Patents by Inventor Chandrasekharan Kothandaraman

Chandrasekharan Kothandaraman 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: 20090096059
    Abstract: A fuse structure, a method for fabricating the fuse structure and a method for programming a fuse within the fuse structure each use a fuse material layer that is used as a fuse, and located upon a monocrystalline semiconductor material layer in turn located over a substrate. At least part of the monocrystalline semiconductor material layer is separated from the substrate by a gap. Use of the monocrystalline semiconductor material layer, as well as the gap, provides for enhanced uniformity and reproducibility when programming the fuse.
    Type: Application
    Filed: October 10, 2007
    Publication date: April 16, 2009
    Applicant: International Business Machines Corporation
    Inventors: Anil Kumar Chinthakindi, Deok-kee Kim, Chandrasekharan Kothandaraman, Byeongju Park
  • Publication number: 20090090993
    Abstract: An integrated eFUSE device is formed by forming a silicon “floating beam” on air, whereupon the fusible portion of the eFUSE device resides. This beam extends between two larger, supporting terminal structures. “Undercutting” techniques are employed whereby a structure is formed atop a buried layer, and that buried layer is removed by selective etching. Whereby a “floating” silicide eFUSE conductor is formed on a silicon beam structure. In its initial state, the eFUSE silicide is highly conductive, exhibiting low electrical resistance (the “unblown state of the eFUSE). When a sufficiently large current is passed through the eFUSE conductor, localized heating occurs. This heating causes electromigration of the silicide into the silicon beam (and into surrounding silicon, thereby diffusing the silicide and greatly increasing its electrical resistance. When the current source is removed, the silicide remains permanently in this diffused state, the “blown” state of the eFUSE.
    Type: Application
    Filed: October 4, 2007
    Publication date: April 9, 2009
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: William K. Henson, Deok-Kee Kim, Chandrasekharan Kothandaraman, Byeongju Park
  • Patent number: 7504875
    Abstract: An integrated circuit device having at least one fuse capable of being blown in order to provide measurements of fuse current-voltage characteristics is provided. The integrated circuit device also provides at least one pulse generation circuit associated with the fuse and capable of generating a pulse to blow the fuse through one or more DC input signals.
    Type: Grant
    Filed: October 25, 2007
    Date of Patent: March 17, 2009
    Assignee: International Business Machines Corporation
    Inventors: Manjul Bhushan, Mark B. Ketchen, Chandrasekharan Kothandaraman, Edward P. Maciejewski
  • Publication number: 20090065761
    Abstract: A programmable phase change material (PCM) structure includes a heater element formed at a BEOL level of a semiconductor device, the BEOL level including a low-K dielectric material therein; a first via in electrical contact with a first end of the heater element and a second via in electrical contact with a second end of the heater element, thereby defining a programming current path which passes through the first via, the heater element, and the second via; a PCM element disposed above the heater element, the PCM element configured to be programmed between a lower resistance crystalline state and a higher resistance amorphous state through the use of programming currents through the heater element; and a third via in electrical contact with the PCM element, thereby defining a sense current path which passes through the third via, the PCM element, the heater element, and the second via.
    Type: Application
    Filed: September 6, 2007
    Publication date: March 12, 2009
    Applicant: INTERNATIONAL BUSINESS MACHINE CORPORATION
    Inventors: Kuang-Neng Chen, Bruce G. Elmegreen, Deok-Kee Kim, Chandrasekharan Kothandaraman, Chung Hon Lam, Lia Krusin-Elbaum, Dennis M. Newns, Byeongju Park, Sampath Purushothaman
  • Publication number: 20090051003
    Abstract: A method for fabricating an eFuse, the method comprising disposing a crystalline silicon eFuse on a substrate having a fuse link portion, a first contact portion, and a second contact portion, wherein the fuse link is oriented parallel to the silicon crystal {110} plane direction, etching the eFuse using crystallographic orientation dependent wet etching in the {110} plane direction such that a corner at a junction of the fuse link an a contact portion is substantially square, operative to increase current density when an electric current flows through the fuse link, and forming a silicide layer atop the eFuse.
    Type: Application
    Filed: August 23, 2007
    Publication date: February 26, 2009
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Kangguo Cheng, Deok-kee Kim, Chandrasekharan Kothandaraman
  • Publication number: 20090045388
    Abstract: A structure including a phase change material and a related method are disclosed. The structure may include a first electrode; a second electrode; a third electrode; a phase change material electrically connecting the first, second and third electrodes for passing a first current through two of the first, second and third electrodes; and a refractory metal barrier heater layer about the phase change material for converting the phase change material between an amorphous, insulative state and a crystalline, conductive state by application of a second current to the phase change material. The structure may be used as a fuse or a phase change material random access memory (PRAM).
    Type: Application
    Filed: August 16, 2007
    Publication date: February 19, 2009
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Lawrence A. Clevenger, Bruce G. Elmegreen, Deok-Kee Kim, Chandrasekharan Kothandaraman, Lia Krusin-Elbaum, Chung H. Lam, Dennis M. Newns
  • Publication number: 20090040006
    Abstract: A layer of semiconductor material is patterned to form a cathode semiconductor portion, a fuselink semiconductor portion, and an anode semiconductor portion. A first metal layer is deposited on the patterned semiconductor material layer. A dielectric material layer is deposited and lithographically patterned to cover a middle portion of the fuselink, followed by a deposition of a second metal layer. A thin metal semiconductor alloy is formed in the middle of the fuselink and thick metal semiconductor alloy alloys are formed abutting the thin metal semiconductor alloy alloy. The resulting inventive electrical fuse has interfaces at which a thinner metal semiconductor alloy abuts a thicker metal semiconductor alloy in the fuselink. The divergence of electrical current is enhanced at the interfaces due to a sudden change of a cross-sectional area available for current conduction.
    Type: Application
    Filed: August 8, 2007
    Publication date: February 12, 2009
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Dureseti Chidambarrao, William K. Henson, Deok-kee Kim, Chandrasekharan Kothandaraman
  • Publication number: 20090039331
    Abstract: Structures including a phase change material are disclosed. The structure may include a first electrode; a second electrode; a phase change material electrically connecting the first electrode and the second electrode for passing a current therethrough; and a tantalum nitride heater layer about the phase change material for converting the phase change material between an amorphous, insulative state and a crystalline, conductive state by application of a second current to the phase change material. The structure may be used as a fuse or a phase change material random access memory (PRAM).
    Type: Application
    Filed: August 7, 2007
    Publication date: February 12, 2009
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Lawrence A. Clevenger, Bruce G. Elmegreen, Deok-Kee Kim, Chandrasekharan Kothandaraman, Lia Krusin-Elbaum, Chung H. Lam, Dennis M. Newns
  • Publication number: 20090042341
    Abstract: A metal layer is deposited on the patterned semiconductor material layer containing a cathode semiconductor portion, a fuselink semiconductor portion, and an anode semiconductor portion. The metal layer may be patterned so that a middle portion of the fuselink semiconductor portion has a thin metal layer, which upon annealing produces a thinner metal semiconductor alloy portion than surrounding metal semiconductor alloy portion on the fuselink semiconductor portion. Alternatively, a middle portion of the metal semiconductor alloy having a uniform thickness throughout the fuselink may be lithographically patterned and etched to form a thin metal semiconductor alloy portion in the middle of the fuselink, while thick metal semiconductor alloy portions are formed on the end portions of the fuselink. The resulting inventive electrical fuse has interfaces at which a thinner metal semiconductor alloy abuts a thicker metal semiconductor alloy in the fuselink to enhance the divergence of electrical current.
    Type: Application
    Filed: August 8, 2007
    Publication date: February 12, 2009
    Applicant: International Business Machines Corporation
    Inventors: Dureseti Chidambarrao, William K. Henson, Deok-kee Kim, Chandrasekharan Kothandaraman
  • Patent number: 7485944
    Abstract: A programmable device (eFuse), includes: a substrate (10); an insulator (13) on the substrate; an elongated semiconductor material (12) on the insulator, the elongated semiconductor material having a first end (12a), a second end (12b), a fuse link (11) between the ends, and an upper surface S. The semiconductor material includes a dopant having a concentration of at least 10*17/cc. The first end (12a) is wider than the second end (12b), and a metallic material is disposed on the upper surface. The metallic material is physically migratable along the upper surface responsive to an electrical current I flowable through the semiconductor material and through the metallic material.
    Type: Grant
    Filed: October 21, 2004
    Date of Patent: February 3, 2009
    Assignee: International Business Machines Corporation
    Inventors: Chandrasekharan Kothandaraman, Subramanian Iyer
  • Patent number: 7442583
    Abstract: Techniques and systems whereby operation of and/or access to particular features of an electronic device may be controlled after the device has left the control of the manufacturer are provided. The operation and/or access may be provided based on values stored in non-volatile storage elements, such as electrically programmable fused (eFUSES).
    Type: Grant
    Filed: December 17, 2004
    Date of Patent: October 28, 2008
    Assignee: International Business Machines Corporation
    Inventors: Anthony R. Bonaccio, Karl R. Erickson, John A. Fifield, Chandrasekharan Kothandaraman, Phil C. Paone, William R. Tonti
  • Patent number: 7436044
    Abstract: The present invention relates to electrical fuses that each comprises at least one thin film transistor. In one embodiment, the electrical fuse of the present invention comprises a hydrogenated thin film transistor with an adjacent heating element. Programming of such an electrical fuse can be effectuated by heating the hydrogenated thin film transistor so as to cause at least partial dehydrogenation. Consequentially, the thin film transistor exhibits detectible physical property change(s), which defines a programmed state. In an alternative embodiment of the present invention, the electrical fuse comprises a thin film transistor that is either hydrogenated or not hydrogenated. Programming of such an alternative electrical fuse can be effectuated by applying a sufficient high back gate voltage to the thin film transistor to cause state changes in the channel-gate interface. In this manner, the thin film transistor also exhibits detectible property change(s) to define a programmed state.
    Type: Grant
    Filed: January 4, 2006
    Date of Patent: October 14, 2008
    Assignee: International Business Machines Corporation
    Inventors: Babar A. Khan, Chandrasekharan Kothandaraman, Kai Xiu
  • Publication number: 20080232150
    Abstract: A method and structure implementing a reprogrammable read only memory (ROM) include a pair of fuse elements having different lengths and selectively arranged to define an initial bit state. A group of a plurality of the pairs of fuse elements defines a predetermined data pattern of ones and zeros, providing initial states stored in the reprogrammable ROM. The reprogrammable ROM is reprogrammed when needed by selectively blowing a selected fuse or selected fuses to change the data pattern stored in the ROM.
    Type: Application
    Filed: March 22, 2007
    Publication date: September 25, 2008
    Inventors: Roger Allen Booth, Chandrasekharan Kothandaraman, Alan James Leslie
  • Publication number: 20080232152
    Abstract: A method and structure for implementing a reprogrammable read only memory (ROM), and a design structure on which the subject circuit resides are provided. A pair of fuse elements having different lengths are selectively arranged to define an initial bit state. A group of a plurality of the pairs of fuse elements defines a predetermined data pattern of ones and zeros, providing initial states stored in the reprogrammable ROM. The reprogrammable ROM is reprogrammed when needed by selectively blowing a selected fuse or selected fuses to change the data pattern stored in the ROM.
    Type: Application
    Filed: October 16, 2007
    Publication date: September 25, 2008
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Roger Allen Booth, Chandrasekharan Kothandaraman, Alan James Leslie
  • Publication number: 20080217658
    Abstract: The present invention provides structures for antifuses that utilize electromigration for programming. By providing a portion of antifuse link with high resistance without conducting material and then by inducing electromigration of the conducting material into the antifuse link, the resistance of the antifuse structure is changed. By providing a terminal on the antifuse link, the change in the electrical properties of the antifuse link is detected and sensed. Also disclosed are an integrated antifuse with a built-in sensing device and a two dimensional array of integrated antifuses that can share programming transistors and sensing circuitry.
    Type: Application
    Filed: March 7, 2007
    Publication date: September 11, 2008
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Deok-kee Kim, Hoki Kim, Chandrasekharan Kothandaraman, Byeongju Park, John M. Safran
  • Publication number: 20080169529
    Abstract: An eFuse, includes: a substrate and an insulating layer disposed on the substrate; a first layer including a single crystal or polycrystalline silicon disposed on the insulating layer; a second layer including a single crystal or polycrystalline silicon germanium disposed on the first layer, and a third layer including a silicide disposed on the second layer. The Ge has a final concentration in a range of approximately five percent to approximately twenty-five percent.
    Type: Application
    Filed: January 12, 2007
    Publication date: July 17, 2008
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Deok-Kee Kim, Dureseti Chidambarrao, William K. Henson, Chandrasekharan Kothandaraman
  • Publication number: 20080170457
    Abstract: A method for sensing an electrical signal includes the steps of: providing an arrangement having a fuse connected in series to an antifuse, the arrangement further having an output tap connected to an intermediate node located between the fuse and the antifuse; programming the fuse and the antifuse; applying a sense signal across the combination of the programmed fuse and the programmed antifuse, and then measuring an output signal at the output tap.
    Type: Application
    Filed: January 12, 2007
    Publication date: July 17, 2008
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventor: Chandrasekharan Kothandaraman
  • Patent number: 7391097
    Abstract: The present invention provides electrically-programmable fuse structures having radiation inhibitive properties for preventing non-destructive security breaches by radiation imaging techniques such as X-ray imaging, without adversely effecting fuse programmability, and methods of designing the same.
    Type: Grant
    Filed: June 10, 2005
    Date of Patent: June 24, 2008
    Assignee: International Business Machines Corporation
    Inventors: Chandrasekharan Kothandaraman, Subramanian S. Iyer
  • Publication number: 20080143373
    Abstract: Techniques and systems whereby operation of and/or access to particular features of an electronic device may be controlled after the device has left the control of the manufacturer are provided. The operation and/or access may be provided based on values stored in non-volatile storage elements, such as electrically programmable fused (eFUSES).
    Type: Application
    Filed: February 29, 2008
    Publication date: June 19, 2008
    Inventors: Anthony R. BONACCIO, Karl R. ERICKSON, John A. FIFIELD, Chandrasekharan KOTHANDARAMAN, Phil C. PAONE, William R. TONTI
  • Patent number: 7388273
    Abstract: A reversible fuse structure in an integrated circuit is obtained through the implementation of a fuse cell having a short thin line of phase change materials in contact with via and line structures capable of passing current through the line of phase change material (fuse cell). The current is passed through the fuse cell in order to change the material from a less resistive material to a more resistive material through heating the phase change material in the crystalline state to the melting point then quickly quenching the material into the amorphous state. The reversible programming is achieved by passing a lower current through the fuse cell to convert the high resistivity amorphous material to a lower resistivity crystalline material. Appropriate sense-circuitry is integrated to read the information stored in the fuses, wherein said sense circuitry is used to enable or disable circuitry.
    Type: Grant
    Filed: June 14, 2005
    Date of Patent: June 17, 2008
    Assignee: International Business Machines Corporation
    Inventors: Geoffrey W. Burr, Chandrasekharan Kothandaraman, Chung Hon Lam, Xiao Hu Liu, Stephen M. Rossnagel, Christy S. Tyberg, Robert L. Wisnieff