Patents by Inventor Mahadevaiyer Krishnan

Mahadevaiyer Krishnan 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: 20040113279
    Abstract: An integrated circuit structure is disclosed that has a layer of logical and functional devices and an interconnection layer above the layer of logical and functional devices. The interconnection layer has a substrate, conductive features within the substrate and caps positioned only above the conductive features.
    Type: Application
    Filed: December 16, 2002
    Publication date: June 17, 2004
    Applicant: International Business Machines Corporation
    Inventors: Shyng-Tsong Chen, Timothy J. Dalton, Kenneth M. Davis, Chao-Kun Hu, Fen F. Jamin, Steffen K. Kaldor, Mahadevaiyer Krishnan, Kaushik Kumar, Michael F. Lofaro, Sandra G. Malhotra, Chandrasekhar Narayan, David L. Rath, Judith M. Rubino, Katherine L. Saenger, Andrew H. Simon, Sean P.E. Smith, Wei-tsu Tseng
  • Patent number: 6743642
    Abstract: A method for manufacturing a magnetoresistive random access memory (MRAM) cell is disclosed, which alleviates the problem of Neel coupling caused by roughness in the interface between the tunnel junction layer and the magnetic layers. The method includes depositing first and second barrier layers on the conductor, wherein the first barrier layer has a polish rate different from that of the second barrier layer. The second barrier layer is then essentially removed by chemical mechanical polishing (CMP), leaving a very smooth and uniform first barrier layer. When the magnetic stack is then formed on the polished first barrier layer, interfacial roughness is not translated to the tunnel junction layer, and no corruption of magnetization is experienced.
    Type: Grant
    Filed: November 6, 2002
    Date of Patent: June 1, 2004
    Assignees: International Business Machines Corporation, Infineon AG
    Inventors: Gregory Costrini, John Hummel, Kia-Seng Low, Mahadevaiyer Krishnan
  • Publication number: 20040094511
    Abstract: A method for controlling the shape of copper features, having the following steps:
    Type: Application
    Filed: November 20, 2002
    Publication date: May 20, 2004
    Applicant: International Business Machines Corporation
    Inventors: Soon-Cheon Seo, Wei-Tsu Tseng, Darryl D. Restaino, James E. Fluegel, Richard O. Henry, John M. Cotte, Mahadevaiyer Krishnan, Hariklia Deligianni, Philippe Mark Vereecken, Stephen E. Greco
  • Publication number: 20040087135
    Abstract: A structure incorporates very low dielectric constant (k) insulators with copper wiring to achieve high performance interconnects. The wiring is supported by a relatively durable low k dielectric such as SiLk or SiO2 and a very low k and less robust gap fill dielectric is disposed in the remainder of the structure, so that the structure combines a durable layer for strength with a very low k dielectric for interconnect electrical performance.
    Type: Application
    Filed: October 24, 2002
    Publication date: May 6, 2004
    Applicant: International Business Machines Corporation
    Inventors: Donald F. Canaperi, Timothy J. Dalton, Stephen M. Gates, Mahadevaiyer Krishnan, Satya V. Nitta, Sampath Purushothaman, Sean P.E. Smith
  • Publication number: 20040087038
    Abstract: A method for manufacturing a magnetoresistive random access memory (MRAM) cell is disclosed, which alleviates the problem of Neel coupling caused by roughness in the interface between the tunnel junction layer and the magnetic layers. The method comprises depositing first and second barrier layers on the conductor, wherein the first barrier layer has a polish rate different from that of the second barrier layer. The second barrier layer is then essentially removed by chemical mechanical polishing (CMP), leaving a very smooth and uniform first barrier layer. When the magnetic stack is then formed on the polished first barrier layer, interfacial roughness is not translated to the tunnel junction layer, and no corruption of magnetization is experienced.
    Type: Application
    Filed: November 6, 2002
    Publication date: May 6, 2004
    Applicants: INTERNATIONAL BUSINESS MACHINES CORPORATION, INFINEON TECHNOLOGIES NORTH AMERICA CORP.
    Inventors: Gregory Costrini, John Hummel, Kia-Seng Low, Mahadevaiyer Krishnan
  • Patent number: 6656369
    Abstract: A scanning probe microscope probe is formed by depositing probe material in a mold that has a cavity in a shape and of a size of the desired form of the scanning probe microscope probe that is being fabricated. In the preferred embodiment, the cavity is formed by lithographically defining, in the body of the mold, the shape and the size of the desired scanning probe microscope probe and etching the body of the mold to form the cavity. Prior to depositing the probe material in the cavity in the mold, the cavity is lined with a release layer which, upon activation after the probe has been formed, permits removal of the probe.
    Type: Grant
    Filed: January 17, 2002
    Date of Patent: December 2, 2003
    Assignee: International Business Machines Corporation
    Inventors: Mahadevaiyer Krishnan, Mark E. Lagus, Kevin S. Petrarca, James G. Ryan, Richard P. Volant
  • Publication number: 20030211698
    Abstract: A method is described for fabricating an encapsulated metal structure in a feature formed in a substrate. The sidewalls and bottom of the feature are covered by a barrier layer and the feature is filled with metal, preferably by electroplating. A recess is formed in the metal, and an additional barrier layer is deposited, covering the top surface of the metal and contacting the first barrier layer. The additional barrier layer is planarized, preferably by chemical-mechanical polishing. The method may be used in fabricating a MIM capacitor, with the encapsulated metal structure serving as the lower plate of the capacitor. A second substrate layer is deposited on the top surface of the substrate, with an opening overlying the encapsulated metal structure. A dielectric layer is deposited in the opening, covering the encapsulated metal structure at the bottom thereof. An additional layer, serving as the upper plate of the capacitor, is deposited to cover the dielectric layer and to fill the opening.
    Type: Application
    Filed: April 7, 2003
    Publication date: November 13, 2003
    Inventors: Kevin S. Petrarca, Donald Canaperi, Mahadevaiyer Krishnan, Kenneth Jay Stein, Richard P. Volant
  • Patent number: 6597068
    Abstract: A method is described for fabricating an encapsulated metal structure in a feature formed in a substrate. The sidewalls and bottom of the feature are covered by a barrier layer and the feature is filled with metal, preferably by electroplating. A recess is formed in the metal, and an additional barrier layer is deposited, covering the top surface of the metal and contacting the first barrier layer. The additional barrier layer is planarized, preferably by chemical-mechanical polishing. The method may be used in fabricating a MIM capacitor, with the encapsulated metal structure serving as the lower plate of the capacitor. A second substrate layer is deposited on the top surface of the substrate, with an opening overlying the encapsulated metal structure. A dielectric layer is deposited in the opening, covering the encapsulated metal structure at the bottom thereof. An additional layer, serving as the upper plate of the capacitor, is deposited to cover the dielectric layer and to fill the opening.
    Type: Grant
    Filed: December 28, 2001
    Date of Patent: July 22, 2003
    Assignee: International Business Machines Corporation
    Inventors: Kevin S. Petrarca, Donald Canaperi, Mahadevaiyer Krishnan, Kenneth Jay Stein, Richard P. Volant
  • Publication number: 20030132191
    Abstract: A scanning probe microscope probe is formed by depositing probe material in a mold that has a cavity in a shape and of a size of the desired form of the scanning probe microscope probe that is being fabricated. In the preferred embodiment, the cavity is formed by lithographically defining, in the body of the mold, the shape and the size of the desired scanning probe microscope probe and etching the body of the mold to form the cavity. Prior to depositing the probe material in the cavity in the mold, the cavity is lined with a release layer which, upon activation after the probe has been formed, permits removal of the probe.
    Type: Application
    Filed: January 17, 2002
    Publication date: July 17, 2003
    Applicant: International Business Machines Corporation
    Inventors: Mahadevaiyer Krishnan, Mark E. Lagus, Kevin S. Petrarca, James G. Ryan, Richard P. Volant
  • Publication number: 20030073593
    Abstract: Slurry compositions comprising an oxidizing agent, optionally a copper corrosion inhibitor, abrasive particles; surface active agent, a service of chloride and a source of sulfate ions.
    Type: Application
    Filed: August 30, 2002
    Publication date: April 17, 2003
    Inventors: Michael Todd Brigham, Donald Francis Canaperi, Michael A. Cobb, William Cote, Kenneth M. Davis, Scott Alan Estes, Edward Jack Gordon, James Willard Hannah, Mahadevaiyer Krishnan, Michael F. Lofaro, Michael Joseph MacDonald, Dean Allen Schaffer, George James Slusser, James A. Tornello, Eric Jeffrey White
  • Patent number: 6503834
    Abstract: The invention provides a process to increase the reliability of BEOL interconnects. The process comprises forming an array of conductors on a dielectric layer on a wafer substrate, polishing the upper surface so that the surfaces of the conductors are substantially co-planar with the upper surface of the dielectric layer, forming an alloy film on the upper surfaces of the conductors, and brush cleaning the upper surfaces of the conductors and the dielectric layer.
    Type: Grant
    Filed: October 3, 2000
    Date of Patent: January 7, 2003
    Assignee: International Business Machines Corp.
    Inventors: Xiaomeng Chen, Mahadevaiyer Krishnan, Judith M. Rubino, Carlos J. Sambucetti, Soon-Cheon Seo, James A. Tornello
  • Publication number: 20020068431
    Abstract: A method is described for fabricating an encapsulated metal structure in a feature formed in a substrate. The sidewalls and bottom of the feature are covered by a barrier layer and the feature is filled with metal, preferably by electroplating. A recess is formed in the metal, and an additional barrier layer is deposited, covering the top surface of the metal and contacting the first barrier layer. The additional barrier layer is planarized, preferably by chemical-mechanical polishing. The method may be used in fabricating a MIM capacitor, with the encapsulated metal structure serving as the lower plate of the capacitor. A second substrate layer is deposited on the top surface of the substrate, with an opening overlying the encapsulated metal structure. A dielectric layer is deposited in the opening, covering the encapsulated metal structure at the bottom thereof. An additional layer, serving as the upper plate of the capacitor, is deposited to cover the dielectric layer and to fill the opening.
    Type: Application
    Filed: December 28, 2001
    Publication date: June 6, 2002
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Kevin S. Petrarca, Donald Canaperi, Mahadevaiyer Krishnan, Kenneth Jay Stein, Richard P. Volant
  • Patent number: 6368953
    Abstract: A method is described for fabricating an encapsulated metal structure in a feature formed in a substrate. The sidewalls and bottom of the feature are covered by a barrier layer and the feature is filled with metal, preferably by electroplating. A recess is formed in the metal, and an additional barrier layer is deposited, covering the top surface of the metal and contacting the first barrier layer. The additional barrier layer is planarized, preferably by chemical-mechanical polishing. The method may be used in fabricating a MIM capacitor, with the encapsulated metal structure serving as the lower plate of the capacitor. A second substrate layer is deposited on the top surface of the substrate, with an opening overlying the encapsulated metal structure. A dielectric layer is deposited in the opening, covering the encapsulated metal structure at the bottom thereof. An additional layer, serving as the upper plate of the capacitor, is deposited to cover the dielectric layer and to fill the opening.
    Type: Grant
    Filed: May 9, 2000
    Date of Patent: April 9, 2002
    Assignee: International Business Machines Corporation
    Inventors: Kevin S. Petrarca, Donald Canaperi, Mahadevaiyer Krishnan, Kenneth Jay Stein, Richard P. Volant
  • Patent number: 6361402
    Abstract: A method for polishing an object having a layer of photoresist, the method, employing the following steps: a) applying a layer of slurry on an a layer of photoresist on an object having a first and a second side, the layer of photoresist on one of the first and second side, the object having a center axis perpendicular to the first and second side; b) contacting the layer of slurry with a pad having a first and second side, the first side of the pad exerting a force on the slurry.
    Type: Grant
    Filed: October 26, 1999
    Date of Patent: March 26, 2002
    Assignee: International Business Machines Corporation
    Inventors: Donald F. Canaperi, Rangarajan Jagannathan, Mahadevaiyer Krishnan, Max G. Levy, Uma Satyendra, Matthew Sendelbach, James A. Tornello, William Wille
  • Patent number: 6358832
    Abstract: A damascene interconnect containing a dual etch stop/diffusion barrier. The conductive material of the damascene interconnect is capped with a conductive metal diffusion barrier cap, typically using electroless deposition, and, optionally, with a dielectric etch-stop layer. An optional chemical mechanical polish-stop layer may also be present. The different methods of the invention allow the CMP stop, reactive-ion etch stop, and metal diffusion barrier requirements of the different layers to be decoupled. A preferred conductive material is copper.
    Type: Grant
    Filed: August 18, 2000
    Date of Patent: March 19, 2002
    Assignee: International Business Machines Corporation
    Inventors: Daniel C. Edelstein, Timothy J. Dalton, John G. Gaudiello, Mahadevaiyer Krishnan, Sandra G. Malhotra, Maurice McGlashan-Powell, Eugene J. O'Sullivan, Carlos J. Sambucetti
  • Patent number: 6348076
    Abstract: Slurry compositions comprising an oxidizing agent, copper corrosion inhibitor, abrasive particles; surface active agent and polyelectrolyte are useful for polishing or planarizing chip interconnect/wiring material such as Al, W and especially Cu.
    Type: Grant
    Filed: December 28, 1999
    Date of Patent: February 19, 2002
    Assignee: International Business Machines Corporation
    Inventors: Donald F. Canaperi, William J. Cote, Paul Feeney, Mahadevaiyer Krishnan, Joyce C. Liu, Michael F. Lofaro, Philip Murphy, Eric Jeffrey White
  • Patent number: 6190237
    Abstract: A slurry containing abrasive particles and a pH buffering component comprising at least one acid or salt thereof and at least one base is especially useful for polishing surfaces, including those used in microelectronics.
    Type: Grant
    Filed: November 6, 1997
    Date of Patent: February 20, 2001
    Assignee: International Business Machines Corporation
    Inventors: Cuc Kim Huynh, Mahadevaiyer Krishnan, Michael Joseph MacDonald, Mark Peter Murray
  • Patent number: 6153935
    Abstract: A damascene interconnect containing a dual etch stop/diffusion barrier. The conductive material of the damascene interconnect is capped with a conductive metal diffusion barrier cap, typically using electroless deposition, and, optionally, with a dielectric etch-stop layer. An optional chemical mechanical polish-stop layer may also be present. The different methods of the invention allow the CMP stop, reactive-ion etch stop, and metal diffusion barrier requirements of the different layers to be decoupled. A preferred conductive material is copper.
    Type: Grant
    Filed: September 30, 1999
    Date of Patent: November 28, 2000
    Assignee: International Business Machines Corporation
    Inventors: Daniel C. Edelstein, Timothy J. Dalton, John G. Gaudiello, Mahadevaiyer Krishnan, Sandra G. Malhotra, Maurice McGlashan-Powell, Eugene J. O'Sullivan, Carlos J. Sambucetti
  • Patent number: 6114249
    Abstract: A colloidal silica slurry containing triethanolamine is used in a chemical mechanical polishing process to polish multiple material substrates, such as silicon wafers containing silicon oxide where a thin underlayer of silicon nitride is used as a stop layer. The colloidal silica slurry containing triethanolamine is capable of achieving an oxide to nitride selectivity during polishing up to a demonstrated ratio of 28:1.
    Type: Grant
    Filed: March 10, 1998
    Date of Patent: September 5, 2000
    Assignee: International Business Machines Corporation
    Inventors: Donald Francis Canaperi, Rangarajan Jagannathan, Mahadevaiyer Krishnan, Clifford Owen Morgan, Terrance Monte Wright
  • Patent number: 5635253
    Abstract: A replenishing solution for a cyanide-based electroless gold plating bath. The solution includes a gold(III) halide such as gold chloride, gold bromide, tetrachloroaurate (and its sodium, potassium, and ammonium salts), and tetrabromoaurate (and its sodium, potassium, and ammonium salts). The replenishing solution also may include an alkali (such as potassium hydroxide, sodium hydroxide, and ammonium hydroxide) to maintain the pH of the solution between 8 and 14. Also provided is a method of replenishing a cyanide-based electroless gold plating bath with the solution of the present invention.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: June 3, 1997
    Assignee: International Business Machines Corporation
    Inventors: Donald F. Canaperi, Rangarajan Jagannathan, Mahadevaiyer Krishnan