Patents by Inventor Dureseti Chidambarrao

Dureseti Chidambarrao 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: 20110049473
    Abstract: A semiconductor structure includes an n-channel field effect transistor (NFET) nanowire, the NFET nanowire comprising a film wrapping around a core of the NFET nanowire, the film wrapping configured to provide tensile stress in the NFET nanowire. A method of making a semiconductor structure includes growing a film wrapping around a core of an n-channel field effect transistor (NFET) nanowire of the semiconductor structure, the film wrapping being configured to provide tensile stress in the NFET nanowire.
    Type: Application
    Filed: August 28, 2009
    Publication date: March 3, 2011
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Dureseti Chidambarrao, Lidija Sekaric
  • Patent number: 7888197
    Abstract: A method is provided for fabricating a semiconductor-on-insulator (“SOI”) substrate. In such method an SOI substrate is formed to include (i) an SOI layer of monocrystalline silicon separated from (ii) a bulk semiconductor layer by (iii) a buried oxide (“BOX”) layer including a layer of doped silicate glass. A sacrificial stressed layer is deposited onto the SOI substrate to overlie the SOI layer. Trenches are then etched through the sacrificial stressed layer and into the SOI layer. The SOI substrate is heated with the sacrificial stressed layer sufficiently to cause the glass layer to soften and the sacrificial stressed layer to relax, to thereby apply a stress to the SOI layer to form a stressed SOI layer. The trenches in the stressed SOI layer are then filled with a dielectric material to form trench isolation regions contacting peripheral edges of the stressed SOI layer, the trench isolation regions extending downwardly from a major surface of the stressed SOI layer towards the BOX layer.
    Type: Grant
    Filed: January 11, 2007
    Date of Patent: February 15, 2011
    Assignee: International Business Machines Corporation
    Inventors: Dureseti Chidambarrao, William K. Henson, Yaocheng Liu
  • Publication number: 20110012176
    Abstract: An electronic device includes a conductive channel defining a crystal structure and having a length and a thickness tC; and a dielectric film of thickness tg in contact with a surface of the channel. Further, the film comprises a material that exerts one of a compressive or a tensile force on the contacted surface of the channel such that electrical mobility of the charge carriers (electrons or holes) along the channel length is increased due to the compressive or tensile force in dependence on alignment of the channel length relative to the crystal structure. Embodiments are given for chips with both hole and electron mobility increased in different transistors, and a method for making such a transistor or chip.
    Type: Application
    Filed: July 20, 2009
    Publication date: January 20, 2011
    Inventors: Dureseti CHIDAMBARRAO, Xiao Hu LIU, Lidija SEKARIC
  • Publication number: 20110012177
    Abstract: A structure and a method for a semiconductor including a nanostructure semiconductor channel. The semiconductor may include a dielectric and an electrode, the electrode attached to the dielectric, a semiconductor channel may be disposed proximate to the dielectric, wherein the semiconductor channel has an electric mobility and is configured to have at least one dimension, and wherein the dielectric may be configured to apply a force at the at least one dimension.
    Type: Application
    Filed: July 20, 2009
    Publication date: January 20, 2011
    Inventors: Dureseti Chidambarrao, Oki Gunawan, Xiao Hu Liu, Amlan Majumdar, Lidija Sekaric, Jeffrey W. Sleight
  • Patent number: 7863197
    Abstract: A method for fabricating the semiconductor structure include a semiconductor substrate having a cross-section hourglass shaped channel region. A stress imparting layer is located adjacent the channel region. The hourglass shape may provide for enhanced vertical tensile stress within the channel region when it is longitudinally compressive stressed by the stress imparting layer.
    Type: Grant
    Filed: January 9, 2006
    Date of Patent: January 4, 2011
    Assignee: International Business Machines Corporation
    Inventors: Huajie Chen, Dureseti Chidambarrao, Judson R. Holt, Qiqing C. Ouyang, Siddhartha Panda
  • Publication number: 20100330783
    Abstract: A contiguous block of a stack of two heterogeneous semiconductor layers is formed over an insulator region such as shallow trench isolation. A portion of the contiguous block is exposed to an etch, while another portion is masked during the etch. The etch removes an upper semiconductor layer selective to a lower semiconductor layer in the exposed portion. The etch mask is removed and the entirety of the lower semiconductor layer within the exposed region is metallized. A first metal semiconductor alloy vertically abutting the insulator region is formed, while exposed surfaces of the stack of two heterogeneous semiconductor layers, which comprises the materials of the upper semiconductor layer, are concurrently metallized to form a second metal semiconductor alloy. An inflection point for current and, consequently, a region of flux divergence are formed at the boundary of the two metal semiconductor alloys.
    Type: Application
    Filed: September 1, 2010
    Publication date: December 30, 2010
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Dureseti Chidambarrao, William K. Henson, Deok-Kee Kim, Chandrasekharan Kothandaraman
  • Patent number: 7843024
    Abstract: A method and semiconductor structure that overcome the dual stress liner boundary problem, without significantly increasing the overall size of the integrated circuit, are provided. In accordance with the present invention, the dual stress liner boundary or gap therebetween is forced to land on a neighboring dummy gate region. By forcing the dual stress liner boundary or gap between the liners to land on the dummy gate region, the large stresses associated with the dual stress liner boundary or gap are transferred to the dummy gate region, not the semiconductor substrate. Thus, the impact of the dual stress liner boundary on the nearest neighboring FET is reduced. Additionally, benefits of device variability and packing density are achieved utilizing the present invention.
    Type: Grant
    Filed: December 4, 2008
    Date of Patent: November 30, 2010
    Assignee: International Business Machines Corporation
    Inventors: Dureseti Chidambarrao, Brian J. Greene
  • Patent number: 7838963
    Abstract: A contiguous block of a stack of two heterogeneous semiconductor layers is formed over an insulator region such as shallow trench isolation. A portion of the contiguous block is exposed to an etch, while another portion is masked during the etch. The etch removes an upper semiconductor layer selective to a lower semiconductor layer in the exposed portion. The etch mask is removed and the entirety of the lower semiconductor layer within the exposed region is metallized. A first metal semiconductor alloy vertically abutting the insulator region is formed, while exposed surfaces of the stack of two heterogeneous semiconductor layers, which comprises the materials of the upper semiconductor layer, are concurrently metallized to form a second metal semiconductor alloy. An inflection point for current and, consequently, a region of flux divergence are formed at the boundary of the two metal semiconductor alloys.
    Type: Grant
    Filed: October 26, 2007
    Date of Patent: November 23, 2010
    Assignee: International Business Machines Corporation
    Inventors: Dureseti Chidambarrao, William K. Henson, Deok-Kee Kim, Chandrasekharan Kothandaraman
  • Patent number: 7838932
    Abstract: An embedded silicon carbon (Si:C) having a substitutional carbon content in excess of one percent in order to effectively increase electron mobility by application of tension to a channel region of an NFET is achieved by overfilling a gap or trench formed by transistor gate structures with Si:C and polishing an etching the Si:C to or below a surface of a raised gate structure in a super-Damascene process, leaving Si:C only in selected regions above the transistor source and drain, even though processes capable of depositing Si:C with sufficiently high substitutional carbon content are inherently non-selective.
    Type: Grant
    Filed: February 8, 2008
    Date of Patent: November 23, 2010
    Assignee: International Business Machines Corporation
    Inventors: Ashima B. Chakravarti, Dureseti Chidambarrao, Judson R. Holt, Yaocheng Liu, Kern Rim
  • Publication number: 20100289085
    Abstract: A semiconductor structure is provided that includes an asymmetric gate stack located on a surface of high k gate dielectric. The asymmetric gate stack includes a first portion and a second portion, wherein the first portion has a different threshold voltage than the second portion. The first portion of the inventive asymmetric gate stack includes, from bottom to top, a threshold voltage adjusting material and at least a first conductive spacer, while the second portion of the inventive asymmetric gate stack includes at least a second conductive spacer over the gate dielectric. In some embodiments, the second conductive spacer is in direct contact with the underlying high k gate dielectric, while in other embodiments, in which the first and second conductive spacers are comprised of different conductive materials, the base of the second conductive spacer is in direct contact with the threshold adjusting material.
    Type: Application
    Filed: May 14, 2009
    Publication date: November 18, 2010
    Applicant: International Business Machines Corporation
    Inventors: Jun Yuan, Dureseti Chidambarrao, Sunfei Fang, Haizhou Yin, Yue Liang, Xiaojun Yu
  • Patent number: 7831941
    Abstract: A methodology for obtaining improved prediction of CA resistance in electronic circuits and, particularly, an improved CA resistance model adapted to capture larger than anticipated “out of spec” regime. In one embodiment, a novel bucketization scheme is implemented that is codified to provide a circuit designer with considerably better design options for handling large CA variability as seen through the design manual. The tools developed for modeling the impact of CA variable resistance phenomena provide developers with a resistance model, such as conventionally known, modified with a new CA model Basis including a novel CA intrinsic resistance model, and, a novel CA layout bucketization model.
    Type: Grant
    Filed: January 2, 2008
    Date of Patent: November 9, 2010
    Assignee: International Business Machines Corporation
    Inventors: Dureseti Chidambarrao, Fook-Luen Heng, Mark A. Lavin, Jin-Fuw Lee, Rama N. Singh, Roger Y. Tsai
  • Publication number: 20100269079
    Abstract: A method for implementing systematic, variation-aware integrated circuit extraction includes inputting a set of processing conditions to a plurality of variation models, each model corresponding to a separate systematic, parametric variation associated with semiconductor manufacturing of an integrated circuit layout; generating, for each variation model, a netlist update attributable to the associated variation, wherein the netlist update is an update with respect to an original netlist extracted from the integrated circuit layout; and storing the netlist updates generated for each of the processing conditions.
    Type: Application
    Filed: April 20, 2009
    Publication date: October 21, 2010
    Applicant: International Business Machines Corporation
    Inventors: Shayak Banerjee, Dureseti Chidambarrao, James A. Culp, Praveen Elakkumanan, Saibal Mukhopadhyay
  • Patent number: 7818692
    Abstract: A method of improving a circuit design for a very large scale integrated circuit is provided which represents a plurality of semiconductor devices interconnected in a circuit. It is determined whether an edge of a feature of one of the plurality of semiconductor devices in the design can be moved in a first direction by a distance within a permitted range, such that a performance goal and a matching goal for the circuit are served. If so, the edge is moved in the first direction by the distance calculated to best serve the performance goal and the matching goal. The foregoing steps may be repeated for each of the plurality of semiconductor devices. If necessary, the foregoing steps may be repeated until the performance goal and matching goal for the circuit are deemed to be adequately served.
    Type: Grant
    Filed: November 29, 2007
    Date of Patent: October 19, 2010
    Assignee: International Business Machines Corporation
    Inventors: Dureseti Chidambarrao, Jason Hibbeler, Richard Q. Williams
  • Patent number: 7818693
    Abstract: 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: Grant
    Filed: January 8, 2008
    Date of Patent: October 19, 2010
    Assignee: International Business Machines Corporation
    Inventors: Dureseti Chidambarrao, Gerald M. Davidson, Paul A. Hyde, Judith H. McCullen, Shreesh Narasimha
  • Patent number: 7812397
    Abstract: A MOSFET structure includes a planar semiconductor substrate, a gate dielectric and a gate. A UT SOI channel extends to a first depth below the top surface of the substrate and is self-aligned to and is laterally coextensive with the gate. Source-drain regions, extend to a second depth greater than the first depth below the top surface, and are self-aligned to the UT channel region. A BOX1 region extends across the entire structure, and vertically from the second depth to a third depth below the top surface. An upper portion of a BOX2 region under the UT channel region is self-aligned to and is laterally coextensive with the gate, and extends vertically from the first depth to a third depth below the top surface, and where the third depth is greater than the second depth.
    Type: Grant
    Filed: July 1, 2008
    Date of Patent: October 12, 2010
    Assignee: International Business Machines Corporation
    Inventors: Changguo Cheng, Dureseti Chidambarrao, Brian Joseph Greene, Jack A. Mandelman, Kern Rim
  • Publication number: 20100252814
    Abstract: Prototype semiconductor structures each including a semiconductor link portion and two adjoined pad portions are formed by lithographic patterning of a semiconductor layer on a dielectric material layer. The sidewalls of the semiconductor link portions are oriented to maximize hole mobility for a first-type semiconductor structures, and to maximize electron mobility for a second-type semiconductor structures. Thinning by oxidation of the semiconductor structures reduces the width of the semiconductor link portions at different rates for different crystallographic orientations. The widths of the semiconductor link portions are predetermined so that the different amount of thinning on the sidewalls of the semiconductor link portions result in target sublithographic dimensions for the resulting semiconductor nanowires after thinning.
    Type: Application
    Filed: April 3, 2009
    Publication date: October 7, 2010
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Lidija Sekaric, Tymon Barwicz, Dureseti Chidambarrao
  • Publication number: 20100252815
    Abstract: In one embodiment, a semiconductor nanowire having a monotonically increasing width with distance from a middle portion toward adjoining semiconductor pads is provided. A semiconductor link portion having tapered end portions is lithographically patterned. During the thinning process that forms a semiconductor nanowire, the taper at the end portions of the semiconductor nanowire provides enhanced mechanical strength to prevent structural buckling or bending. In another embodiment, a semiconductor nanowire having bulge portions are formed by preventing the thinning of a semiconductor link portion at pre-selected positions. The bulge portions having a greater width than a middle portion of the semiconductor nanowire provides enhanced mechanical strength during thinning of the semiconductor link portion so that structural damage to the semiconductor nanowire is avoided during thinning.
    Type: Application
    Filed: April 3, 2009
    Publication date: October 7, 2010
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Dureseti Chidambarrao, Lidija Sekaric
  • Publication number: 20100252801
    Abstract: A semiconductor nanowire having two semiconductor pads on both ends is suspended over a substrate. Stress-generating liner portions are formed over the two semiconductor pads, while a middle portion of the semiconductor nanowire is exposed. A gate dielectric and a gate electrode are formed over the middle portion of the semiconductor nanowire while the semiconductor nanowire is under longitudinal stress due to the stress-generating liner portions. The middle portion of the semiconductor nanowire is under a built-in inherent longitudinal stress after removal of the stress-generating liners because the formation of the gate dielectric and the gate electrode locks in the strained state of the semiconductor nanowire. Source and drain regions are formed in the semiconductor pads to provide a semiconductor nanowire transistor. A middle-of-line (MOL) dielectric layer may be formed directly on the source and drain pads.
    Type: Application
    Filed: April 3, 2009
    Publication date: October 7, 2010
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Lidija Sekaric, Dureseti Chidambarrao, Xiao H. Liu
  • Publication number: 20100252800
    Abstract: A p-type semiconductor nanowire transistor is formed on the first semiconductor nanowire and an n-type semiconductor nanowire transistor is formed on the second semiconductor nanowire. The first and second semiconductor nanowires have a rectangular cross-sectional area with different width-to-height ratios. The type of semiconductor nanowires for each semiconductor nanowire transistor is selected such that top and bottom surfaces provide a greater on-current per unit width than sidewall surfaces in a semiconductor nanowire having a greater width-to-height ratio, while sidewall surfaces provide a greater on-current per unit width than top and bottom surfaces in the other semiconductor nanowire having a lesser width-to-height ratio. Different types of stress-generating material layers may be formed on the first and second semiconductor nanowire transistors to provide opposite types of stress, which may be employed to enhance the on-current of the first and second semiconductor nanowire transistors.
    Type: Application
    Filed: April 3, 2009
    Publication date: October 7, 2010
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Dureseti Chidambarrao, Xiao H. Liu, Lidija Sekaric
  • Patent number: 7791144
    Abstract: The invention relates to a semiconductor structure and method of manufacturing and more particularly to a CMOS device with a stress inducing material embedded in both gates and also in the source/drain of the PFET and varying thickness of the PFET and NFET channel. In one embodiment, the structure enhances the device performance by varying the thickness of the top Silicon layer respective to the NFET or the PFET.
    Type: Grant
    Filed: July 21, 2009
    Date of Patent: September 7, 2010
    Assignee: International Business Machines Corporation
    Inventors: Dureseti Chidambarrao, Ricardo A. Donaton, William K. Henson, Kern Rim