efficiencies at a heterointerface are provided by low temperature epitaxial growth of silicon on a III-V base. Additionally, a solar cell structure having improved open circuit voltage includes a shallow junction III-V emitter formed by epitaxy or diffusion followed by the epitaxy of SixGe1?x passivated by amorphous SiyGe1?y:H.
    Type: Application
    Filed: September 29, 2014
    Publication date: February 19, 2015
    Inventors: Stephen W. Bedell, Bahman Hekmatshoartabari, Devendra K. Sadana, Davood Shahrjerdi
  • Publication number: 20150041756
    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: Application
    Filed: September 9, 2013
    Publication date: February 12, 2015
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Stephen W. Bedell, Bahman Hekmatshoartabari, Devendra K. Sadana, Davood Shahrjerdi
  • Publication number: 20150044796
    Abstract: A method for fabrication a light emitting diode (LED) includes forming alternating material layers on an LED structure, formed on a substrate, to form a reflector on a back side opposite the substrate. A handle substrate is adhered to a stressor layer deposited on the reflector. The LED structure is separated from the substrate using a spalling process to expose a front side of the LED structure.
    Type: Application
    Filed: September 19, 2014
    Publication date: February 12, 2015
    Inventors: Stephen W. Bedell, Bahman Hekmatshoartabari, Devendra K. Sadana, Davood Shahrjerdi
  • Publication number: 20150041938
    Abstract: A method for forming a back-illuminated image sensor includes forming a higher doped crystalline layer on a crystalline substrate, growing a lower doped crystalline layer on the higher doped crystalline layer and forming a photodiode and component circuitry from the lower doped crystalline layer. Metallization structures are formed to make connections to and between components. The crystalline substrate is removed to expose the higher doped crystalline layer. An optical component structure is provided on an exposed surface of the higher doped crystalline layer to receive light therein such that the higher doped crystalline layer provides a passivation layer for the photodiode and the component circuitry.
    Type: Application
    Filed: September 6, 2013
    Publication date: February 12, 2015
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Stephen W. Bedell, Bahman Hekmatshoartabari, Ghavam G. Shahidi, Davood Shahrjerdi
  • Publication number: 20150041826
    Abstract: A method for forming a semiconductor device includes forming a dielectric layer on a first substrate and wafer bonding the dielectric layer of the first substrate to a second substrate including SiC with a passivating layer formed on the SiC. A portion of the first substrate is removed from a side opposite the dielectric layer. The dielectric layer is patterned to form a gate dielectric for a field effect transistor formed on the second substrate.
    Type: Application
    Filed: September 6, 2013
    Publication date: February 12, 2015
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Bahman Hekmatshoartabari, Ali Khakifirooz, Ghavam G. Shahidi, Davood Shahrjerdi
  • Publication number: 20150041936
    Abstract: A method for forming a back-illuminated image sensor includes forming a higher doped crystalline layer on a crystalline substrate, growing a lower doped crystalline layer on the higher doped crystalline layer and forming a photodiode and component circuitry from the lower doped crystalline layer. Metallization structures are formed to make connections to and between components. The crystalline substrate is removed to expose the higher doped crystalline layer. An optical component structure is provided on an exposed surface of the higher doped crystalline layer to receive light therein such that the higher doped crystalline layer provides a passivation layer for the photodiode and the component circuitry.
    Type: Application
    Filed: August 7, 2013
    Publication date: February 12, 2015
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Stephen W. Bedell, Bahman Hekmatshoartabari, Ghavam G. Shahidi, Davood Shahrjerdi
  • Publication number: 20150041824
    Abstract: A method for forming a semiconductor device includes forming a dielectric layer on a first substrate and wafer bonding the dielectric layer of the first substrate to a second substrate including SiC with a passivating layer formed on the SiC. A portion of the first substrate is removed from a side opposite the dielectric layer. The dielectric layer is patterned to form a gate dielectric for a field effect transistor formed on the second substrate.
    Type: Application
    Filed: August 7, 2013
    Publication date: February 12, 2015
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Bahman Hekmatshoartabari, Ali Khakifirooz, Ghavam G. Shahidi, Davood Shahrjerdi