Patents by Inventor Sundar Kumar Iyer

Sundar Kumar Iyer 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).

  • Patent number: 6998865
    Abstract: A test arrangement includes a semiconductor device, a first conductive pad electrically connected to the semiconductor device, a second conductive pad, and a programmable fuse. The second conductive pad is electrically connected to the semiconductor device through the programmable fuse.
    Type: Grant
    Filed: December 10, 2001
    Date of Patent: February 14, 2006
    Assignee: International Business Machines Corporation
    Inventors: Karen A. Bard, S. Sundar Kumar Iyer
  • Patent number: 6781436
    Abstract: A transistor (such as a MOSFET) is operated in its breakdown region, as opposed to its saturation region, to program an electric fuse. With the programming transistor operated in the breakdown region, a much higher current is enabled than the associated saturation current for the same size transistor. Thus, a smaller transistor can be used for programming the fuse. Cooperative with transistor operation in the breakdown region, a dynamic current compliance device is used to limit the peak current to prevent damage than can result from excessive current flowing through the transistor. The current compliance device can be external to the integrated fuse and programming transistor circuit.
    Type: Grant
    Filed: July 25, 2002
    Date of Patent: August 24, 2004
    Assignee: Infineon Technologies AG
    Inventors: Chandrasekharan Kothandaraman, S. Sundar Kumar Iyer
  • Publication number: 20040056703
    Abstract: A transistor (such as a MOSFET) is operated with the well biased, as opposed to being grounded, to program an electric fuse. With the programming transistor operated with an active well bias, more energy is enabled for programming the fuse than is available with a grounded well for the same size transistor. Thus, a smaller transistor can be used of programming the fuse. In a multiple fuse embodiment, the programming transistors can be arranged in the same “well” with a common independent Vbias applied, via a body control circuit, to the entire well during programming of a select fuse.
    Type: Application
    Filed: September 19, 2002
    Publication date: March 25, 2004
    Inventors: Chandrasekharan Kothandaraman, S. Sundar Kumar Iyer
  • Patent number: 6710640
    Abstract: A transistor (such as a MOSFET) is operated with the well biased, as opposed to being grounded, to program an electric fuse. With the programming transistor operated with an active well bias, more energy is enabled for programming the fuse than is available with a grounded well for the same size transistor. Thus, a smaller transistor can be used of programming the fuse. In a multiple fuse embodiment, the programming transistors can be arranged in the same “well” with a common independent Vbias applied, via a body control circuit, to the entire well during programming of a select fuse.
    Type: Grant
    Filed: September 19, 2002
    Date of Patent: March 23, 2004
    Assignees: Infineon Technologies AG, International Business Machines Corporation
    Inventors: Chandrasekharan Kothandaraman, S. Sundar Kumar Iyer
  • Publication number: 20040017246
    Abstract: A transistor (such as a MOSFET) is operated in its breakdown region, as opposed to its saturation region, to program an electric fuse. With the programming transistor operated in the breakdown region, a much higher current is enabled than the associated saturation current for the same size transistor. Thus, a smaller transistor can be used for programming the fuse. Cooperative with transistor operation in the breakdown region, a dynamic current compliance device is used to limit the peak current to prevent damage than can result from excessive current flowing through the transistor. The current compliance device can be external to the integrated fuse and programming transistor circuit.
    Type: Application
    Filed: July 25, 2002
    Publication date: January 29, 2004
    Inventors: Chandrasekharan Kothandaraman, S. Sundar Kumar Iyer
  • Patent number: 6624499
    Abstract: The present invention provides a system, apparatus and method of programming via electromigration. A semiconductor fuse which includes a cathode and an anode coupled by a fuse link having an electrically conductive component, such as silicide, is coupled to a power supply. A potential is applied across the conductive fuse link via the cathode and anode in which the potential is of a magnitude to initiate electromigration of silicide from a region of the semiconductor fuse reducing the conductivity of the fuse link. The electromigration is enhanced by effectuating a temperature gradient between the fuse link and one of the cathode and anode responsive to the applied potential. Portions of the semiconductor fuse are selectively cooled in a heat transfer relationship to increase the temperature gradient. In one embodiment, a heat sink is applied to the cathode. The heat sink can be a layer of metal coupled in close proximity to the cathode while insulated from the fuse link.
    Type: Grant
    Filed: September 19, 2002
    Date of Patent: September 23, 2003
    Assignees: Infineon Technologies AG, International Business Machines Corporation
    Inventors: Chandrasekharan Kothandaraman, S. Sundar Kumar Iyer, Subramanian Iyer, Chandrasekhar Narayan
  • Publication number: 20030160297
    Abstract: The present invention provides a system, apparatus and method of programming via electromigration. A semiconductor fuse which includes a cathode and an anode coupled by a fuse link having an electrically conductive component, such as silicide, is coupled to a power supply. A potential is applied across the conductive fuse link via the cathode and anode in which the potential is of a magnitude to initiate electromigration of silicide from a region of the semiconductor fuse reducing the conductivity of the fuse link. The electromigration is enhanced by effectuating a temperature gradient between the fuse link and one of the cathode and anode responsive to the applied potential. Portions of the semiconductor fuse are selectively cooled in a heat transfer relationship to increase the temperature gradient. In one embodiment, a heat sink is applied to the cathode. The heat sink can be a layer of metal coupled in close proximity to the cathode while insulated from the fuse link.
    Type: Application
    Filed: September 19, 2002
    Publication date: August 28, 2003
    Inventors: Chandrasekharan Kothandaraman, S. Sundar Kumar Iyer, Subramanian Iyer, Chandrasekhar Narayan
  • Publication number: 20030107391
    Abstract: A test arrangement includes a semiconductor device, a first conductive pad electrically connected to the semiconductor device, a second conductive pad, and a programmable fuse. The second conductive pad is electrically connected to the semiconductor device through the programmable fuse.
    Type: Application
    Filed: December 10, 2001
    Publication date: June 12, 2003
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Karen A. Bard, S. Sundar Kumar Iyer
  • Publication number: 20020197836
    Abstract: A method for forming variable oxide thicknesses across semiconductor chips comprises providing a silicon semiconductor substrate having pre-selected areas open to silicon surface using a photoresist layer; immersing the silicon semiconductor substrate in an HF type electrolytic bath to produce a porous silicon area; and removing the photoresist layer and oxidizing the silicon semiconductor substrate to produce a plurality of thicknesses of gate oxide on the silicon semiconductor substrate.
    Type: Application
    Filed: June 11, 2001
    Publication date: December 26, 2002
    Applicant: International Business Machines Corporation
    Inventors: S. Sundar Kumar Iyer, Suryanarayan G. Hegde, Erin Catherine Jones, Harald F. Okorn-Schmidt
  • Patent number: 6486043
    Abstract: A method for forming a semiconductor devices structure includes providing a semiconductor substrate, forming a deep trench continuously in the substrate to separate a first region from a second region, and then forming a silicon-on-insulator region in the first region while maintaining a non-silicon-on-insulator region in the second region. The deep trench has a depth which is at least as deep as the depth of the buried oxide in the substrate. The invention also includes a device structure resulting from the method.
    Type: Grant
    Filed: August 31, 2000
    Date of Patent: November 26, 2002
    Assignee: International Business Machines Corporation
    Inventors: Robert Hannon, Herbert L. Ho, Subramanian Iyer, S. Sundar Kumar Iyer
  • Patent number: 6368902
    Abstract: Described herein is a fuse incorporating a covering layer disposed on a conductive layer, which is disposed on a polysilicon layer. The covering layer preferably comprises a relatively inert material, such as a nitride etchant barrier. The covering layer preferably has a region of relatively less-inert filler material. Upon programming of the fuse, the conductive layer, which can be a silicide, preferentially degrades in the region underlying the filler material of the covering layer. This preferential degradation results in a predictable “blowing” of the fuse in the fuse region underlying the filler material. Since the “blow” area is predictable, damage to adjacent structures can be minimized or eliminated.
    Type: Grant
    Filed: May 30, 2000
    Date of Patent: April 9, 2002
    Assignee: International Business Machines Corporation
    Inventors: Chandrasekharan Kothandaraman, Frank Grellner, Sundar Kumar Iyer
  • Patent number: 6096580
    Abstract: A low programming voltage anti-fuse formed by a MOSFET (or MOS) or by a deep trench (DT) capacitor structure is described. Lowering the programming voltage is achieved by implanting a dose of heavy ions, such as indium, into the dielectric directly on the substrate or indirectly through a layer of polysilicon. The programming voltage can also be lowered on the MOSFET/MOS capacitor anti-fuse by accentuating the corners of active areas and gate areas of the device with suitable layout masks during processing. Silicon active area corner rounding steps should also be avoided in the fabrication of the anti-fuse to reduce the programming voltage. In the DT capacitor, lowering the programming voltage may be achieved by implanting the node dielectric of the DT anti-fuse with heavy ions either directly or through a conformal layer of polysilicon deposited on it or after the first amorphous silicon recess step during the fabrication of the DT capacitor.
    Type: Grant
    Filed: September 24, 1999
    Date of Patent: August 1, 2000
    Assignee: International Business Machines Corporation
    Inventors: S. Sundar Kumar Iyer, Liang-Kai Han, Robert Hannon, Subramanian S. Iyer, Mukesh V. Khare