Patents by Inventor Anirban Basu

Anirban Basu 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: 20140342485
    Abstract: A vertical stack including a p-doped GaN portion, a multi-quantum-well including indium gallium nitride layers, and an n-doped transparent conductive material portion is formed on an insulator substrate. A dielectric material liner is formed around the vertical stack, and is patterned to physically expose a surface of the p-doped GaN portion. A selective low temperature epitaxy process is employed to deposit a semiconductor material including at least one elemental semiconductor material on the physically exposed surfaces of the p-doped GaN portion, thereby forming an elemental semiconductor material portion. The selective low temperature epitaxy process can be performed at a temperature lower than 600° C., thereby limiting diffusion of materials within the multi-quantum well and avoiding segregation of indium within the multi-quantum well. The light-emitting diode can generate a radiation of a wide range including blue and green lights in the visible wavelength range.
    Type: Application
    Filed: September 6, 2013
    Publication date: November 20, 2014
    Applicant: International Business Machines Corporation
    Inventors: Anirban Basu, Wilfried Haensch, Bahman Hekmatshoartabari, Davood Shahrjerdi
  • Publication number: 20140335665
    Abstract: A gate stack including a gate dielectric and a gate electrode is formed over at least one compound semiconductor fin provided on an insulating substrate. The at least one compound semiconductor fin is thinned employing the gate stack as an etch mask. Source/drain extension regions are epitaxially deposited on physically exposed surfaces of the at least one semiconductor fin. A gate spacer is formed around the gate stack. A raised source region and a raised drain region are epitaxially formed on the source/drain extension regions. The source/drain extension regions are self-aligned to sidewalls of the gate stack, and thus ensure a sufficient overlap with the gate electrode. Further, the combination of the source/drain extension regions and the raised source/drain regions provides a low-resistance path to the channel of the field effect transistor.
    Type: Application
    Filed: September 9, 2013
    Publication date: November 13, 2014
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Anirban Basu, Pouya Hashemi
  • Publication number: 20140332900
    Abstract: A gate stack including a gate dielectric and a gate electrode is formed over at least one compound semiconductor fin provided on an insulating substrate. The at least one compound semiconductor fin is thinned employing the gate stack as an etch mask. Source/drain extension regions are epitaxially deposited on physically exposed surfaces of the at least one semiconductor fin. A gate spacer is formed around the gate stack. A raised source region and a raised drain region are epitaxially formed on the source/drain extension regions. The source/drain extension regions are self-aligned to sidewalls of the gate stack, and thus ensure a sufficient overlap with the gate electrode. Further, the combination of the source/drain extension regions and the raised source/drain regions provides a low-resistance path to the channel of the field effect transistor.
    Type: Application
    Filed: May 8, 2013
    Publication date: November 13, 2014
    Applicant: International Business Machines Corporation
    Inventors: Anirban Basu, Pouya Hashemi
  • Patent number: 8877574
    Abstract: Portions of a top compound semiconductor layer are recessed employing a gate electrode as an etch mask to form a source trench and a drain trench. A low temperature epitaxy process is employed to deposit a semiconductor material including at least one elemental semiconductor material in the source trench and the drain trench. Metallization is performed on physically exposed surfaces of the elemental semiconductor material portions in the source trench and the drain trench by depositing a metal and inducing interaction with the metal and the at least one elemental semiconductor material. A metal semiconductor alloy of the metal and the at least one elemental semiconductor material can be performed at a temperature lower than 600° C. to provide a high electron mobility transistor with a well-defined device profile and reliable metallization contacts.
    Type: Grant
    Filed: September 6, 2013
    Date of Patent: November 4, 2014
    Assignee: International Business Machines Corporation
    Inventors: Anirban Basu, Bahman Hekmatshoartabari, Davood Shahrjerdi
  • Publication number: 20140264607
    Abstract: A method for forming fin field effect transistors includes forming a dielectric layer on a silicon substrate, forming high aspect ratio trenches in the dielectric layer down to the substrate, the high aspect ratio including a height to width ratio of greater than about 1:1 and epitaxially growing a non-silicon containing semiconductor material in the trenches using an aspect ratio trapping process to form fins. The one or more dielectric layers are etched to expose a portion of the fins. A barrier layer is epitaxially grown on the portion of the fins, and a gate stack is formed over the fins. A spacer is formed around the portion of the fins and the gate stack. Dopants are implanted into the portion of the fins. Source and drain regions are grown over the fins using a non-silicon containing semiconductor material.
    Type: Application
    Filed: March 13, 2013
    Publication date: September 18, 2014
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Anirban Basu, Cheng-Wei Cheng, Amlan Majumdar, Ryan M. Martin, Uzma Rana, Devendra K. Sadana, Kuen-Ting Shiu, Yanning Sun
  • Publication number: 20140264446
    Abstract: A method for forming fin field effect transistors includes forming a dielectric layer on a silicon substrate, forming high aspect ratio trenches in the dielectric layer down to the substrate, the high aspect ratio including a height to width ratio of greater than about 1:1 and epitaxially growing a non-silicon containing semiconductor material in the trenches using an aspect ratio trapping process to form fins. The one or more dielectric layers are etched to expose a portion of the fins. A barrier layer is epitaxially grown on the portion of the fins, and a gate stack is formed over the fins. A spacer is formed around the portion of the fins and the gate stack. Dopants are implanted into the portion of the fins. Source and drain regions are grown over the fins using a non-silicon containing semiconductor material.
    Type: Application
    Filed: August 14, 2013
    Publication date: September 18, 2014
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: ANIRBAN BASU, CHENG-WEI CHENG, AMLAN MAJUMDAR, RYAN M. MARTIN, UZMA RANA, DEVENDRA K. SADANA, KUEN-TING SHIU, YANNING SUN
  • Publication number: 20140151757
    Abstract: Single crystalline semiconductor fins are formed on a single crystalline buried insulator layer. After formation of a gate electrode straddling the single crystalline semiconductor fins, selective epitaxy can be performed with a semiconductor material that grows on the single crystalline buried insulator layer to form a contiguous semiconductor material portion. The thickness of the deposited semiconductor material in the contiguous semiconductor material portion can be selected such that sidewalls of the deposited semiconductor material portions do not merge, but are conductively connected to one another via horizontal portions of the deposited semiconductor material that grow directly on a horizontal surface of the single crystalline buried insulator layer. Simultaneous reduction in the contact resistance and parasitic capacitance for a fin field effect transistor can be provided through the contiguous semiconductor material portion and cylindrical contact via structures.
    Type: Application
    Filed: December 3, 2012
    Publication date: June 5, 2014
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Anirban Basu, Josephine B. Chang, Michael A. Guillorn, Amlan Majumdar
  • Publication number: 20140131287
    Abstract: Disinfecting a sample of water includes generating a current using an array of photovoltaic cells, using the current to power an array of light emitting diodes, wherein the array of light emitting diodes emits a germicidal wavelength of radiation, and exposing the sample of water to the radiation. Another method for disinfecting a sample of water includes placing the sample of water within a container, wherein the container includes an array of photovoltaic cells encircling an exterior wall of the container and an array of light emitting diodes encircling an interior wall of the container, placing the container in a location exposed to solar radiation, converting the solar radiation to a current using the array of photovoltaic cells, and powering the array of light emitting diodes using the current, wherein the array of light emitting diodes emits a germicidal wavelength of radiation sufficient to disinfect the sample of water.
    Type: Application
    Filed: November 9, 2012
    Publication date: May 15, 2014
    Applicant: International Business Machines Corporation
    Inventors: ANIRBAN BASU, Stephen W. Bedell, Devendra K. Sadana
  • Publication number: 20140131591
    Abstract: A system for disinfecting a sample of water includes a container for holding the sample of water, an array of photovoltaic cells coupled to the container for converting solar radiation into a current, and an array of light emitting diodes coupled to the container and powered by the current, wherein the array of light emitting diodes emits a germicidal wavelength of radiation. Another system for disinfecting a sample of water includes a container for holding the sample of water, an array of photovoltaic cells encircling an exterior wall of the container, for converting solar radiation into a current, and an array of light emitting diodes encircling an interior wall of the container and powered by the current, wherein the array of light emitting diodes emits a germicidal wavelength of radiation.
    Type: Application
    Filed: August 19, 2013
    Publication date: May 15, 2014
    Applicant: International Business Machines Corporation
    Inventors: ANIRBAN BASU, Stephen W. Bedell, Devendra K. Sadana
  • Publication number: 20140131286
    Abstract: A system for disinfecting a water sample includes a pipe having an inlet for engaging a source of the water sample, a storage reservoir connected to an outlet of the pipe for holding the water sample, an array of photovoltaic cells coupled to the pipe for converting solar radiation into a current, and an array of light emitting diodes coupled to the pipe and powered by the current, wherein the array of light emitting diodes emits a germicidal wavelength of radiation. A method for disinfecting a fluent water sample includes generating a current using an array of photovoltaic cells, using the current to power an array of light emitting diodes, wherein the array of light emitting diodes emits a germicidal wavelength of radiation, and exposing the fluent water sample to the radiation while transporting the fluent water sample from a source to a storage reservoir.
    Type: Application
    Filed: February 1, 2013
    Publication date: May 15, 2014
    Applicant: International Business Machines Corporation
    Inventors: Anirban Basu, Stephen W. Bedell, Wilfried E. Haensch, Davood Shahrjerdi