Patents by Inventor Sivananda Kanakasabapathy

Sivananda Kanakasabapathy 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: 20090065817
    Abstract: The present invention relates to semiconductor devices, and more particularly to a process and structure for removing a dielectric spacer selective to a surface of a semiconductor substrate with substantially no removal of the semiconductor substrate. The method of the present invention can be integrated into a conventional CMOS processing scheme or into a conventional BiCMOS processing scheme. The method includes forming a field effect transistor on a semiconductor substrate, the FET comprising a dielectric spacer and the gate structure, the dielectric spacer located adjacent a sidewall of the gate structure and over a source/drain region in the semiconductor substrate; depositing a first nitride layer over the FET; and removing the nitride layer and the dielectric spacer selective to the semiconductor substrate with substantially no removal of the semiconductor substrate.
    Type: Application
    Filed: September 10, 2007
    Publication date: March 12, 2009
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Eduard A. Cartier, Rashmi Jha, Sivananda Kanakasabapathy, Xi Li, Renee T. Mo, Vijay Narayanan, Vamsi Paruchuri, Mark T. Robson, Kathryn T. Schonenberg, Michelle L. Steen, Richard Wise, Ying Zhang
  • Publication number: 20090047784
    Abstract: A method for fabricating a microelectronic structure provides for forming a backfilling material layer at least laterally adjacent, and preferably laterally adjoining, a resist layer located over a substrate. Preferably, the resist layer comprises a surface treated resist layer. Optionally, the backfilling material layer may be surface treated similarly to the surface treated resist layer. Under such circumstances: (1) surface portions of the backfilling material layer and resist layer; and (2) remaining portions of the backfilling material layer and resist layer, may be sequentially stripped using a two step etch method, such as a two step plasma etch method. Alternatively, a surface portion of the surface treated resist layer only may be stripped while using a first etch method, and the remaining portions of the resist layer and backfilling material layer may be planarized prior to being simultaneously stripped while using a second etch method.
    Type: Application
    Filed: August 16, 2007
    Publication date: February 19, 2009
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Nicholas C.M. Fuller, Sivananda Kanakasabapathy, Ying Zhang
  • Patent number: 7442647
    Abstract: A structure and method for fabricating a top strap in a magnetic random access memory, MRAM, comprising a damascene process forming a trench in a dielectric layer and resulting in a metal conductor clad on three sides by an inverted U-shape trench liner and cap made up of three layers consisting of a stack of a ferromagnetic material sandwiched between two layers of a refractory metal or an alloy of a refractory metal. First the two sidewalls of the trench are formed with the cladding layer, followed by filling the trench with the metal conductor. In preparing the structure for the capping layer, the metal conductor is recessed with an etch that is selective to the metal conductor over the sidewall stack. This preparation may be performed on selected metal filled trenches and blocked on others, such that after a final polishing step, only those metal conductors that received the recess operation will have the capping layer.
    Type: Grant
    Filed: March 5, 2008
    Date of Patent: October 28, 2008
    Assignee: International Business Machines Corporation
    Inventors: Sivananda Kanakasabapathy, Eugene J. O'Sullivan, Michael Christopher Gaidis, Michael Francis Lofaro
  • Publication number: 20080211055
    Abstract: Novel methods for reliably and reproducibly forming magnetic tunnel junctions in integrated circuits are described. In accordance with aspects of the invention, sidewall spacer features are utilized during the processing of the film stack. Advantageously, these sidewall spacer features create a tapered masking feature which helps to avoid byproduct redeposition during the etching of the MTJ film stack, thereby improving process yield. Moreover, the sidewall spacer features may be used as encapsulating layers during subsequent processing steps and as vertical contacts to higher levels of metallization.
    Type: Application
    Filed: May 15, 2008
    Publication date: September 4, 2008
    Applicant: International Business Machines Corporation
    Inventors: Solomon Assefa, Michael C. Gaidis, Sivananda Kanakasabapathy, John P. Hummel, David W. Abraham
  • Publication number: 20080198647
    Abstract: In one embodiment, the invention is a method and apparatus for bitline and contact via integration in magnetic random access memory arrays. One embodiment of a magnetic random access memory according to the present invention includes a magnetic tunnel junction and a top wire that surrounds the magnetic tunnel junction on at least three sides.
    Type: Application
    Filed: February 21, 2007
    Publication date: August 21, 2008
    Inventors: Sivananda Kanakasabapathy, Michael C. Gaidis
  • Publication number: 20080043379
    Abstract: Techniques for forming a magnetic device are provided. In one aspect, a magnetic device includes a magnetic tunnel junction and a dielectric layer formed over at least a portion of the magnetic tunnel junction. The dielectric layer is configured to have an underlayer proximate to the magnetic tunnel junction, and an overlayer on a side of the underlayer opposite the magnetic tunnel junction. The magnetic device further includes a via hole running substantially vertically through the dielectric layer and being self-aligned with the magnetic tunnel junction.
    Type: Application
    Filed: October 29, 2007
    Publication date: February 21, 2008
    Applicant: International Business Machines Corporation
    Inventors: Sivananda Kanakasabapathy, Michael Gaidis
  • Publication number: 20070210394
    Abstract: A method for implementing alignment of a semiconductor device structure includes forming first and second sets of alignment marks within a lower level of the structure, the second set of alignment marks adjacent the first set of alignment marks. An opaque layer is formed over the lower level, including the first and second sets of alignment marks. A portion of the opaque layer corresponding to the location of said first set of alignment marks is opened so as to render the first set optically visible while the second set of alignment marks initially remains covered by the opaque layer. The opaque layer is patterned using the optically visible first set of alignment marks, wherein the second set of alignment marks remain available for subsequent alignment operations in the event the first set becomes damaged during patterning of the opaque layer.
    Type: Application
    Filed: March 7, 2006
    Publication date: September 13, 2007
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Sivananda Kanakasabapathy, David Abraham
  • Publication number: 20070166840
    Abstract: Novel methods for reliably and reproducibly forming magnetic tunnel junctions in integrated circuits are described. In accordance with aspects of the invention, sidewall spacer features are utilized during the processing of the film stack. Advantageously, these sidewall spacer features create a tapered masking feature which helps to avoid byproduct redeposition during the etching of the MTJ film stack, thereby improving process yield. Moreover, the sidewall spacer features may be used as encapsulating layers during subsequent processing steps and as vertical contacts to higher levels of metallization.
    Type: Application
    Filed: January 18, 2006
    Publication date: July 19, 2007
    Applicant: International Business Machines Corporation
    Inventors: Solomon Assefa, Michael Gaidis, Sivananda Kanakasabapathy, John Hummel, David Abraham
  • Publication number: 20070048950
    Abstract: Techniques for forming a magnetic device are provided. In one aspect, a method of forming a via hole self-aligned with a magnetic device comprises the following steps. A dielectric layer is formed over at least a portion of the magnetic device. The dielectric layer is configured to have an underlayer proximate to the magnetic device which comprises a first material, and an overlayer on a side of the underlayer opposite the magnetic device which comprises a second material. The first material is different from the second material. In a first etching phase, a first etchant is used to etch the dielectric layer, beginning with the overlayer, and through the overlayer. In a second etching phase, a second etchant which is selective for etching the underlayer is used to etch the dielectric layer through the underlayer.
    Type: Application
    Filed: August 23, 2005
    Publication date: March 1, 2007
    Applicant: International Business Machines Corporation
    Inventors: Sivananda Kanakasabapathy, Michael Gaidis
  • Publication number: 20070020934
    Abstract: Techniques for magnetic device fabrication are provided. In one aspect, a method of patterning at least one, e.g., nonvolatile, material comprises the following steps. A hard mask structure is formed on at least one surface of the material to be patterned. The hard mask structure is configured to have a base, proximate to the material, and a top opposite the base. The base has one or more lateral dimensions that are greater than one or more lateral dimensions of the top of the hard mask structure, such that at least one portion of the base extends out laterally a substantial distance beyond the top. The top of the hard mask structure is at a greater vertical distance from the material being etched than the base. The material is etched.
    Type: Application
    Filed: July 8, 2005
    Publication date: January 25, 2007
    Applicant: International Business Machines Corporation
    Inventors: Michael Gaidis, Sivananda Kanakasabapathy, Eugene O'Sullivan
  • Publication number: 20060092688
    Abstract: Techniques for improving magnetic device performance are provided. In one aspect, a magnetic device, e.g., a magnetic random access memory device, is provided which comprises a plurality of current carrying lines; and two or more adjacent stacked magnetic toggling devices sharing at least one of the plurality of current carrying lines in common and positioned therebetween. The magnetic device is configured such that at least one of the adjacent magnetic toggling devices toggles mutually exclusively of another of the adjacent magnetic toggling devices. In an exemplary embodiment, the magnetic device comprises a plurality of levels with each of the adjacent stacked magnetic toggling devices residing in a different level.
    Type: Application
    Filed: October 29, 2004
    Publication date: May 4, 2006
    Applicant: International Business Machines Corporation
    Inventors: Sivananda Kanakasabapathy, Yu Lu, Michael Gaidis
  • Publication number: 20050274997
    Abstract: In an MRAM cell, the writing current is encased in a low-reluctance material that is treated in one of several ways to render the material closest to the storage element ineffective to carry magnetic flux, thereby establishing a horseshoe-shaped cross section that focuses the flux toward the storage element.
    Type: Application
    Filed: June 15, 2004
    Publication date: December 15, 2005
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Michael Gaidis, Phillip Trouilloud, Sivananda Kanakasabapathy, David Abraham
  • Publication number: 20050254180
    Abstract: A a magnetic random access memory (MRAM) device includes a cap layer formed over a magnetic tunnel junction (MTJ) stack layer, an etch stop layer formed over the first cap layer, and a hardmask layer formed over the etch stop layer. The etch stop layer is selected from a material such that an etch chemistry used for removing the hardmask layer has selectivity against etching the etch stop layer material.
    Type: Application
    Filed: May 14, 2004
    Publication date: November 17, 2005
    Applicants: INTERNATIONAL BUSINESS MACHINES CORPORATION, INFINEON TECHNOLOGIES NORTH AMERICA CORP.
    Inventors: Sivananda Kanakasabapathy, David Abraham, Ulrich Klostermann
  • Publication number: 20050079683
    Abstract: A method for aligning an opaque, active device in a semiconductor structure includes forming an opaque layer over an optically transparent layer formed on a lower metallization level, the lower metallization level including one or more alignment marks formed therein. A portion of the opaque layer is patterned and opened corresponding to the location of the one or more alignment marks in the lower metallization level so as to render the one or more alignment marks optically visible. The opaque layer is then patterned with respect to the lower metallization level, using the optically visible one or more alignment marks.
    Type: Application
    Filed: October 13, 2003
    Publication date: April 14, 2005
    Applicants: INTERNATIONAL BUSINESS MACHINES CORPORATION, INFINEON TECHNOLOGIES NORTH AMERICA CORP.
    Inventors: Chandrasekhar Sarma, Sivananda Kanakasabapathy, Ihar Kasko, Greg Costrini, John Hummel, Michael Gaidis