Patents by Inventor Bhupesh Chandra
Bhupesh Chandra 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).
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Publication number: 20150302950Abstract: Transparent conducting electrodes include a doped single walled carbon nanotube film and methods for forming the doped single walled carbon nanotube (SWCNT) by solution processing. The method generally includes depositing single walled carbon nanotubes dispersed in a solvent and a surfactant onto a substrate to form a single walled carbon nanotube film thereon; removing all of the surfactant from the carbon nanotube film; and exposing the single walled carbon nanotube film to a single electron oxidant in a solution such that one electron is transferred from the single walled carbon nanotubes to each molecule of the single electron oxidant.Type: ApplicationFiled: June 29, 2015Publication date: October 22, 2015Inventors: Mostafa M. El-Ashry, Ali Afzali-Ardakani, Bhupesh Chandra, George S. Tulevski
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Patent number: 9162883Abstract: Transparent conducting electrodes include a doped single walled carbon nanotube film and methods for forming the doped single walled carbon nanotube (SWCNT) by solution processing. The method generally includes depositing single walled carbon nanotubes dispersed in a solvent and a surfactant onto a substrate to form a single walled carbon nanotube film thereon; removing all of the surfactant from the carbon nanotube film; and exposing the single walled carbon nanotube film to a single electron oxidant in a solution such that one electron is transferred from the single walled carbon nanotubes to each molecule of the single electron oxidant.Type: GrantFiled: September 1, 2010Date of Patent: October 20, 2015Assignees: International Business Machines Corporation, EGYPT NANOTECHNOLOGY CENTERInventors: Mostafa M. El-Ashry, Ali Afzali-Ardakani, Bhupesh Chandra, George S. Tulevski
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Patent number: 9105853Abstract: A composition and method for forming a field effect transistor with a stable n-doped nano-component. The method includes forming a gate dielectric on a gate, forming a channel comprising a nano-component on the gate dielectric, forming a source over a first region of the nano-component, forming a drain over a second region of the nano-component to form a field effect transistor, and exposing a portion of a nano-component of a field effect transistor to dihydrotetraazapentacene, wherein dihydrotetraazapentacene is represented by the formula: wherein each of R1, R2, R3, and R4 comprises one of hydrogen, an alkyl group of C1 to C16 carbons, an alkoxy group, an alkylthio group, a trialkylsilane group, a hydroxymethyl group, a carboxylic acid group and a carboxylic ester group.Type: GrantFiled: October 11, 2013Date of Patent: August 11, 2015Assignee: International Business Machines CorporationInventors: Ali Afzali-Ardakani, Bhupesh Chandra, George Stojan Tulevski
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Patent number: 9017813Abstract: Transparent conducting electrodes include a doped single walled carbon nanotube film and methods for forming the doped single walled carbon nanotube (SWCNT) by solution processing. The method generally includes depositing single walled carbon nanotubes dispersed in a solvent and a surfactant onto a substrate to form a single walled carbon nanotube film thereon; removing all of the surfactant from the carbon nanotube film; and exposing the single walled carbon nanotube film to a single electron oxidant in a solution such that one electron is transferred from the single walled carbon nanotubes to each molecule of the single electron oxidant.Type: GrantFiled: July 18, 2012Date of Patent: April 28, 2015Assignees: International Business Machines Corporation, Egypt Nanotechnology CenterInventors: Mostafa M. El-Ashry, Ali Afzali-Ardakani, Bhupesh Chandra, George S. Tulevski
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Publication number: 20150084096Abstract: A faceted intrinsic buffer semiconductor material is deposited on sidewalls of a source trench and a drain trench by selective epitaxy. A facet adjoins each edge at which an outer sidewall of a gate spacer adjoins a sidewall of the source trench or the drain trench. A doped semiconductor material is subsequently deposited to fill the source trench and the drain trench. The doped semiconductor material can be deposited such that the facets of the intrinsic buffer semiconductor material are extended and inner sidewalls of the deposited doped semiconductor material merges in each of the source trench and the drain trench. The doped semiconductor material can subsequently grow upward. Faceted intrinsic buffer semiconductor material portions allow greater outdiffusion of dopants near faceted corners while suppressing diffusion of dopants in regions of uniform width, thereby suppressing short channel effects.Type: ApplicationFiled: October 7, 2014Publication date: March 26, 2015Inventors: Bhupesh Chandra, Paul Chang, Gregory G. Freeman, Dechao Guo, Judson R. Holt, Arvind Kumar, Timothy J. McArdle, Shreesh Narasimha, Viorel Ontalus, Sangameshwar Saudari, Christopher D. Sheraw, Matthew W. Stoker
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Patent number: 8940595Abstract: A faceted intrinsic buffer semiconductor material is deposited on sidewalls of a source trench and a drain trench by selective epitaxy. A facet adjoins each edge at which an outer sidewall of a gate spacer adjoins a sidewall of the source trench or the drain trench. A doped semiconductor material is subsequently deposited to fill the source trench and the drain trench. The doped semiconductor material can be deposited such that the facets of the intrinsic buffer semiconductor material are extended and inner sidewalls of the deposited doped semiconductor material merges in each of the source trench and the drain trench. The doped semiconductor material can subsequently grow upward. Faceted intrinsic buffer semiconductor material portions allow greater outdiffusion of dopants near faceted corners while suppressing diffusion of dopants in regions of uniform width, thereby suppressing short channel effects.Type: GrantFiled: March 15, 2013Date of Patent: January 27, 2015Assignee: International Business Machines CorporationInventors: Bhupesh Chandra, Paul Chang, Gregory G. Freeman, Dechao Guo, Judson R. Holt, Arvind Kumar, Timothy J. McArdle, Shreesh Narasimha, Viorel Ontalus, Sangameshwar Rao Saudari, Christopher D. Sheraw, Matthew W. Stoker
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Patent number: 8912525Abstract: A process comprises combining a Ce (IV) salt with a carbon material comprising CNT or graphene wherein the Ce (IV) salt is selected from a Ce (IV) ammonium salt of a nitrogen oxide acid and is dissolved in a solvent comprising water. The process is conducted under conditions to substantially oxidize the carbon material to produce an oxidized material that is substantially non-conducting. After the oxidation, the Ce (IV) is substantially removed from the oxidized material. This produces a product made by the process. An article of manufacture comprises the product on a substrate. The oxidized material can be formed as a pattern on the substrate. In another embodiment the substrate comprises an electronic device with the oxidized material patterning non-conductive areas separate from conductive areas of the non-oxidized carbon material, where the conductive areas are operatively associated with the device.Type: GrantFiled: December 16, 2011Date of Patent: December 16, 2014Assignee: International Business Machines CorporationInventors: Ali Afzali-Ardakani, Bhupesh Chandra, George S. Tulevski
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Patent number: 8895417Abstract: A method and an apparatus for doping at least one of a graphene and a nanotube thin-film transistor field-effect transistor device to decrease contact resistance with a metal electrode. The method includes selectively applying a dopant to a metal contact region of at least one of a graphene and a nanotube field-effect transistor device to decrease the contact resistance of the field-effect transistor device.Type: GrantFiled: November 29, 2011Date of Patent: November 25, 2014Assignee: International Business Machines CorporationInventors: Ali Afzali-Ardakani, Bhupesh Chandra, George Stojan Tulevski, Fengnian Xia
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Publication number: 20140264558Abstract: A faceted intrinsic buffer semiconductor material is deposited on sidewalls of a source trench and a drain trench by selective epitaxy. A facet adjoins each edge at which an outer sidewall of a gate spacer adjoins a sidewall of the source trench or the drain trench. A doped semiconductor material is subsequently deposited to fill the source trench and the drain trench. The doped semiconductor material can be deposited such that the facets of the intrinsic buffer semiconductor material are extended and inner sidewalls of the deposited doped semiconductor material merges in each of the source trench and the drain trench. The doped semiconductor material can subsequently grow upward. Faceted intrinsic buffer semiconductor material portions allow greater outdiffusion of dopants near faceted corners while suppressing diffusion of dopants in regions of uniform width, thereby suppressing short channel effects.Type: ApplicationFiled: March 15, 2013Publication date: September 18, 2014Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Bhupesh Chandra, Paul Chang, Gregory G. Freeman, Dechao Guo, Judson R. Holt, Arvind Kumar, Timothy J. McArdle, Shreesh Narasimha, Viorel Ontalus, Sangameshwar Rao Saudari, Christopher D. Sheraw, Matthew W. Stoker
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Patent number: 8772141Abstract: A method for doping a graphene or nanotube thin-film field-effect transistor device to improve electronic mobility. The method includes selectively applying a dopant to a channel region of a graphene or nanotube thin-film field-effect transistor device to improve electronic mobility of the field-effect transistor device.Type: GrantFiled: September 26, 2012Date of Patent: July 8, 2014Assignee: International Business Machines CorporationInventors: Ali Afzali-Ardakani, Bhupesh Chandra, George Stojan Tulevski
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Patent number: 8772910Abstract: A method and an apparatus for doping a graphene or nanotube thin-film field-effect transistor device to improve electronic mobility. The method includes selectively applying a dopant to a channel region of a graphene or nanotube thin-film field-effect transistor device to improve electronic mobility of the field-effect transistor device.Type: GrantFiled: November 29, 2011Date of Patent: July 8, 2014Assignee: International Business Machines CorporationInventors: Ali Afzali-Ardakani, Bhupesh Chandra, George Stojan Tulevski
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Publication number: 20140038350Abstract: A composition and method for forming a field effect transistor with a stable n-doped nano-component. The method includes forming a gate dielectric on a gate, forming a channel comprising a nano-component on the gate dielectric, forming a source over a first region of the nano-component, forming a drain over a second region of the nano-component to form a field effect transistor, and exposing a portion of a nano-component of a field effect transistor to dihydrotetraazapentacene, wherein dihydrotetraazapentacene is represented by the formula: wherein each of R1, R2, R3, and R4 comprises one of hydrogen, an alkyl group of C1 to C16 carbons, an alkoxy group, an alkylthio group, a trialkylsilane group, a hydroxymethyl group, a carboxylic acid group and a carboxylic ester group.Type: ApplicationFiled: October 11, 2013Publication date: February 6, 2014Applicant: International Business Machines CorporationInventors: Ali Afzali-Ardakani, Bhupesh Chandra, George Stojan Tulevski
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Patent number: 8642432Abstract: A composition and method for forming a field effect transistor with a stable n-doped nano-component. The method includes forming a gate dielectric on a gate, forming a channel comprising a nano-component on the gate dielectric, forming a source over a first region of the nano-component, forming a drain over a second region of the nano-component to form a field effect transistor, and exposing a portion of a nano-component of a field effect transistor to dihydrotetraazapentacene to produce a stable n-doped nano-component, wherein dihydrotetraazapentacene is represented by the formula: wherein in the dihydrotetraazapentacene chemical structure, each of R1, R2, R3, and R4 can be hydrogen, an alkyl group of C1 to C16 carbons, an alkoxy group, an alkylthio group, a trialkylsilane group, a hydroxymethyl group, a carboxylic acid group or a carboxylic ester group.Type: GrantFiled: December 1, 2011Date of Patent: February 4, 2014Assignee: International Business Machines CorporationInventors: Ali Afzali-Ardakani, Bhupesh Chandra, George Stojan Tulevski
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Publication number: 20130153855Abstract: A process comprises combining a Ce (IV) salt with a carbon material comprising CNT or graphene wherein the Ce (IV) salt is selected from a Ce (IV) ammonium salt of a nitrogen oxide acid and is dissolved in a solvent comprising water. The process is conducted under conditions to substantially oxidize the carbon material to produce an oxidized material that is substantially non-conducting. After the oxidation, the Ce (IV) is substantially removed from the oxidized material. This produces a product made by the process. An article of manufacture comprises the product on a substrate. The oxidized material can be formed as a pattern on the substrate. In another embodiment the substrate comprises an electronic device with the oxidized material patterning non-conductive areas separate from conductive areas of the non-oxidized carbon material, where the conductive areas are operatively associated with the device.Type: ApplicationFiled: December 16, 2011Publication date: June 20, 2013Applicant: International Business Machines CorporationInventors: Ali Afzali-Ardakani, Bhupesh Chandra, George S. Tulevski
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Publication number: 20130153831Abstract: A process comprises combining a Ce (IV) salt dissolved in a solvent comprising water with a carbon material comprising CNT or graphene wherein the Ce (IV) salt is selected from a Ce (IV) ammonium salt of a nitrogen oxide acid, Ce (IV) ammonium salt of a sulfur oxide acid, Ce (IV) salt of a lower alkyl organo sulfur acid, or Ce (IV) salt of a lower alkane organo sulfur acid. In one embodiment the Ce (IV) salt is selected from Ce (IV) ammonium nitrate, Ce (IV) ammonium sulfate, Ce (IV) lower alkyllsulfonate, or Ce (IV) trifluoro lower alkanesulfonate. A product is produced by this process. An article of manufacture comprises this product on a substrate.Type: ApplicationFiled: December 16, 2011Publication date: June 20, 2013Applicant: International Business Machines CorporationInventors: Ali Afzali-Ardakani, Bhupesh Chandra, George S. Tulevski
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Publication number: 20130143356Abstract: A composition and method for forming a field effect transistor with a stable n-doped nano-component. The method includes forming a gate dielectric on a gate, forming a channel comprising a nano-component on the gate dielectric, forming a source over a first region of the nano-component, forming a drain over a second region of the nano-component to form a field effect transistor, and exposing a portion of a nano-component of a field effect transistor to dihydrotetraazapentacene to produce a stable n-doped nano-component, wherein dihydrotetraazapentacene is represented by the formula: wherein in the dihydrotetraazapentacene chemical structure, each of R1, R2, R3, and R4 can be hydrogen, an alkyl group of C1 to C16 carbons, an alkoxy group, an alkylthio group, a trialkylsilane group, a hydroxymethyl group, a carboxylic acid group or a carboxylic ester group.Type: ApplicationFiled: December 1, 2011Publication date: June 6, 2013Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Ali Afzali-Ardakani, Bhupesh Chandra, George S. Tulevski
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Publication number: 20130134391Abstract: A method and an apparatus for doping a graphene and nanotube thin-film transistor field-effect transistor device to decrease contact resistance with a metal electrode. The method includes selectively applying a dopant to a metal contact region of a graphene and nanotube field-effect transistor device to decrease the contact resistance of the field-effect transistor device.Type: ApplicationFiled: November 29, 2011Publication date: May 30, 2013Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Ali Afzali-Ardakani, Bhupesh Chandra, George S. Tulevski, Fengnian Xia
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Publication number: 20130134392Abstract: A method and an apparatus for doping a graphene or nanotube thin-film field-effect transistor device to improve electronic mobility. The method includes selectively applying a dopant to a channel region of a graphene or nanotube thin-film field-effect transistor device to improve electronic mobility of the field-effect transistor device.Type: ApplicationFiled: November 29, 2011Publication date: May 30, 2013Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Ali Afzali-Ardakani, Bhupesh Chandra, George S. Tulevski
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Publication number: 20130130037Abstract: A nanotube-graphene hybrid film and method for forming a cleaned nanotube-graphene hybrid film. The method includes depositing nanotube film over a substrate to produce a layer of nanotube film, removing impurities from a surface of the layer of nanotube film not contacting the substrate to produce a cleaned layer of nanotube film, depositing a layer of graphene over the cleaned layer of nanotube film to produce a nanotube-graphene hybrid film, and removing impurities from a surface of the nanotube-graphene hybrid film to produce a cleaned nanotube-graphene hybrid film, wherein the hybrid film has improved electrical performance. Another method includes depositing nanotube film over a metal foil to produce a layer of nanotube film, placing the metal foil with as-deposited nanotube film in a chemical vapor deposition furnace to grow graphene on the nanotube film to form a nanotube-graphene hybrid film, and transferring the nanotube-graphene hybrid film over a substrate.Type: ApplicationFiled: November 22, 2011Publication date: May 23, 2013Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Ageeth A. Bol, Bhupesh Chandra, Amal Kasry, Ahmed Maarouf, Glenn J. Martyna, George S. Tulevski
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Publication number: 20130025662Abstract: Techniques for reducing the resistivity of carbon nanotube and graphene materials are provided. In one aspect, a method of producing a doped carbon film having reduced resistivity is provided. The method includes the following steps. A carbon material selected from the group consisting of: a nanotube, graphene, fullerene and pentacene is provided. The carbon material and a dopant solution comprising an oxidized form of ruthenium bipyridyl are contacted, wherein the contacting is carried out under conditions sufficient to produce the doped carbon film having reduced resistivity.Type: ApplicationFiled: July 25, 2011Publication date: January 31, 2013Applicant: International Business Machines CorporationInventors: Ali Afzali-Ardakani, Ageeth Anke Bol, Bhupesh Chandra, George Stojan Tulevski