Patents Represented by Attorney Robert A. Walsh
  • Patent number: 6658604
    Abstract: To overcome these problems, the present invention generates two window strobes and uses the two window strobes to determine if skew between two signals meets predetermined criteria. One of the window strobes is used to test one of the signals, and the other window strobe is generated relative to the first window strobe. The second window strobe tests the other signal (or signals, if they are data signals). From the tests of the two window strobes, it can be determined if the skew between the first and second signals meets predetermined criteria. In particular, the two window strobes are placed relative to each other and to the signals being tested in such a way that when both window strobes indicate passing conditions, skew between the two signals is guaranteed.
    Type: Grant
    Filed: October 10, 2000
    Date of Patent: December 2, 2003
    Assignee: International Business Machines Corporation
    Inventors: William R. Corbin, David P. Monty, Erik A. Nelson, Alan D. Norris, Steven W. Tomashot, David E. Chapman, Timothy E. Fiscus
  • Patent number: 6647579
    Abstract: A semiconductor wafer chemical mechanical treatment apparatus having a sectional extended arm carrying a head. The sectional arm is comprised of a fixed yoke and an elongated arm positioned in said yoke on a pivot. The elongated arm carries a first means thereon for establishing and maintaining a given loading or pressure on the head. A second means, is positioned on the yoke, adjacent to the elongated arm for temporarily altering the given loading or pressure on the head established by the first means without disturbing the setting of the first means such that when the second means is reset the given head load or pressure established by said first means is automatically restored.
    Type: Grant
    Filed: December 18, 2000
    Date of Patent: November 18, 2003
    Assignee: International Business Machines Corp.
    Inventors: Paul A. Manfredi, Douglas P. Nadeau
  • Patent number: 6650580
    Abstract: A method for testing semiconductor memory device using an active restore weak write test mode for resistive bitline contacts. During the write margin testing a test signal is used to block the bitline restore devices from turning off during the memory write cycle.
    Type: Grant
    Filed: July 26, 2002
    Date of Patent: November 18, 2003
    Assignee: International Business Machines Corporation
    Inventor: George M. Braceras
  • Patent number: 6643807
    Abstract: A structure and method for an integrated circuit which includes read/write memory having a plurality of memory devices, each of the memory devices having a unique address; a built-in self-test (BIST) engine, the BIST engine having a controller responsive to a test enable signal and operative to generate and store test data in the read/write memory; a comparator operative to compare retrieved data read from the read/write memory and the test data during a first pass test, the comparator identifying failed cycles where the retrieved data does not correspond correctly to the test data; and a diagnostic unit operative to store the failed cycles and being responsive to the controller generating and storing the test data in the read/write memory and operative to store failed data and failing addresses during a first pass test, wherein the BIST engine stops only at each of the failed cycles during the first pass test.
    Type: Grant
    Filed: August 1, 2000
    Date of Patent: November 4, 2003
    Assignee: International Business Machines Corporation
    Inventors: Jay G. Heaslip, Gary W. Maier, Gerard M. Salem, Timothy J. Von Reyn
  • Patent number: 6636995
    Abstract: A method of testing a digital logic circuit comprises first providing a logic circuit having a plurality of interconnected circuits each having an input and an output; determining a gate level representation of the logic circuit including test nets for determining faults in the circuit; and identifying a portion of the nets which are most difficult to test, including nets which are most difficult to control and nets which are most difficult to observe. The method then includes inserting into the logic circuit control latches for nets which are determined to be most difficult to control and inserting into the logic circuit observation latches for nets which are determined to be most difficult to observe. Using the inserted control latches and observation latches, the method further includes testing the nets which are determined to be most difficult to control and nets which are hardest to observe and determining faults in the circuit.
    Type: Grant
    Filed: July 13, 2000
    Date of Patent: October 21, 2003
    Assignee: International Business Machines Corporation
    Inventors: Alvar A. Dean, Joseph A. Iadanza, David E. Lackey, Sebastian T. Ventrone
  • Patent number: 6627926
    Abstract: In a semiconductor device using fill shape patterns incorporated into wiring levels to increase the planarity of the wiring levels, the fill shapes are aligned from one wiring level to another wiring level to provide lines of sight to lower wiring levels for visual inspection. Also, in accordance with the invention, selected aligned fill shapes are interconnected with vias to form conductive stacks for contacting lower wiring level conductive wires from upper wiring levels in order to perform electrical test probing/diagnostics.
    Type: Grant
    Filed: February 16, 2001
    Date of Patent: September 30, 2003
    Assignee: International Business Machines Corporation
    Inventors: Thomas J. Hartswick, Mark E. Masters
  • Patent number: 6618281
    Abstract: A content addressable memory (CAM) and method capable of ignoring and correcting bit errors contained therein is disclosed. In an exemplary embodiment, the CAM includes a plurality of individual CAM cells for storing a codeword having a number of bits associated therewith. A match line is coupled to each of the plurality of individual CAM cells, and is used to indicate a match status of a comparand word that is compared to the stored codeword. The match status is reflective of either a match state or a mismatch state. A sensing apparatus is used for latching the match line to the match state whenever the comparand word mismatches the stored codeword by a number of N or fewer bits, wherein N is defined a maximum number of correctable bits for a given ECC algorithm used.
    Type: Grant
    Filed: May 15, 2002
    Date of Patent: September 9, 2003
    Assignee: International Business Machines Corporation
    Inventor: Tarl S. Gordon
  • Patent number: 6618279
    Abstract: A method for determining a desired operating impedance for a computer memory circuit includes applying, to a reference circuit, a test impedance value to a reference circuit. The test impedance value is controlled by a binary count. A determination is made, based upon the applied test impedance value, whether the reference circuit is in either a first state or a second state. The binary count is incremented if the reference circuit is in the first state and decremented if the reference circuit is in the second state. A condition is determined in which the reference circuit oscillates between the first state and said second state, and a pair of binary count values is stored. The desired operating impedance for the computer memory circuit corresponds to the lower of the stored pair of binary count values.
    Type: Grant
    Filed: August 6, 2001
    Date of Patent: September 9, 2003
    Assignee: International Business Machines Corporation
    Inventors: Fred J. Towler, Reid A. Wistort, Jason Rotella
  • Patent number: 6618682
    Abstract: A method and system are provided that minimize wafer or package level test time without adversely impacting yields in downstream manufacturing processes or degrading outgoing quality levels. The method provides optimization by determining, a priority, the most effective set of tests for a given lot or wafer. The invention implements a method using a processor-based system involving the integration of multiple sources of data that include: historical and realtime, product specific and lot specific, from wafer fabrication data (i.e., process measurements, defect inspections, and parametric testing), product qualification test results, physical failure analysis results and manufacturing functional test results. These various forms of data are used to determine an optimal set of tests to run using a test application sequence, on a given product to optimize test time with minimum risk to yield or product quality.
    Type: Grant
    Filed: April 20, 2001
    Date of Patent: September 9, 2003
    Assignee: International Business Machines Corporation
    Inventors: Raymond J. Bulaga, Anne E. Gattiker, John L. Harris, Phillip J. Nigh, Leo A. Noel, William J. Thibault, Jody J. Van Horn, Donald L. Wheater
  • Patent number: 6603195
    Abstract: A semiconductor module includes a semiconductor chip, a lead frame having lead fingers, and a down set member within an encapsulant for reduce warpage and providing a more planar package by balancing thermal stress between the lead fingers and the encapsulant. The down set member can be a bent portion of the lead frame. It can also be a separate body, such as a dummy semiconductor chip.
    Type: Grant
    Filed: June 28, 2000
    Date of Patent: August 5, 2003
    Assignee: International Business Machines Corporation
    Inventors: David V. Caletka, James L. Carper, John P. Cincotta, Kibby B. Horsford, Gary H. Irish, John J. Lajza, Jr., Gordon C. Osborne, Jr., Charles R. Ramsey, Robert M. Smith, Michael J. Vadnais
  • Patent number: 6599173
    Abstract: A CMP slurry for and method of polishing a semiconductor wafer during formation of metal interconnects are disclosed. The present invention utilizes a first slurry comprising a first oxidizer, preferably ferric nitrate, to remove the excess metal of the metal interconnect but which leaves the metal residues on the surface of the wafer. A second slurry comprising another oxidizer, preferably potassium iodate solution, having a greater affinity to both the metal residue and the liner material than the underlying dielectric is used to remove the metal residue and liner material with significantly reduced scratching of the underlying dielectric. The more robust metal interconnects formed utilizing the present invention is effective in lowering the overall resistance of a wafer, reducing the number of shorts, and provides greater protection of the underlying dielectric. Overpolishing of the wafer and its associated problems are avoided.
    Type: Grant
    Filed: June 30, 2000
    Date of Patent: July 29, 2003
    Assignee: International Business Machines Corporation
    Inventors: Jose L. Cruz, Cuc K. Huynh, Timothy C. Krywanczyk, Douglas K. Sturtevant
  • Patent number: 6597596
    Abstract: A growable CAM array and an ASIC-compatible CAM architecture based on modular cascadable CAM blocks, each CAM block containing a sub-entry including a segment of the match line of a CAM entry, each block's output being its match-line segment's voltage gated by a combinatorial logic gate. Each sub-entry's structure is that of a short CAM entry with a short Match Line (a match line segment) with a small capacitance. Each CAM block outputs a signal that can enable or inhibit a CAM search in the sub-entry in the next CAM block. A variety of exemplary circuits for gating match line segments within CAM blocks, and methods of selecting and combining the resulting variety of CAM blocks to obtain power-savings and/or high performance. An ASIC library including library elements having electrical rules that describe devices within and describe interconnections between the devices within a CAM block.
    Type: Grant
    Filed: November 1, 2002
    Date of Patent: July 22, 2003
    Assignee: International Business Machines Corporation
    Inventors: Tarl S. Gordon, Rahul K. Nadkarni
  • Patent number: 6591388
    Abstract: Test data is provided through shift registers, operated at a high clock rate comparable to or exceeding a normal high speed clock rate of a chip being tested, to each of a plurality of scan chains configured from registers present on the chip; respective latches of which are connected to inputs and outputs of logic array partitions to be tested. Reduced test clock rate of input and output circuits of the scan chains is accommodated by high speed source and sink shift registers. The source and sink registers are fully loaded and unloaded between consecutive test clock signals and test signals are preferably applied to and collected from the chip in a single serial string through a single pair of tester input/output pins.
    Type: Grant
    Filed: April 18, 2000
    Date of Patent: July 8, 2003
    Assignee: International Business Machines Corporation
    Inventor: Timothy J. Vonreyn
  • Patent number: 6590382
    Abstract: A test apparatus and a method for testing an integrated circuit's data storage device's input/output signal pins for alternating current (AC) defects, by providing an interface that will couple each respective individual test contact, in a subset of said contacts, to a select plurality of the data storage input/output signal pins so that when a selected data string is introduced into the integrated circuit so that each input/output pin on a data storage device in the integrated circuit will be tested in sequence whereby the number of contacts required by the tester can be reduced.
    Type: Grant
    Filed: December 22, 2000
    Date of Patent: July 8, 2003
    Assignee: International Business Machines Corp.
    Inventors: Frank W. Angelotti, Louis B. Bushard, Matthew S. Grady, Scott A. Strissel
  • Patent number: 6590404
    Abstract: An assembly, including a tool for measuring an applied force and its centroid relative to the center of the tool. A method of measuring and adjusting a force and its centroid applied to a semiconductor chip in a socket by an abutting heat sink consisting of the steps of inserting the tool in the socket, applying a heat sink on the tool, measuring the applied force and its centroid with respect to the center of the tool, adjusting the heat sink until the centroid of the applied force is substantially aligned with the center of the tool, removing the heat sink and tool, from the socket, substituting a semiconductor chip for the tool and reapplying the heat sink whereby the centroid of the force applied by the heat sink is substantially aligned with the center surface of the semiconductor chip in the semiconductor device.
    Type: Grant
    Filed: July 5, 2001
    Date of Patent: July 8, 2003
    Assignee: International Business Machines Corp.
    Inventors: David L. Gardell, Edward J. Sukuskas
  • Patent number: 6587388
    Abstract: A method for preparing a dynamic random access memory (DRAM) cell for a write operation with a preset condition is disclosed. In an exemplary embodiment, the method includes creating a preset voltage level within the cell prior to a delayed write back in a destructive read architecture, which preset voltage level has a value between a logic 0 voltage level and a logic 1 voltage level. The logic 0 voltage level corresponds to a first cell voltage value when the cell has a 0 bit stored therein, and the logic 1 voltage level corresponds to a second cell voltage value when the cell has a 1 bit stored therein. Prior to the creation of the preset voltage level within the cell, the cell has an initial voltage value corresponding to either the logic 0 voltage level or the logic 1 voltage level.
    Type: Grant
    Filed: April 27, 2001
    Date of Patent: July 1, 2003
    Assignee: International Business Machines Corporation
    Inventors: Toshiaki Kirihata, Sang Hoo Dhong, Hwa-Joon Oh
  • Patent number: 6579149
    Abstract: A device and method for providing precision alignment and support for an optical film measurement probe in the wafer rinse tank of a CMP polish tool. The device includes of a probe carrier, and spring loaded support guides attached to a support ring that supports and locates the mechanism in the rinse tank of the CMP tool. The probe carrier has multiple beveled bearing pads (three or more) that contact the rim of the rotating wafer chuck. Pressure from the chuck against these pads forces the probe carrier to maintain a fixed distance and orientation relative to the wafer while allowing the smooth rotation and motion of the wafer and chuck. Further, an integrated the wafer spray nozzles can be attached to the probe carrier that is located so as to minimize interference between wafer spraying and the probe carrier.
    Type: Grant
    Filed: February 6, 2001
    Date of Patent: June 17, 2003
    Assignee: International Business Machines Corporation
    Inventors: Richard J. Lebel, Frederic Maurer, Rock Nadeau, Paul H. Smith, Jr., Hemantha K. Wickramasinghe, Theodore G. van Kessel
  • Patent number: 6577548
    Abstract: A method and circuit for a self timed DRAM. The circuit includes interlock circuits coupled to an extension of the DRAM. The extension does not store “real” data but mimics the operations of the DRAM. The interlock circuits, in conjunction with the extension monitor and control read and write timings of the DRAM and self adjust these timings via feedback. To properly track DRAM cell timings, the interlock circuits and extension use the same cell design and load conditions as the DRAM. The method includes: activating a wordline and reference wordline, interlocking the sense amplifiers, column select and write back functions of the primary DRAM array by monitoring the identical reference cells and the state of the bitline in the extension DRAM array.
    Type: Grant
    Filed: September 26, 2002
    Date of Patent: June 10, 2003
    Assignee: International Business Machines Corporation
    Inventors: John E. Barth, Jr., Jeffrey H. Dreibelbis, Erik A. Nelson
  • Patent number: 6577154
    Abstract: A compensated driver for maintaining constant impedance during data transfer from an integrated circuit comprises an output portion having an output device to transfer data from the integrated circuit and a mimic circuit portion having a sample output device scaled to a fraction of the output device adapted to accept a reference current and generate a sample voltage. A mimic circuit portion has a sample output device scaled to a fraction of the output device adapted to accept a reference current and generate a sample voltage. A differential amplifier portion is adapted to generate a control voltage in response to a reference voltage and the sample voltage. A predrive portion applies either a ground or the predetermined control voltage from the differential amplifier portion to the output stage portion in response to an input, the control voltage regulating the output device in the output stage portion to achieve a more constant impedance.
    Type: Grant
    Filed: May 3, 2001
    Date of Patent: June 10, 2003
    Assignee: International Business Machines Corporation
    Inventors: John A. Fifield, Russell J. Houghton
  • Patent number: 6576909
    Abstract: An ion generator chamber, for an implantation apparatus, having its interior walls surfaces knurled or roughened so that any of the materials used in the chamber cannot deposit onto the interior wall surfaces in a size sufficiently large enough to adversely affect the operation of the chamber, if the deposits peel off the interior walls of the chamber. By limiting the size of any deposits on interior chamber walls, the invention extends the average life of the filaments used in the chamber as well as extending the average time between any necessary cleaning of the inner chamber walls thereby extending the operating life of the chamber.
    Type: Grant
    Filed: February 28, 2001
    Date of Patent: June 10, 2003
    Assignee: International Business Machines Corp.
    Inventors: Gary A. Donaldson, Donald W. D. Rakowski, Nick G. Selva