Patents by Inventor Alan Christensen

Alan Christensen 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: 6901003
    Abstract: A method, an apparatus, and a computer program are provided to reading indicia from an SRAM cell. A low value is generated on a write true line. A high value is generated on a continuous bit_line. The true node of the SRAM cell is evaluated through use of a floating voltage coupled to the true node of the SRAM cell. If the floating voltage stays substantially constant, the value read from the SRAM cell is a high. If the floating voltage is drained to ground, the value read from the SRAM cell is a low.
    Type: Grant
    Filed: July 10, 2003
    Date of Patent: May 31, 2005
    Assignee: International Business Machines Corporation
    Inventors: Chad Allen Adams, Anthony Gus Aipperspach, Todd Alan Christensen, Peter Thomas Freiburger
  • Publication number: 20050021233
    Abstract: A remote monitoring system notifying existence of a determined event including such as radiological, chemical and meteorological events. The system includes a monitoring device capable of determining the existence of a specified event at a minimum threshold value. A data logging buffer unit is in operative communication with the monitoring device and is capable of buffering, at a preset time interval, an inputted packet of information. A relay unit, in operative communication with the data logging buffer unit, transmits information delivered from the buffer unit and a mobile phone unit is in communication with the cell relay control unit. A PC in operative communication with the mobile phone unit is operable, upon receiving encoded data from the phone unit, to transmit the data to any plurality of additional remote and networked monitoring systems.
    Type: Application
    Filed: July 2, 2004
    Publication date: January 27, 2005
    Inventor: Alan Christensen
  • Patent number: 6774734
    Abstract: Circuitry and methods are disclosed for quantitatively characterizing the delay of Embedded Dynamic Random Access Memory (EDRAM) and Dynamic Random Access Memory (DRAM). The performance critical portion of the memory is placed in a ring oscillator designed such that the delay through the portion, from a rising input to the memory to a rising output, can be accurately determined. Recently, such memory elements have begun to be implemented on chips along with high-speed logic circuitry. However, the performance characteristics of the memory elements do not track the performance characteristics of the logic circuitry. The current invention allows the memory performance to be characterized along with, or separately from, characterization of the logic circuitry.
    Type: Grant
    Filed: November 27, 2002
    Date of Patent: August 10, 2004
    Assignee: International Business Machines Corporation
    Inventors: Todd Alan Christensen, Terrance Wayne Kueper, John Edward Sheets, II
  • Publication number: 20040100336
    Abstract: Circuitry and methods are disclosed for quantitatively characterizing the delay of Embedded Dynamic Random Access Memory (EDRAM) and Dynamic Random Access Memory (DRAM). The performance critical portion of the memory is placed in a ring oscillator designed such that the delay through the portion, from a rising input to the memory to a rising output, can be accurately determined. Recently, such memory elements have begun to be implemented on chips along with high-speed logic circuitry. However, the performance characteristics of the memory elements do not track the performance characteristics of the logic circuitry. The current invention allows the memory performance to be characterized along with, or separately from, characterization of the logic circuitry.
    Type: Application
    Filed: November 27, 2002
    Publication date: May 27, 2004
    Applicant: International Business Machines Corporation
    Inventors: Todd Alan Christensen, Terrance Wayne Kueper, John Edward Sheets
  • Patent number: 6741493
    Abstract: An improved memory device has a reduced number of wires for carrying local write signals. The improved memory device includes an array of memory cells. A plurality of local true bitlines is coupled to the array of memory cells. A plurality of continuous complement bitlines is coupled to the array of memory cells. The memory device also includes a plurality of write circuits. At least one write circuit is coupled to at least one continuous complement bitline and at least one local true bitline, receives information on a data input from the continuous complement bitline, and controls the local true bitline. At least one local write line is coupled to at least two of the write circuits for providing a write enable signal to the two write circuits.
    Type: Grant
    Filed: November 7, 2002
    Date of Patent: May 25, 2004
    Assignee: International Business Machines Corporation
    Inventors: Todd Alan Christensen, Peter Thomas Freiburger
  • Publication number: 20040090817
    Abstract: An improved memory device has a reduced number of wires for carrying local write signals. The improved memory device includes an array of memory cells. A plurality of local true bitlines is coupled to the array of memory cells. A plurality of continuous complement bitlines is coupled to the array of memory cells. The memory device also includes a plurality of write circuits. At least one write circuit is coupled to at least one continuous complement bitline and at least one local true bitline, receives information on a data input from the continuous complement bitline, and controls the local true bitline. At least one local write line is coupled to at least two of the write circuits for providing a write enable signal to the two write circuits.
    Type: Application
    Filed: November 7, 2002
    Publication date: May 13, 2004
    Applicant: International Business Machines Corporation
    Inventors: Todd Alan Christensen, Peter Thomas Freiburger
  • Publication number: 20040070433
    Abstract: A pulse generator circuit is disclosed including a delay element coupled to a logic circuit. The delay element receives a clock signal CLK and a signal X and produces a signal XN dependent upon the clock signal CLK and the signal X. The logic circuit receives the clock signal CLK and the signal XN and produces a signal ACLK such that ACLK=CLK·XN′. The signal ACLK may include a series of positive pulses. The delay element may be, for example, one of multiple delay elements coupled in series, and signal X may be an output of a preceding one of the delay elements. A semiconductor device is described including the above pulse generator circuit and a self-resetting logic circuit. The self-resetting logic circuit receives the signal ACLK and one or more input signals and performs a logic operation using the one or more input signals during the positive pulses.
    Type: Application
    Filed: October 10, 2002
    Publication date: April 15, 2004
    Applicant: International Business Machines Corporation
    Inventors: Chad Allen Adams, Todd Alan Christensen, Peter Thomas Freiburger
  • Patent number: 6670716
    Abstract: Silicon-on-insulator (SOI) semiconductor structures are provided for implementing transistor source connections for SOI transistor devices using buried dual rail distribution. A SOI semiconductor structure includes a SOI transistor having a silicide layer covering a SOI transistor source, a predefined buried conduction layer to be connected to a SOI transistor source, and an intermediate conduction layer between the SOI transistor and the predefined buried conduction layer. A first hole for a transistor source connection to a local interconnect is anisotropically etched in the SOI semiconductor structure to the silicide layer covering the SOI transistor source. A second hole aligned with the local interconnect hole is anisotropically etched through the SOI semiconductor structure to the predefined buried conduction layer. An insulator is disposed between the second hole and the intermediate conduction layer.
    Type: Grant
    Filed: August 22, 2002
    Date of Patent: December 30, 2003
    Assignee: International Business Machines Corporation
    Inventors: Todd Alan Christensen, John Edward Sheets, II, Gregory John Uhlmann
  • Patent number: 6667518
    Abstract: Methods and semiconductor structures are provided for implementing buried dual rail power distribution and integrated decoupling capacitance for silicon on insulator (SOI) devices. A bulk silicon substrate layer is provided that defines one power distribution rail. A high energy deep oxygen implant is performed to create a deep buried oxide layer and a first intermediate silicon layer. The deep buried oxide layer is disposed between the bulk silicon substrate layer and the first intermediate silicon layer. The first intermediate silicon layer defines another power distribution rail. A lower energy oxygen implant is performed to create a shallow buried oxide layer and a second intermediate silicon layer. The shallow buried oxide layer is disposed between the first intermediate silicon layer and the second intermediate silicon layer. A connection to the bulk silicon substrate layer is formed without making electrical connection to the intermediate silicon layers.
    Type: Grant
    Filed: August 9, 2002
    Date of Patent: December 23, 2003
    Assignee: International Business Machines Corporation
    Inventors: Todd Alan Christensen, John Edward Sheets, II
  • Patent number: 6657886
    Abstract: A high performance domino static random access memory (SRAM) is provided. The domino SRAM includes a plurality of local cell groups. Each of the plurality of local cell groups includes a plurality of SRAM cells and a local true bitline coupled to each of the plurality of SRAM cells of each local cell group. A continuous complement bitline is coupled to each of the plurality of local cell groups and is coupled to each of the plurality of SRAM cells of each local cell group. For a write to the SRAM cell complement node, only driving the continuous complement bitline is required. The domino SRAM reduces the number of required wires and required transistors as compared to prior art domino SRAM and thus the area needed and power consumption are reduced for the domino SRAM.
    Type: Grant
    Filed: May 7, 2002
    Date of Patent: December 2, 2003
    Assignee: International Business Machines Corporation
    Inventors: Chad Allen Adams, Anthony Gus Aipperspach, Todd Alan Christensen, Peter Thomas Freiburger
  • Publication number: 20030210565
    Abstract: A high performance domino static random access memory (SRAM) is provided. The domino SRAM includes a plurality of local cell groups. Each of the plurality of local cell groups includes a plurality of SRAM cells and a local true bitline coupled to each of the plurality of SRAM cells of each local cell group. A continuous complement bitline is coupled to each of the plurality of local cell groups and is coupled to each of the plurality of SRAM cells of each local cell group. For a write to the SRAM cell complement node, only driving the continuous complement bitline is required. The domino SRAM reduces the number of required wires and required transistors as compared to prior art domino SRAM and thus the area needed and power consumption are reduced for the domino SRAM.
    Type: Application
    Filed: May 7, 2002
    Publication date: November 13, 2003
    Applicant: International Business Machines Corporation
    Inventors: Chad Allen Adams, Anthony Gus Aipperspach, Todd Alan Christensen, Peter Thomas Freiburger
  • Patent number: 6645796
    Abstract: A method and semiconductor structure including silicon-on-insulator (SOI) devices are provided for implementing reach through buried interconnect. A semiconductor stack includes a predefined buried conductor to be connected through multiple insulator layers and at least one intermediate conductor above the predefined buried conductor. A hole is anisotropically etched through the semiconductor stack to the predefined buried conductor. The etched hole extends through the at least one intermediate conductor and the insulators to the predefined buried conductor in the semiconductor stack. A thin layer of insulator is deposited over an interior of the etched hole. The deposited thin insulator layer is anisotropically etched to remove the deposited thin insulator layer from a bottom of the hole exposing the predefined buried conductor in the semiconductor stack with the thin insulator layer covering sidewalls of the hole to define an insulated opening.
    Type: Grant
    Filed: November 21, 2001
    Date of Patent: November 11, 2003
    Assignee: International Business Machines Corporation
    Inventors: Todd Alan Christensen, John Edward Sheets, II
  • Publication number: 20030205759
    Abstract: A method and apparatus for reducing parasitic bipolar transistor leakage current in a Silicon on Insulator (SOI) Metal Oxide Semiconductor (MOS). A capacitor is operatively coupled between the base and emitter terminals of the parasitic bipolar transistor. The capacitor effectively reduces the base to emitter voltage of the parasitic transistor thereby reducing leakage current generated at the collector terminal.
    Type: Application
    Filed: October 23, 2001
    Publication date: November 6, 2003
    Applicant: International Business Machines Corporation
    Inventors: Todd Alan Christensen, David Michael Friend, Nghia Van Phan, John Edward Sheets
  • Patent number: 6643804
    Abstract: An apparatus, program product, and method of testing a silicon-on-insulator (SOI) static random access memory (SRAM) introduce switching history effects to a memory cell during testing to stress the memory cell such that a reliable determination of stability may be made. Stress is applied to a memory cell through the use of a bitline precharge stress operation, which utilizes the bitline pairs coupled to a memory cell to attempt to flood the memory cell with charge and thereby attempt to cause the memory cell to unexpectedly switch state. The bitline precharge stress operation is performed immediately after the memory cell has been switched to one state after being maintained in an opposite state for a length of time that is sufficient to introduce switching history effects to the memory cell.
    Type: Grant
    Filed: April 19, 2000
    Date of Patent: November 4, 2003
    Assignee: International Business Machines Corporation
    Inventors: Anthony Gus Aipperspach, Todd Alan Christensen, Douglas Michael Dewanz
  • Publication number: 20030170936
    Abstract: Methods and silicon-on-insulator (SOI) semiconductor structures are provided for implementing transistor source connections for SOI transistor devices using buried dual rail distribution. A SOI semiconductor structure includes a SOI transistor having a silicide layer covering a SOI transistor source, a predefined buried conduction layer to be connected to a SOI transistor source, and an intermediate conduction layer between the SOI transistor and the predefined buried conduction layer. A first hole for a transistor source connection to a local interconnect is anisotropically etched in the SOI semiconductor structure to the silicide layer covering the SOI transistor source. A second hole aligned with the local interconnect hole is anisotropically etched through the SOI semiconductor structure to the predefined buried conduction layer. An insulator is disposed between the second hole and the intermediate conduction layer.
    Type: Application
    Filed: August 22, 2002
    Publication date: September 11, 2003
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Todd Alan Christensen, John Edward Sheets, Gregory John Uhlmann
  • Publication number: 20030123279
    Abstract: An SRAM memory cell made with increased stability using SOI technology is provided. Increased stability results from a decreased threshold voltage of the pullup pfets included in the inverter. Preferably the decrease of threshold voltage is achieved using a decreased concentration of phosphorus, antimony, arsenic, or other n-type ions during implantation.
    Type: Application
    Filed: January 3, 2002
    Publication date: July 3, 2003
    Applicant: International Business Machines Corporation
    Inventors: Anthony Gus Aipperspach, Todd Alan Christensen
  • Patent number: 6570433
    Abstract: A method and apparatus are provided for laser fuseblow protection in transistors, such as silicon-on-insulator (SOI) transistors. The transistors are connected to a fuse. A pair of diodes are connected in series between a high supply and ground. A common connection of the series connected pair of diodes is connected to a common connection of the fuse and transistors. A charge is shunted to the high supply or ground by the pair of diodes with a first voltage a set value above the high supply and a second voltage a set value below the ground. A pair of protection diodes are provided on each side of the fuse with transistors. The transistors are either connected to one side of the fuse or to both sides of the fuse.
    Type: Grant
    Filed: August 9, 2001
    Date of Patent: May 27, 2003
    Assignee: International Business Machines Corporation
    Inventors: Anthony Gus Aipperspach, Todd Alan Christensen
  • Publication number: 20030094654
    Abstract: Methods and semiconductor structures are provided for implementing buried dual rail power distribution and integrated decoupling capacitance for silicon on insulator (SOI) devices. A bulk silicon substrate layer is provided that defines one power distribution rail. A high energy deep oxygen implant is performed to create a deep buried oxide layer and a first intermediate silicon layer. The deep buried oxide layer is disposed between the bulk silicon substrate layer and the first intermediate silicon layer. The first intermediate silicon layer defines another power distribution rail. A lower energy oxygen implant is performed to create a shallow buried oxide layer and a second intermediate silicon layer The shallow buried oxide layer is disposed between the first intermediate silicon layer and the second intermediate silicon layer. A connection to the bulk silicon substrate layer is formed without making electrical connection to the intermediate silicon layers.
    Type: Application
    Filed: August 9, 2002
    Publication date: May 22, 2003
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Todd Alan Christensen, John Edward Sheets
  • Publication number: 20030094653
    Abstract: A method and semiconductor structure including silicon-on-insulator (SOI) devices are provided for implementing reach through buried interconnect. A semiconductor stack includes a predefined buried conductor to be connected through multiple insulator layers and at least one intermediate conductor above the predefined buried conductor. A hole is anisotropically etched through the semiconductor stack to the predefined buried conductor. The etched hole extends through the at least one intermediate conductor and the insulators to the predefined buried conductor in the semiconductor stack. A thin layer of insulator is deposited over an interior of the etched hole. The deposited thin insulator layer is anisotropically etched to remove the deposited thin insulator layer from a bottom of the hole exposing the predefined buried conductor in the semiconductor stack with the thin insulator layer covering sidewalls of the hole to define an insulated opening.
    Type: Application
    Filed: November 21, 2001
    Publication date: May 22, 2003
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Todd Alan Christensen, John Edward Sheet
  • Publication number: 20030071692
    Abstract: Measurement methods and a ring oscillator circuit are provided for evaluating dynamic circuits. The ring oscillator circuit includes a one-shot pulse generator receiving a single transition input signal and producing a pulse output signal having a rising transition and falling transition. The dynamic circuit to be evaluated is coupled to an output of the one-shot pulse generator receiving the pulse output signal of the one-shot pulse generator and producing a delayed output pulse at an output. A divide-by-two circuit is coupled to the output of the dynamic circuit to be evaluated. An output signal of the divide-by-two circuit is fed back to the one-shot pulse generator, and the cycle is repeated, thus oscillating. A multiplexer is connected between output of the dynamic circuit to be evaluated and the divide-by-two circuit.
    Type: Application
    Filed: October 15, 2001
    Publication date: April 17, 2003
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Anthony Gus Aipperspach, Todd Alan Christensen, Peter Thomas Freiburger, David Michael Friend, Nghia Van Phan