Patents by Inventor Shreesh Narasimha
Shreesh Narasimha 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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Patent number: 7818693Abstract: A system and method for modeling a semiconductor transistor device structure having a conductive line feature of a designed length connected to a gate of a transistor device in a circuit to be modeled, the transistor including an active device (RX) area over which the gate is formed and over which the conductive line feature extends. The method includes providing an analytical model representation including a function for modeling a lithographic flare effect impacting the active device area width; and, from the modeling function, relating an effective change in active device area width (deltaW adder) as a function of a distance from a defined edge of the RX area. Then, transistor model parameter values in a transistor compact model for the device are updated to include deltaW adder values to be added to a built-in deltaW value.Type: GrantFiled: January 8, 2008Date of Patent: October 19, 2010Assignee: International Business Machines CorporationInventors: Dureseti Chidambarrao, Gerald M. Davidson, Paul A. Hyde, Judith H. McCullen, Shreesh Narasimha
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Patent number: 7814454Abstract: A system, method and program product that allows multiple devices to be placed between pads such that a Back End Of Line (BEOL) mask change can be used to select different device options. A system is disclosed for implementing a testsite for characterizing devices in an integrated circuit technology, and includes: a system for designing a plurality of device options for a set of chip pads; a system for designing a pseudo wiring layout for each of the plurality of device options; a system for selecting one of the device options; a system for mapping the pseudo wiring layout for a selected device option to a predetermined design level; and a system for outputting a configured mask design at the predetermined design level having a wiring layout mapped for the selected device option.Type: GrantFiled: June 28, 2007Date of Patent: October 12, 2010Assignee: International Business Machines CorporationInventors: Anthony I. Chou, James S. Dunn, Brian M. Dufrene, Christopher H. Lumbra, Shreesh Narasimha, Christopher S. Putnam, BethAnn Rainey, Christopher M. Schnabel
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Patent number: 7804140Abstract: Edges of source and drain regions along the direction of a channel of a field effect transistor are formed within an active area offset from the boundary between the active area and a shallow trench isolation structure. Such a structure may be manufactured by forming a gate electrode structure that overlies the boundary so that edges of the source and drain regions are self aligned to the edges of the gate electrode structure on the active area side of the boundary. Unnecessary portions of the gate electrode that does not overlie the source and drain regions may be removed to reduce parasitic capacitance. Shallow trench isolation edge current is eliminated since the semiconductor regions in the current path of the field effect transistor are offset from the boundary between the active area and the shallow trench isolation structure.Type: GrantFiled: March 4, 2008Date of Patent: September 28, 2010Assignee: International Business Machines CorporationInventors: Leland Chang, Anthony I. Chou, Shreesh Narasimha, Jeffrey W. Sleight
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Publication number: 20100237421Abstract: A gated diode structure and a method for fabricating the gated diode structure use a relaxed liner that is derived from a stressed liner that is typically used within the context of a field effect transistor formed simultaneously with the gated diode structure. The relaxed liner is formed incident to treatment, such as ion implantation treatment, of the stressed liner. The relaxed liner provides improved gated diode ideality in comparison with the stressed liner, absent any gated diode damage that may occur incident to stripping the stressed liner from the gated diode structure while using a reactive ion etch method.Type: ApplicationFiled: February 9, 2010Publication date: September 23, 2010Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Anthony I. Chou, Gregory G. Freeman, Kevin McStay, Shreesh Narasimha
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Patent number: 7776695Abstract: A method for making a semiconductor device structure, includes: providing a substrate; forming on the substrate a first gate with first spacers, a second gate with second spacers, respective source and drain regions of a same conductive type adjacent to the first gate and the second gate, an isolation region disposed intermediate of the first gate and the second gate, silicides on the first gate, the second gate and respective source and drain regions; forming additional spacers on the first spacers to produce an intermediate structure, and then disposing a stress layer over the entire intermediate structure.Type: GrantFiled: January 9, 2006Date of Patent: August 17, 2010Assignee: International Business Machines CorporationInventors: John C. Arnold, Dureseti Chidambarrao, Ying Li, Rajeev Malik, Shreesh Narasimha, Siddhartha Panda, Brian L. Tessier, Richard Wise
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Publication number: 20100197118Abstract: A semiconductor structure includes an epitaxial surface semiconductor layer having a first dopant polarity and a first crystallographic orientation, and a laterally adjacent semiconductor-on-insulator surface semiconductor layer having a different second dopant polarity and different second crystallographic orientation. The epitaxial surface semiconductor layer has a first edge that has a defect and an adjoining second edge absent a defect. Located within the epitaxial surface semiconductor layer is a first device having a first gate perpendicular to the first edge and a second device having a second gate perpendicular to the second edge. The first device may include a performance sensitive logic device and the second device may include a yield sensitive memory device.Type: ApplicationFiled: April 9, 2010Publication date: August 5, 2010Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Shreesh Narasimha, Paul David Agnello, Xiaomeng Chen, Judson R. Holt, Mukesh Vijay Khare, Byeong Y. Kim, Devendra K. Sadana
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Patent number: 7767579Abstract: A method of making a semiconductor device includes forming a transistor structure having one of an embedded epitaxial stressed material in a source and drain region and a stressed channel and well, subjecting the transistor structure to plasma oxidation, and removing spacer material from the transistor structure.Type: GrantFiled: December 12, 2007Date of Patent: August 3, 2010Assignee: International Business Machines CorporationInventors: Ashima B Chakravarti, Zhijiong Luo, Renee Tong Mo, Shreesh Narasimha, Katsunori Onishi
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Publication number: 20100159684Abstract: A hybrid orientation technology (HOT) CMOS structure is comprised of a tensile stressed NFET gate stack and a compressively stressed PFET gate stack, where each gate stack is comprised of a high dielectric constant oxide/metal, and where the source of the stress in the tensile stressed NFET gate stack and the compressively stressed PFET gate stack is the metal in the high-k metal gate stack.Type: ApplicationFiled: February 17, 2010Publication date: June 24, 2010Inventors: Leland Chang, Shreesh Narasimha, Vijay Narayanan, Jeffrey W. Sleight
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Patent number: 7732270Abstract: The present invention provides a semiconductor device having dual nitride liners, which provide an increased transverse stress state for at least one FET and methods for the manufacture of such a device. A first aspect of the invention provides a method for use in the manufacture of a semiconductor device comprising the steps of applying a first silicon nitride liner to the device and applying a second silicon nitride liner adjacent the first silicon nitride liner, wherein at least one of the first and second silicon nitride liners induces a transverse stress in a silicon channel beneath at least one of the first and second silicon nitride liner.Type: GrantFiled: January 11, 2008Date of Patent: June 8, 2010Assignee: International Business Machines CorporationInventors: Dureseti Chidambarrao, Ying Li, Rajeev Malik, Shreesh Narasimha, Haining Yang, Huilong Zhu
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Patent number: 7714358Abstract: Disclosed are embodiments of an n-FET structure with silicon carbon S/D regions completely contained inside amorphization regions and with a carbon-free gate electrode. Containing carbon within the amorphization regions, ensures that all of the carbon is substitutional following re-crystallization to maximize the tensile stress imparted on channel region. The gate stack is capped during carbon implantation so the risk of carbon entering the gate stack and degrading the conductivity of the gate polysilicon and/or damaging the gate oxide is essentially eliminated. Thus, the carbon implant regions can be formed deeper. Deeper S/D carbon implants which are completely amorphized and then re-crystallized provide greater tensile stress on the n-FET channel region to further optimize electron mobility. Additionally, the gate electrode is uncapped during the n-type dopant process, so the n-type dopant dose in the gate electrode can be at least great as the dose in the S/D regions.Type: GrantFiled: February 8, 2007Date of Patent: May 11, 2010Assignee: International Business Machines CorporationInventors: Yaocheng Liu, Shreesh Narasimha, Katsunori Onishi, Kern Rim
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Patent number: 7713807Abstract: An integrated semiconductor structure containing at least one device formed upon a first crystallographic surface that is optimal for that device, while another device is formed upon a second different crystallographic surface that is optimal for the other device is provided. The method of forming the integrated structure includes providing a bonded substrate including at least a first semiconductor layer of a first crystallographic orientation and a second semiconductor layer of a second different crystallographic orientation. A portion of the bonded substrate is protected to define a first device area, while another portion of the bonded substrate is unprotected. The unprotected portion of the bonded substrate is then etched to expose a surface of the second semiconductor layer and a semiconductor material is regrown on the exposed surface. Following planarization, a first semiconductor device is formed in the first device region and a second semiconductor device is formed on the regrown material.Type: GrantFiled: December 18, 2007Date of Patent: May 11, 2010Assignee: International Business Machines CorporationInventors: Bruce B. Doris, Kathryn W. Guarini, Meikei Ieong, Shreesh Narasimha, Kern Rim, Jeffrey W. Sleight, Min Yang
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Publication number: 20100112766Abstract: Disclosed are embodiments of an n-FET structure with silicon carbon S/D regions completely contained inside amorphization regions and with a carbon-free gate electrode. Containing carbon within the amorphization regions, ensures that all of the carbon is substitutional following re-crystallization to maximize the tensile stress imparted on channel region. The gate stack is capped during carbon implantation so the risk of carbon entering the gate stack and degrading the conductivity of the gate polysilicon and/or damaging the gate oxide is essentially eliminated. Thus, the carbon implant regions can be formed deeper. Deeper S/D carbon implants which are completely amorphized and then re-crystallized provide greater tensile stress on the n-FET channel region to further optimize electron mobility. Additionally, the gate electrode is uncapped during the n-type dopant process, so the n-type dopant dose in the gate electrode can be at least great as the dose in the S/D regions.Type: ApplicationFiled: January 11, 2010Publication date: May 6, 2010Applicant: International Business Machines CorporationInventors: Yaocheng Liu, Shreesh Narasimha, Katsunori Onishi, Kern Rim
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Patent number: 7709910Abstract: A semiconductor structure provides lower parasitic capacitance between the gate electrode and contact vias while providing substantially the same level of stress applied by a nitride liner as conventional MOSFETs by reducing the height of the gate electrode and maintaining substantially the same height for the gate spacer. The nitride liner contacts only the outer sidewalls of the gate spacer, while not contacting inner sidewalls, or only a small area of the inner sidewalls of the gate spacer, therefore applying substantially the same level of stress to the channel of the MOSFET as conventional MOSFETs. The volume surrounded by the gate spacer and located above the gate electrode is either filled with a low-k dielectric material or occupied by a cavity having a dielectric constant of substantially 1.0. The reduced height of the gate electrode and the low-k dielectric gate filler or the cavity reduces the parasitic capacitance.Type: GrantFiled: April 23, 2007Date of Patent: May 4, 2010Assignee: International Business Machines CorporationInventors: William K. Henson, Paul Chung-Muh Chang, Dureseti Chidambarrao, Ricardo A. Donaton, Yaocheng Liu, Shreesh Narasimha, Amanda L. Tessier
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Patent number: 7696573Abstract: A semiconductor structure includes an epitaxial surface semiconductor layer having a first dopant polarity and a first crystallographic orientation, and a laterally adjacent semiconductor-on-insulator surface semiconductor layer having a different second dopant polarity and different second crystallographic orientation. The epitaxial surface semiconductor layer has a first edge that has a defect and an adjoining second edge absent a defect. Located within the epitaxial surface semiconductor layer is a first device having a first gate perpendicular to the first edge and a second device having a second gate perpendicular to the second edge. The first device may include a performance sensitive logic device and the second device may include a yield sensitive memory device.Type: GrantFiled: October 31, 2007Date of Patent: April 13, 2010Assignee: International Business Machines CorporationInventors: Shreesh Narasimha, Paul David Agnello, Xiaomeng Chen, Judson R. Holt, Mukesh Vijay Khare, Byeong Y. Kim, Devandra K. Sadana
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Patent number: 7687338Abstract: Embodiments of the invention provide a method of forming embedded silicon germanium (eSiGe) in source and drain regions of a p-type field-effect-transistor (pFET) through a disposable spacer process; depositing a gap-filling layer directly on the eSiGe in the source and drain regions in a first process; depositing a layer of offset spacer material on top of the gap-filling layer in a second process different from the first process; etching the offset spacer material and the gap-filling layer, thus forming a set of offset spacers and exposing the eSiGe in the source and drain regions of the pFET; and finishing formation of the pFET.Type: GrantFiled: December 5, 2007Date of Patent: March 30, 2010Assignee: International Business Machines CorporationInventors: Sameer Jain, Shreesh Narasimha, Karen A. Nummy, Viorel Ontalus, Jang H. Sim
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Publication number: 20090315138Abstract: In one embodiment, the present invention provides a semiconductor device that includes a substrate including a semiconducting layer positioned overlying an insulating layer the semiconducting layer including a semiconducting body and isolation regions present about a perimeter of the semiconducting body; a gate structure overlying the semiconducting layer of the substrate, the gate structure present on a first portion on an upper surface of the semiconducting body; and a silicide body contact that is in direct physical contact with a second portion of the semiconducting body that is separated from the first portion of the semiconducting body by a non-silicide semiconducting region.Type: ApplicationFiled: June 18, 2008Publication date: December 24, 2009Applicant: International Business Machines CorporationInventors: Leland Chang, Anthony I. Chou, Shreesh Narasimha, Jeffrey W. Sleight
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Publication number: 20090302386Abstract: A top semiconductor layer is formed with two different thicknesses such that a step is formed underneath a body region of a semiconductor-on-insulator (SOI) field effect transistor at the interface between a top semiconductor layer and an underlying buried insulator layer. The interface and the accompanying interfacial defects in the body region provide recombination centers, which increase the recombination rate between the holes and electrons in the body region. Optionally, a spacer portion, comprising a material that functions as recombination centers, is formed on sidewalls of the step to provide an enhanced recombination rate between holes and electrons in the body region, which increases the bipolar breakdown voltage of a SOI field effect transistor.Type: ApplicationFiled: June 5, 2008Publication date: December 10, 2009Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Anthony I. Chou, Andres Bryant, Arvind Kumar, Shreesh Narasimha
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Publication number: 20090294854Abstract: Superior control of short-channel effects for an ultra-thin semiconductor-on-insulator field effect transistor (UTSOI-FET) is obtained by performing a halo implantation immediately after a gate reoxidation step. An offset is then formed and thereafter an extension implantation process is performed. This sequence of processing steps ensures that the halo implant is laterally separated from the extension implant by the width of the offset spacer. This construction produces equivalent or far superior short channel performance compared to conventional UTSOI-FETs. Additionally, the above processing steps permit the use of lower halo doses as compared to conventional processes.Type: ApplicationFiled: August 8, 2009Publication date: December 3, 2009Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Omer H. Dokumaci, John M. Hergenrother, Shreesh Narasimha, Jeffrey W. Sleight
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Patent number: 7627836Abstract: An iterative timing analysis is analytically performed before a chip is fabricated, based on a methodology using optical proximity correction techniques for shortening the gate lengths and adjusting metal line widths and proximity distances of critical time sensitive devices. The additional mask is used as a selective trim to form shortened gate lengths or wider metal lines for the selected, predetermined transistors, affecting the threshold voltages and the RC time constants of the selected devices. Marker shapes identify a predetermined subgroup of circuitry that constitutes the devices in the critical timing path. The analysis methodology is repeated as often as needed to improve the timing of the circuit with shortened designed gate lengths and modified RC timing constants until manufacturing limits are reached. A mask is made for the selected critical devices using OPC techniques.Type: GrantFiled: November 8, 2005Date of Patent: December 1, 2009Assignee: International Business Machines CorporationInventors: James A. Culp, Lars W. Liebmann, Rajeev Malik, K. Paul Muller, Shreesh Narasimha, Stephen L. Runyon, Patrick M. Williams
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Patent number: 7595247Abstract: Superior control of short-channel effects for an ultra-thin semiconductor-on-insulator field effect transistor (UTSOI-FET) is obtained by performing a halo implantation immediately after a gate reoxidation step. An offset is then formed and thereafter an extension implantation process is performed. This sequence of processing steps ensures that the halo implant is laterally separated from the extension implant by the width of the offset spacer. This construction produces equivalent or far superior short channel performance compared to conventional UTSOI-FETs. Additionally, the above processing steps permit the use of lower halo doses as compared to conventional processes.Type: GrantFiled: May 25, 2007Date of Patent: September 29, 2009Assignee: International Business Machines CorporationInventors: Omer H. Dokumaci, John M. Hergenrother, Shreesh Narasimha, Jeffrey W. Sleight