Patents by Inventor Kamalesh K. Srivastava

Kamalesh K. Srivastava 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: 20080157395
    Abstract: An interconnection structure suitable for flip-chip attachment of microelectronic device chips to packages, comprising a two, three or four layer ball-limiting metallurgy including an adhesion/reaction barrier layer, and having a solder wettable layer reactive with components of a tin-containing lead free solder, so that the solderable layer can be totally consumed during soldering, but a barrier layer remains after being placed in contact with the lead free solder during soldering. One or more lead-free solder balls is selectively situated on the solder wetting layer, the lead-free solder balls comprising tin as a predominant component and one or more alloying components.
    Type: Application
    Filed: December 28, 2006
    Publication date: July 3, 2008
    Inventors: Luc Belanger, Stephen L. Buchwalter, Leena Paivikki Buchwalter, Ajay P. Giri, Jonathan H. Griffith, Donald W. Henderson, Sung Kwon Kang, Eric H. Laine, Christian Lavoie, Paul A. Lauro, Valerie Anne Oberson, Da-Yuan Shih, Kamalesh K. Srivastava, Michael J. Sullivan
  • Publication number: 20080124939
    Abstract: An etchant which includes an aqueous solution of between about 30% and about 38% concentrated hydrogen peroxide, said percentages being by volume, based on the total volume of the solution; between about 3.5 ml and about 20 ml per liter of phosphoric acid; and an amount of potassium hydroxide to adjust the pH of the solution to between about 7.8 and about 9.1. The etchant is useful in removing a layer of an alloy of titanium and tungsten or a layer of tungsten from a precision surface.
    Type: Application
    Filed: November 28, 2006
    Publication date: May 29, 2008
    Applicant: International Business Machines Corporation
    Inventors: Krystyna Waleria Semkow, Anurag Jain, Kamalesh K. Srivastava
  • Publication number: 20080119056
    Abstract: A solution for wet etching a copper film within a ball limiting metallurgy (BLM) of a semiconductor device includes, in an exemplary embodiment, an ammonium persulfate etching agent, a potassium sulfate passivation agent for protecting a PbSn solder material, and a pH modifier for controlling the etch rate of the copper film.
    Type: Application
    Filed: November 16, 2006
    Publication date: May 22, 2008
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Carla A. Bailey, Tien-Jen Cheng, Robert Henry, Anurag Jain, Vall F. McLean, Krystyna W. Semkow, Kamalesh K. Srivastava
  • Patent number: 7144490
    Abstract: A method for selective electroplating of a semiconductor input/output (I/O) pad includes forming a titanium-tungsten (TiW) layer over a passivation layer on a semiconductor substrate, the TiW layer further extending into an opening formed in the passivation layer for exposing the I/O pad, such that the TiW layer covers sidewalls of the opening and a top surface of the I/O pad. A seed layer is formed over the TiW layer, and portions of the seed layer are selectively removed such that remaining seed layer material corresponds to a desired location of interconnect metallurgy for the I/O pad. At least one metal layer is electroplated over the remaining seed layer material, using the TiW layer as a conductive electroplating medium.
    Type: Grant
    Filed: November 18, 2003
    Date of Patent: December 5, 2006
    Assignee: International Business Machines Corporation
    Inventors: Tien-Jen Cheng, David E. Eichstadt, Jonathan H. Griffith, Sarah H. Knickerbocker, Rosemary A. Previti-Kelly, Roger A. Quon, Kamalesh K. Srivastava, Keith Kwong-Hon Wong
  • Patent number: 6995475
    Abstract: A method of forming wire bonds in (I/C) chips comprising: providing an I/C chip having a conductive pad for a wire bond with at least one layer of dielectric material overlying the pad; forming an opening through the dielectric material exposing a portion of said pad. Forming at least a first conductive layer on the exposed surface of the pad and on the surface of the opening. Forming a seed layer on the first conductive layer; applying a photoresist over the seed layer; exposing and developing the photoresist revealing the surface of the seed layer surrounding the opening; removing the exposed seed layer; removing the photoresist material in the opening revealing the seed layer. Plating at least one second layer of conductive material on the seed layer in the opening, and removing the first conductive layer on the dielectric layer around the opening. The invention also includes the resulting structure.
    Type: Grant
    Filed: September 18, 2003
    Date of Patent: February 7, 2006
    Assignee: International Business Machines Corporation
    Inventors: Julie C. Biggs, Tien-Jen Cheng, David E. Eichstadt, Lisa A. Fanti, Jonathan H. Griffith, Randolph F. Knarr, Sarah H. Knickerbocker, Kevin S. Petrarca, Roger A. Quon, Wolfgang Sauter, Kamalesh K. Srivastava, Richard P. Volant
  • Patent number: 6995084
    Abstract: A method for forming an interconnect structure for a semiconductor device includes defining a via in a passivation layer so as expose a top metal layer in the semiconductor device. A seed layer is formed over the passivation layer, sidewalls of the via, and the top metal layer. A barrier layer is formed over an exposed portion of the seed layer, the exposed portion defined by a first patterned opening. The semiconductor device is annealed so as to cause atoms from the barrier layer to diffuse into the seed layer thereunderneath, wherein the annealing causes diffused regions of the seed layer to have an altered electrical resistivity and electrode potential with respect to undiffused regions of the seed layer.
    Type: Grant
    Filed: March 17, 2004
    Date of Patent: February 7, 2006
    Assignee: International Business Machines Corporation
    Inventors: Kamalesh K. Srivastava, Subhash L. Shinde, Tien-Jen Cheng, Sarah H. Knickerbocker, Roger A. Quon, William E. Sablinski, Julie C. Biggs, David E. Eichstadt, Jonathan H. Griffith
  • Patent number: 6661100
    Abstract: A low impedance power distribution structure and method for substrate packaging of semiconductor chips containing very large scale integrated circuit (VLSI) circuits, such as microprocessors and associated memory, is presented. The power distribution structure incorporates under bump metallurgy (UBM) solder bump forming technology to produce not only solder bump connections that are vertically oriented, but also low impedance distribution wires that are horizontally oriented, and which provide electrical interconnection between various selected electrical contact points, such as solder bumps. These low impedance distribution wires introduce the benefits of low characteristic impedance to the substrate's power distribution structure.
    Type: Grant
    Filed: July 30, 2002
    Date of Patent: December 9, 2003
    Assignee: International Business Machines Corporation
    Inventors: Brent A. Anderson, Randolph F. Knarr, Sarah H. Knickerbocker, Edmund J. Sprogis, Kamalesh K. Srivastava
  • Patent number: 6622907
    Abstract: Start with a semiconductor substrate with contacts exposed through an insulating layer. Form a base over the contacts, with the base composed of at least one metal layer. Then form a conductive metal layer over the base. Form a mask over the top surface of the conductive metal layer with C4 solder bump openings therethrough with the shape of C4 solder bump images down to the surface of the conductive metal layer above the contacts. Etch away the exposed portions of the conductive metal layer below the C4 solder bump openings to form through holes in the conductive metal layer exposing C4 solder bump plating sites on the top surface of the base below the C4 solder bump openings with the conductive metal layer remaining intact on the periphery of the through holes at the C4 solder bump plating sites. As an option, form a barrier layer over the plating sites next.
    Type: Grant
    Filed: February 19, 2002
    Date of Patent: September 23, 2003
    Assignee: International Business Machines Corporation
    Inventors: Lisa A. Fanti, Randolph F. Knarr, Erik J. Roggeman, Kamalesh K. Srivastava
  • Publication number: 20030155408
    Abstract: Start with a semiconductor substrate with contacts exposed through an insulating layer. Form a base over the contacts, with the base composed of at least one metal layer. Then form a conductive metal layer over the base. Form a mask over the top surface of the conductive metal layer with C4 solder bump openings therethrough with the shape of C4 solder bump images down to the surface of the conductive metal layer above the contacts. Etch away the exposed portions of the conductive metal layer below the C4 solder bump openings to form through holes in the conductive metal layer exposing C4 solder bump plating sites on the top surface of the base below the C4 solder bump openings with the conductive metal layer remaining intact on the periphery of the through holes at the C4 solder bump plating sites. As an option, form a barrier layer over the plating sites next.
    Type: Application
    Filed: February 19, 2002
    Publication date: August 21, 2003
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Lisa A. Fanti, Randolph F. Knarr, Erik J. Roggeman, Kamalesh K. Srivastava
  • Patent number: 6531069
    Abstract: RIE processing chambers includes arrangements of gas outlets which force gas-flow-shadow elimination. Means are provided to control and adjust the direction of gases to the outlet to modify and control the direction of plasma flow at the wafer surface during processing. Means are provided to either move the exhaust paths for exhaust gases or to open and close exhaust paths sequentially, in a controlled manner, to modify flow directions of ions in the etching plasma. A combination of rotation/oscillation of a magnetic field imposed on the RIE chamber can be employed by rotation of permanent magnetic dipoles about the periphery of the RIE chamber or by controlling current through a coil wrapped around the periphery of the RIE process chamber to enhance the removal of the residues attributable to gas-flow-shadows formed by linear ion paths in the plasma.
    Type: Grant
    Filed: June 22, 2000
    Date of Patent: March 11, 2003
    Assignee: International Business Machines Corporation
    Inventors: Kamalesh K. Srivastava, Peter C. Wade, William H. Brearley, Jonathan H. Griffith
  • Publication number: 20020190028
    Abstract: A method of improving the uniformity of etching of a film on an article, the method including the steps of immersing the article containing the film into a tank of etchant, rotating the article while in the etchant for a desired amount of time so as to cause improved uniformity of etching of the film compared to etching without rotating the article, and removing the article from the tank of etchant. In a preferred embodiment of the invention, the article is a semiconductor wafer.
    Type: Application
    Filed: May 31, 2001
    Publication date: December 19, 2002
    Applicant: International Business Machines Corporation
    Inventors: Kamalesh K. Srivastava, Mary C. Cullinan-Scholl, Lisa A. Fanti, Jonathan H. Griffith, Randolph F. Knarr
  • Patent number: 6293457
    Abstract: Form a solder connector on a semiconductor device starting with a first step of forming at least one dielectric layer over a doped semiconductor substrate. Then form a hole through the dielectric layer down to the semiconductor substrate. Form a metal conductor in the hole. Form intermediate layers over the metal conductor and the dielectric layer. Then form a tapered opening down to the surface of the metal conductor. Form BLM layers including a titanium-tungsten (TiW) layer over the metal conductor and the dielectric layer with the remainder of the BLM layers being formed over the TiW layer. Form a mask over the top surface of the BLM layers with a patterning through hole located above the metal conductor exposing a portion of the surface of the BLM layers. Plate a C4 solder bump on the BLM layers in the patterning hole. Remove the mask. Wet etch away the BLM layers aside from the solder bump leaving a residual TiW layer over the dielectric layer.
    Type: Grant
    Filed: June 8, 2000
    Date of Patent: September 25, 2001
    Assignee: International Business Machines Corporation
    Inventors: Kamalesh K. Srivastava, Jonathan H. Griffith, Mary C. Cullinan-Scholl, William H. Brearley, Peter C. Wade
  • Patent number: 5800626
    Abstract: An efficient cleaning process of microelectronics devices requires lower levels of megasonic power, lower temperature and much lower concentrations of chemicals. The method controls the effectiveness of megasonics-assisted cleaning of microelectronics devices by securing a gas concentration level in the cleaning solution, such that at the process temperature the solution is partially saturated with the gas. The gas concentration can be controlled either at the plant-wide level or, preferably, at the point of use. In the latter case, two water supply inputs are provided, one of vacuum-degassed water and the other of gas-saturated water. Process water in the desired gas concentration is then obtained by mixing water from the two sources in an appropriate ratio, which resulting mixture is fed to the wafer cleaning vessel.
    Type: Grant
    Filed: February 18, 1997
    Date of Patent: September 1, 1998
    Assignee: International Business Machines Corporation
    Inventors: Susan Cohen, Emmanuel I. Cooper, Klaus Penner, David L. Rath, Kamalesh K. Srivastava
  • Patent number: 5251806
    Abstract: The present invention relates generally to a new interconnection and a method for making the same, and more particularly, to an elongated solder interconnection and a method for making the same. On an electronic carrier, a pad is formed on which a solder mass is deposited and capped with a metal layer, thereby forming an elongated solder interconnection. A further elongated solder interconnection can now be formed by forming a second solder mass on the first solder mass that has been capped by a metal layer. Additional elongated solder interconnection can be formed by capping the preceding solder mass and/or the last solder mass with a metal capping layer. Alternatively, the encapsulating layer can be in the form of a sidewall spacer formed on the sidewalls of the solder mass.
    Type: Grant
    Filed: April 16, 1992
    Date of Patent: October 12, 1993
    Assignee: International Business Machines Corporation
    Inventors: Birendra N. Agarwala, Aziz M. Ahsan, Arthur Bross, Mark F. Chadurjian, Nicholas G. Koopman, Li-Chung Lee, Karl J. Puttlitz, Sudipta K. Ray, James G. Ryan, Joseph G. Schaefer, Kamalesh K. Srivastava, Paul A. Totta, Erick G. Walton, Adolf E. Wirsing
  • Patent number: 5225711
    Abstract: The fluxless bonding in a reducing atmosphere of integrated circuit contacts containing copper is enhanced using a layer of 200 to 1500 Angstrom thick palladium which inhibits copper oxide formation before fusion and reduces all oxides to promote wetting during fusion.
    Type: Grant
    Filed: March 11, 1991
    Date of Patent: July 6, 1993
    Assignee: International Business Machines Corporation
    Inventors: Chin-An Chang, Nicholas G. Koopman, Judith M. Roldan, Steven Strickman, Kamalesh K. Srivastava, Helen L. Yeh
  • Patent number: 5130779
    Abstract: The present invention relates generally to a new interconnection and a method for making the same, and more particularly, to an elongated solder interconnection and a method for making the same. On an electronic carrier, a pad is formed on which a solder mass is deposited and capped with a metal layer, thereby forming an elongated solder interconnection. A further elongated solder interconnection can now be formed by forming a second solder mass on the first solder mass that has been capped by a metal layer. Additional elongated solder interconnection can be formed by capping the preceding solder mass and/or the last solder mass with a metal capping layer. Alternatively, the encapsulating layer can be in the form of a sidewall spacer formed on the sidewalls of the solder mass.
    Type: Grant
    Filed: June 19, 1990
    Date of Patent: July 14, 1992
    Assignee: International Business Machines Corporation
    Inventors: Birendra N. Agarwala, Aziz M. Ahsan, Arthur Bross, Mark F. Chadurjian, Nicholas G. Koopman, Li-Chung Lee, Karl J. Puttlitz, Sudipta K. Ray, James G. Ryan, Joseph G. Schaefer, Kamalesh K. Srivastava, Paul A. Totta, Erick G. Walton, Adolf E. Wirsing
  • Patent number: 5048744
    Abstract: The fluxless bonding in a reducing atmosphere of integrated circuit contacts containing copper is enhanced using a layer of 200 to 1500 Angstrom thick palladium which inhibits copper oxide formation before fusion and reduces all oxides to promote wetting during fusion.
    Type: Grant
    Filed: May 14, 1990
    Date of Patent: September 17, 1991
    Assignee: International Business Machines Corporation
    Inventors: Chin-An Chang, Nicholas G. Koopman, Judith M. Roldan, Steven Strickman, Kamalesh K. Srivastava, Helen L. Yeh