Patents by Inventor Subramanian S. Iyer

Subramanian S. 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: 9029988
    Abstract: A semiconductor device includes an epitaxy layer formed on semiconductor substrate, a device layer formed on the epitaxy layer, a trench formed within the semiconductor substrate and including a dielectric layer forming a liner within the trench and a conductive core forming a through-silicon via conductor, and a deep trench isolation structure formed within the substrate and surrounding the through-silicon via conductor. A region of the epitaxy layer formed between the through-silicon via conductor and the deep trench isolation structure is electrically isolated from any signals applied to the semiconductor device, thereby decreasing parasitic capacitance.
    Type: Grant
    Filed: January 17, 2013
    Date of Patent: May 12, 2015
    Assignee: International Business Machines Corporation
    Inventors: Kangguo Cheng, Subramanian S. Iyer, Pranita Kerber, Ali Khakifirooz
  • Patent number: 9025386
    Abstract: An embedded Multi-Time-Read-Only-Memory having a (MOSFET) cells' array having an initial threshold voltage (VT0) including the MOSFETs arranged in a row and column matrix, having gates in each row coupled to a wordline (WL) running in a first direction and sources in each one of the columns coupled to a bitline (BL) running in a second direction; creating two dimensional meshed source line network running in the first and second directions, in a standby state, wherein BLs and MSLN are at a voltage (VDD), and the WLs are at ground; storing a data bit by trapping charges in a dielectric of a target MOSFET, VT0 of target MOSFET increasing to another voltage (VT1) by a predetermined amount (?VT); reading a data bit by using the MOSFET threshold voltage having one of VT0 or VT1 to determine a trapped or de-trapped charge state, and resetting the data bit to a de-trapped state by de-trapping the charge.
    Type: Grant
    Filed: November 20, 2013
    Date of Patent: May 5, 2015
    Assignee: International Business Machines Corporation
    Inventors: Subramanian S. Iyer, Toshiaki Kirihata, Chandrasekharan Kothandaraman, Derek H. Leu, Dan Moy
  • Patent number: 9021411
    Abstract: A first signal is transmitted through a first path. A computing device determines a signal propagation time of the first signal. The computing device transmits a second signal through a second path, wherein the second path includes the second signal traversing across at least one interconnecting structure. The computing device determines a signal propagation time of the second signal. The computing device determines a propagation time difference between the signal propagation time of the first signal and the signal propagation time of the second signal. The computing device adjusts a clock based on the determined propagation time difference.
    Type: Grant
    Filed: May 23, 2013
    Date of Patent: April 28, 2015
    Assignee: International Business Machines Corporation
    Inventors: Anand Haridass, Subramanian S. Iyer, Saravanan Sethuraman, Ming Yin
  • Patent number: 8962448
    Abstract: A computer readable medium is provided that is encoded with a program comprising instructions for performing a method for fabricating a 3D integrated circuit structure. Provided are an interface wafer including a first wiring layer and through-silicon vias, and a first active circuitry layer wafer including active circuitry. The first active circuitry layer wafer is bonded to the interface wafer. Then, a first portion of the first active circuitry layer wafer is removed such that a second portion remains attached to the interface wafer. A stack structure including the interface wafer and the second portion of the first active circuitry layer wafer is bonded to a base wafer. Next, the interface wafer is thinned so as to form an interface layer, and metallizations coupled through the through-silicon vias in the interface layer to the first wiring layer are formed on the interface layer.
    Type: Grant
    Filed: August 10, 2012
    Date of Patent: February 24, 2015
    Assignee: International Business Machines Corporation
    Inventors: Mukta G. Farooq, Robert Hannon, Subramanian S. Iyer, Steven J. Koester, Fei Liu, Sampath Purushothaman, Albert M. Young, Roy R. Yu
  • Publication number: 20150024548
    Abstract: A computer readable medium is provided that is encoded with a program comprising instructions for performing a method for fabricating a 3D integrated circuit structure. Provided are an interface wafer including a first wiring layer and through-silicon vias, and a first active circuitry layer wafer including active circuitry. The first active circuitry layer wafer is bonded to the interface wafer. Then, a first portion of the first active circuitry layer wafer is removed such that a second portion remains attached to the interface wafer. A stack structure including the interface wafer and the second portion of the first active circuitry layer wafer is bonded to a base wafer. Next, the interface wafer is thinned so as to form an interface layer, and metallizations coupled through the through-silicon vias in the interface layer to the first wiring layer are formed on the interface layer.
    Type: Application
    Filed: August 10, 2012
    Publication date: January 22, 2015
    Applicant: International Business Machines Corporation
    Inventors: Mukta G. Farooq, Robert Hannon, Subramanian S. Iyer, Steven J. Koester, Fei Liu, Sampath Purushothaman, Albert M. Young, Roy R. Yu
  • Publication number: 20140351783
    Abstract: A first signal is transmitted through a first path. A computing device determines a signal propagation time of the first signal. The computing device transmits a second signal through a second path, wherein the second path includes the second signal traversing across at least one interconnecting structure. The computing device determines a signal propagation time of the second signal. The computing device determines a propagation time difference between the signal propagation time of the first signal and the signal propagation time of the second signal. The computing device adjusts a clock based on the determined propagation time difference.
    Type: Application
    Filed: May 23, 2013
    Publication date: November 27, 2014
    Applicant: International Business Machines Corporation
    Inventors: Anand Haridass, Subramanian S. Iyer, Saravanan Sethuraman, Ming Yin
  • Publication number: 20140256130
    Abstract: A method for printing a wafer ID on a wafer, the method comprises identifying a wafer ID on a back side of the wafer. Subsequently, etching a plurality of recesses, consistent in size with chip features of the wafer, into the front side of the wafer, such that the plurality of recesses depicts the wafer ID. The method further comprises filling the recesses with a metal.
    Type: Application
    Filed: March 5, 2013
    Publication date: September 11, 2014
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Mukta G. Farooq, Robert Hannon, Subramanian S. Iyer, Kevin S. Petrarca, Stuart A. Sieg
  • Patent number: 8822141
    Abstract: A method for printing a wafer ID on a wafer, the method comprises identifying a wafer ID on a back side of the wafer. Subsequently, etching a plurality of recesses, consistent in size with chip features of the wafer, into the front side of the wafer, such that the plurality of recesses depicts the wafer ID. The method further comprises filling the recesses with a metal.
    Type: Grant
    Filed: March 5, 2013
    Date of Patent: September 2, 2014
    Assignee: International Business Machines Corporation
    Inventors: Mukta G. Farooq, Robert Hannon, Subramanian S. Iyer, Kevin S. Petrarca, Stuart A. Sieg
  • Publication number: 20140165141
    Abstract: Embodiments of the present invention provide an authenticating service of a chip having an intrinsic identifier (ID). In a typical embodiment, an authenticating device is provided that includes an identification (ID) engine, a self-test engine, and an intrinsic component. The intrinsic component is associated with a chip and includes an intrinsic feature. The self-test engine retrieves the intrinsic feature and communicates it to the identification engine. The identification engine receives the intrinsic feature, generates a first authentication value using the intrinsic feature, and stores the authentication value in memory. The self-test engine generates a second authentication value using an authentication challenge. The identification engine includes a compare circuitry that compares the first authentication value and the second authentication value and generates an authentication output value based on the results of the compare of the two values.
    Type: Application
    Filed: December 7, 2012
    Publication date: June 12, 2014
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Srivatsan Chellappa, Subramanian S. Iyer, Toshiaki Kirihata, Sami Rosenblatt
  • Patent number: 8738167
    Abstract: A method is provided for fabricating a 3D integrated circuit structure. According to the method, a first active circuitry layer wafer is provided. The first active circuitry layer wafer comprises a P+ portion covered by a P? layer, and the P? layer includes active circuitry. The first active circuitry layer wafer is bonded face down to an interface wafer that includes a first wiring layer, and then the P+ portion of the first active circuitry layer wafer is selectively removed with respect to the P? layer of the first active circuitry layer wafer. Next, a wiring layer is fabricated on the backside of the P? layer. Also provided are a non-transitory computer readable medium encoded with a program for fabricating a 3D integrated circuit structure, and a 3D integrated circuit structure.
    Type: Grant
    Filed: February 16, 2012
    Date of Patent: May 27, 2014
    Assignee: International Business Machines Corporation
    Inventors: Mukta G. Farooq, Robert Hannon, Subramanian S. Iyer, Steven J. Koester, Sampath Purushothaman, Roy R. Yu
  • Patent number: 8674515
    Abstract: A structure of connecting at least two integrated circuits in a 3D arrangement by a metal-filled through silicon via which simultaneously connects a connection pad in a first integrated circuit and a connection pad in a second integrated circuit.
    Type: Grant
    Filed: February 1, 2012
    Date of Patent: March 18, 2014
    Assignee: International Business Machines Corporation
    Inventors: Mukta G. Farooq, Subramanian S. Iyer, Steven J. Koester, Huilong Zhu
  • Patent number: 8664081
    Abstract: A computer readable medium is provided that is encoded with a program comprising instructions for performing a method for fabricating a 3D integrated circuit structure. Provided are an interface wafer including a first wiring layer and through-silicon vias, and a first active circuitry layer wafer including active circuitry. The first active circuitry layer wafer is bonded to the interface wafer. Then, a first portion of the first active circuitry layer wafer is removed such that a second portion remains attached to the interface wafer. A stack structure including the interface wafer and the second portion of the first active circuitry layer wafer is bonded to a base wafer. Next, the interface wafer is thinned so as to form an interface layer, and metallizations coupled through the through-silicon vias in the interface layer to the first wiring layer are formed on the interface layer.
    Type: Grant
    Filed: August 10, 2012
    Date of Patent: March 4, 2014
    Assignee: International Business Machines Corporation
    Inventors: Mukta G. Farooq, Robert Hannon, Subramanian S. Iyer, Steven J. Koester, Fei Liu, Sampath Purushothaman, Albert M. Young, Roy R. Yu
  • Patent number: 8658535
    Abstract: The present disclosure provides a thermo-mechanically reliable copper TSV and a technique to form such TSV during BEOL processing. The TSV constitutes an annular trench which extends through the semiconductor substrate. The substrate defines the inner and outer sidewalls of the trench, which sidewalls are separated by a distance within the range of 5 to 10 microns. A conductive path comprising copper or a copper alloy extends within said trench from an upper surface of said first dielectric layer through said substrate. The substrate thickness can be 60 microns or less. A dielectric layer having interconnect metallization conductively connected to the conductive path is formed directly over said annular trench.
    Type: Grant
    Filed: May 9, 2013
    Date of Patent: February 25, 2014
    Assignee: International Business Machines Corporation
    Inventors: Paul S. Andry, Mukta G. Rarooq, Robert Hannon, Subramanian S. Iyer, Emily R. Kinser, Comelia K. Tsang, Richard P. Volant
  • Patent number: 8637958
    Abstract: A structure and method for forming isolation and a buried plate for a trench capacitor is disclosed. Embodiments of the structure comprise an epitaxial layer serving as the buried plate, and a bounded deep trench isolation area serving to isolate one or more deep trench structures. Embodiments of the method comprise angular implanting of the deep trench isolation area to form a P region at the base of the deep trench isolation area that serves as an anti-punch through implant.
    Type: Grant
    Filed: September 14, 2012
    Date of Patent: January 28, 2014
    Assignee: International Business Machines Corporation
    Inventors: Abhishek Dube, Subramanian S. Iyer, Babar Ali Khan, Oh-jung Kwon, Junedong Lee, Paul C. Parries, Chengwen Pei, Gerd Pfeiffer, Ravi Todi, Geng Wang
  • Patent number: 8629017
    Abstract: A memory device is provided that in one embodiment includes a trench capacitor located in a semiconductor substrate including an outer electrode provided by the semiconductor substrate, an inner electrode provided by a conductive fill material, and a node dielectric layer located between the outer electrode and the inner electrode; and a semiconductor device positioned centrally over the trench capacitor. The semiconductor device includes a source region, a drain region, and a gate structure, in which the semiconductor device is formed on a semiconductor layer that is separated from the semiconductor substrate by a dielectric layer. A first contact is present extending from an upper surface of the semiconductor layer into electrical contact with the semiconductor substrate, and a second contact from the drain region of the semiconductor device in electrical contact to the conductive material within the at least one trench.
    Type: Grant
    Filed: March 12, 2012
    Date of Patent: January 14, 2014
    Assignee: International Business Machines Corporation
    Inventors: Chengwen Pei, Kangguo Cheng, Herbert L. Ho, Subramanian S. Iyer, Byeong Y. Kim, Geng Wang, Huilong Zhu
  • Patent number: 8629553
    Abstract: A method is provided for fabricating a 3D integrated circuit structure. According to the method, a first active circuitry layer wafer is provided. The first active circuitry layer wafer comprises a P+ portion covered by a P? layer, and the P? layer includes active circuitry. The first active circuitry layer wafer is bonded face down to an interface wafer that includes a first wiring layer, and then the P+ portion of the first active circuitry layer wafer is selectively removed with respect to the P? layer of the first active circuitry layer wafer. Next, a wiring layer is fabricated on the backside of the P? layer. Also provided are a tangible computer readable medium encoded with a program for fabricating a 3D integrated circuit structure, and a 3D integrated circuit structure.
    Type: Grant
    Filed: February 16, 2012
    Date of Patent: January 14, 2014
    Assignee: International Business Machines Corporation
    Inventors: Mukta G. Farooq, Robert Hannon, Subramanian S. Iyer, Steven J. Koester, Sampath Purushothaman, Roy R. Yu
  • Patent number: 8590010
    Abstract: A random intrinsic chip ID generation employs a retention fail signature. A 1st and 2nd ID are generated using testing settings with a 1st setting more restrictive than the 2nd, creating more fails in the 1st ID bit string that includes 2nd ID bit string. A retention pause time controls the number of retention fails, adjusted by a BIST engine, wherein the fail numbers satisfy a predetermined fail target. Verification confirms whether the 1st ID includes the 2nd ID bit string, the ID being the one used for authentication. Authentication is enabled by a 3rd ID with intermediate condition such that 1st ID includes 3rd ID bit string and 3rd ID includes 2nd ID bit string. The intermediate condition includes a guard-band to eliminate bit instability problem near the 1st and 2nd ID boundary. The intermediate condition is changed at each ID read operation, resulting in a more secure identification.
    Type: Grant
    Filed: November 22, 2011
    Date of Patent: November 19, 2013
    Assignee: International Business Machines Corporation
    Inventors: Daniel J. Fainstein, Alberto Cestero, Subramanian S. Iyer, Toshiaki Kirihata, Norman W. Robson, Sami Rosenblatt
  • Publication number: 20130244420
    Abstract: The present disclosure provides a thermo-mechanically reliable copper TSV and a technique to form such TSV during BEOL processing. The TSV constitutes an annular trench which extends through the semiconductor substrate. The substrate defines the inner and outer sidewalls of the trench, which sidewalls are separated by a distance within the range of 5 to 10 microns. A conductive path comprising copper or a copper alloy extends within said trench from an upper surface of said first dielectric layer through said substrate. The substrate thickness can be 60 microns or less. A dielectric layer having interconnect metallization conductively connected to the conductive path is formed directly over said annular trench.
    Type: Application
    Filed: May 9, 2013
    Publication date: September 19, 2013
    Applicant: International Business Machines Corporation
    Inventors: Paul S. Andry, Mukta G. Farooq, Robert Hannon, Subramanian S. Iyer, Emily R. Kinser, Cornelia K. Tsang, Richard P. Volant
  • Patent number: 8492869
    Abstract: A 3D integrated circuit structure is provided. The 3D integrated circuit structure includes an interface wafer including a first wiring layer, a first active circuitry layer including active circuitry, and a wafer including active circuitry. The first active circuitry layer is bonded face down to the interface wafer, and the wafer is bonded face down to the first active circuitry layer. The first active circuitry layer is lower-cost than the wafer.
    Type: Grant
    Filed: August 10, 2012
    Date of Patent: July 23, 2013
    Assignee: International Business Machines Corporation
    Inventors: Mukta G. Farooq, Robert Hannon, Subramanian S. Iyer, Steven J. Koester, Fei Liu, Sampath Purushothaman, Albert M. Young, Roy R. Yu
  • Patent number: 8487425
    Abstract: The present disclosure provides a thermo-mechanically reliable copper TSV and a technique to form such TSV during BEOL processing. The TSV constitutes an annular trench which extends through the semiconductor substrate. The substrate defines the inner and outer sidewalls of the trench, which sidewalls are separated by a distance within the range of 5 to 10 microns. A conductive path comprising copper or a copper alloy extends within said trench from an upper surface of said first dielectric layer through said substrate. The substrate thickness can be 60 microns or less. A dielectric layer having interconnect metallization conductively connected to the conductive path is formed directly over said annular trench.
    Type: Grant
    Filed: June 23, 2011
    Date of Patent: July 16, 2013
    Assignee: International Business Machines Corporation
    Inventors: Paul S Andry, Mukta G Farooq, Robert Hannon, Subramanian S Iyer, Emily R Kinser, Cornelia K Tsang, Richard P Volant