Patents by Inventor Stephen L. Casper

Stephen L. Casper 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: 6757202
    Abstract: Voltage coupling/decoupling devices are provided within DRAM devices for improving the bias sensing of sense amplifiers and thus the refresh performance. The voltage coupling/decoupling devices couple or decouple bias voltage from corresponding digit lines coupled to the sense amplifiers. By coupling and decoupling voltage from the digit lines, the time interval between refresh operations can be increased.
    Type: Grant
    Filed: August 29, 2002
    Date of Patent: June 29, 2004
    Assignee: Micron Technology, Inc.
    Inventors: David J. McElroy, Stephen L. Casper
  • Patent number: 6714468
    Abstract: A voltage generator coupled to a capacitor is provided. In one embodiment, the voltage generator includes an input that receives a control signal that indicates a desired current level output, and further includes circuitry adapted to generate a selected voltage, activate a first current path for an output of the voltage generator when a first current level is desired, and activate a second current path for the output of the voltage generator when a second current level is desired.
    Type: Grant
    Filed: March 13, 2002
    Date of Patent: March 30, 2004
    Assignee: Micron Technology, Inc.
    Inventor: Stephen L. Casper
  • Publication number: 20040042276
    Abstract: Voltage coupling/decoupling devices are provided within DRAM devices for improving the bias sensing of sense amplifiers and thus the refresh performance. The voltage coupling/decoupling devices couple or decouple bias voltage from corresponding digit lines coupled to the sense amplifiers. By coupling and decoupling voltage from the digit lines, the time interval between refresh operations can be increased.
    Type: Application
    Filed: August 29, 2002
    Publication date: March 4, 2004
    Applicant: MICRON TECHNOLOGY, INC.
    Inventors: David J. McElroy, Stephen L. Casper
  • Patent number: 6686796
    Abstract: An integrated circuit voltage regulator compensates for temperature variations by adjusting a gain of an amplifier. In one embodiment, the gain is controlled by a voltage divider circuit comprised of a first resistor having a first temperature coefficient, and a second resistor having a second temperature coefficient which is different from the first coefficient. In one embodiment, the first resistor is a p-channel transistor and the second resistance is fabricated from integrated circuit active area.
    Type: Grant
    Filed: January 24, 2003
    Date of Patent: February 3, 2004
    Assignee: Micron Technology, Inc.
    Inventor: Stephen L. Casper
  • Patent number: 6633506
    Abstract: An antifuse detection circuit is described which uses a latching circuit and two antifuses. The antifuses are coupled between the latch circuit and ground. The latching circuit described is a differential circuit which can detect which one of the two antifuses has been programmed. The circuit accurately detects an antifuse which has a relatively high resistance after being programmed.
    Type: Grant
    Filed: January 29, 2001
    Date of Patent: October 14, 2003
    Assignee: Micron Technology, Inc.
    Inventors: Stephen L. Casper, Chris G. Martin
  • Patent number: 6625080
    Abstract: An antifuse detection circuit is described which uses a latching circuit and two antifuses. The antifuses are coupled between the latch circuit and ground. The latching circuit described is a differential circuit which can detect which one of the two antifuses has been programmed. The circuit accurately detects an antifuse which has a relatively high resistance after being programmed.
    Type: Grant
    Filed: January 9, 2002
    Date of Patent: September 23, 2003
    Assignee: Micron Technology, Inc.
    Inventors: Stephen L. Casper, Chris G. Martin
  • Publication number: 20030174559
    Abstract: A method for storing a temperature threshold in an integrated circuit includes measuring operating parameters of the integrated circuit versus temperature, calculating a maximum temperature at which the integrated circuit performance exceeds predetermined specifications and storing parameters corresponding to the maximum temperature in a comparison circuit in the integrated circuit by selectively blowing fusable devices in the comparison circuit. The fusable devices may be antifuses.
    Type: Application
    Filed: February 24, 2003
    Publication date: September 18, 2003
    Inventors: Christopher B. Cooper, Ming-Bo Liu, Chris G. Martin, Troy A. Manning, Stephen L. Casper, Charles H. Dennison, Brian M. Shirley, Brian L. Brown, Shubneesh Batra
  • Publication number: 20030156463
    Abstract: A sense circuit for reading a resistance level of a programmable conductor random access memory (PCRAM) cell is provided. A voltage potential difference is introduced across a PCRAM cell by activating an access transistor from a raised rowline voltage. Both a digit line and a digit complement reference line are precharged to a first predetermined voltage. The cell being sensed has the precharged voltage discharged through the resistance of the programmable conductor memory element of the PCRAM cell. A comparison is made of the voltage read at the digit line and at the reference conductor. If the voltage at the digit line is greater than the reference voltage, the cell is read as a high resistance value (e.g., logic HIGH); however, if the voltage measured at the digit line is lower than that of the reference voltage, the cell is read as a low resistance value (e.g., logic LOW).
    Type: Application
    Filed: February 19, 2002
    Publication date: August 21, 2003
    Inventors: Stephen L. Casper, Kevin Duesman, Glen Hush
  • Patent number: 6587892
    Abstract: A memory device is described which is fabricated as an integrated circuit and uses distributed bond pads for electrical connection to an external conductive lead. The distributed bond pads are attached to a external lead, thereby eliminating bus lines on the integrated circuit memory. Distributed buffer circuits are described which can be included with the distributed bond pads to increase data communication time between the memory device and an external processor.
    Type: Grant
    Filed: January 22, 2001
    Date of Patent: July 1, 2003
    Assignee: Micron Technology, Inc.
    Inventor: Stephen L. Casper
  • Patent number: 6587978
    Abstract: The invention is a dynamic random access memory (DRAM) device having an electronic test key fabricated on board and is a method for testing the DRAM. The electronic test key generates a signal which effects a variation in a pulse width of an internal control signal to stress the DRAM during a test mode.
    Type: Grant
    Filed: February 20, 1996
    Date of Patent: July 1, 2003
    Assignee: Micron Technology, Inc.
    Inventors: Todd A. Merritt, George B. Raad, Stephen L. Casper
  • Patent number: 6586290
    Abstract: An ESD protection structure for I/O pads is formed with well resistors underlying the active areas of a transistor. The well resistors are coupled in series with the active areas and provide additional resistance which is effective in protecting the transistor from ESD events. Metal conductors over the active areas, have a plurality of contacts to the active areas formed through an insulative layer to contact the active areas. Additional active areas adjacent to the active areas of the transistor are also coupled to the well resistors, and to a conductive layer which provides a conductor to the I/O pads. The active areas are silicided to reduce their resistance and increase the switching speed of the transistor. The n-well resistors are coupled in series to provide a large resistance with respect to that of the active areas to reduce the impact of ESD events.
    Type: Grant
    Filed: June 15, 1998
    Date of Patent: July 1, 2003
    Assignee: Micron Technology, Inc.
    Inventors: Stephen L. Casper, Manny K. F. Ma, Joseph C. Sher
  • Publication number: 20030107430
    Abstract: An integrated circuit voltage regulator compensates for temperature variations by adjusting a gain of an amplifier. In one embodiment, the gain is controlled by a voltage divider circuit comprised of a first resistor having a first temperature coefficient, and a second resistor having a second temperature coefficient which is different from the first coefficient. In one embodiment, the first resistor is a p-channel transistor and the second resistance is fabricated from integrated circuit active area.
    Type: Application
    Filed: January 24, 2003
    Publication date: June 12, 2003
    Applicant: Micron Technology, Inc.
    Inventor: Stephen L. Casper
  • Patent number: 6569727
    Abstract: A 16 megabit (224) or greater density single deposition layer metal Dynamic Random Access Memory (DRAM) part is described which allows for a die that fits within an industry-standard 300 ml wide SOJ (Small Outline J-wing) package or a TSOP (Thin, Small Outline Package) with little or no speed loss over previous double metal deposition layered 16 megabit DRAM designs. This is accomplished using a die architecture which allows for a single metal layer signal path, together with the novel use of a lead frame to remove a substantial portion of the power busing from the die, allowing for a smaller, speed-optimized DRAM. The use of a single deposition layer metal results in lower production costs, and shorter production time.
    Type: Grant
    Filed: May 8, 1997
    Date of Patent: May 27, 2003
    Assignee: Micron Technology, Inc.
    Inventors: Stephen L. Casper, Timothy J. Allen, D. Mark Durcan, Brian M. Shirley, Howard E. Rhodes
  • Patent number: 6552945
    Abstract: A method for storing a temperature threshold in an integrated circuit includes measuring operating parameters of the integrated circuit versus temperature, calculating a maximum temperature at which the integrated circuit performance exceeds predetermined specifications and storing parameters corresponding to the maximum temperature in a comparison circuit in the integrated circuit by selectively blowing fusable devices in the comparison circuit. The fusable devices may be antifuses. As a result, the integrated circuit is able to provide signals to devices external to the integrated circuit to indicate that the integrated circuit may be too hot to operate properly.
    Type: Grant
    Filed: January 23, 2001
    Date of Patent: April 22, 2003
    Assignee: Micron Technology, Inc.
    Inventors: Christopher B. Cooper, Ming-Bo Liu, Chris G. Martin, Troy A. Manning, Stephen L. Casper, Charles H. Dennison, Brian M. Shirley, Brian L. Brown, Shubneesh Batra
  • Patent number: 6515885
    Abstract: An address buffer for a memory device comprises a tri-state input stage, an address output latch, and an inverter that are successively coupled. In one embodiment, the address buffer uses address enable signals for controlling both the tri-state input stage and the address output latch. In another embodiment, the tri-state input stage includes series coupled pairs of N and P channel transistors. The address signal is provided to gates of one P channel and one N channel transistor which form an inverter. The other two transistors have their gates coupled to the address enable signal and its complement for enabling the tri-state input stage. In another embodiment, the address output latch includes a multiplexed feedback loop that is controlled by the address enable signal and its complement. A method of operating the buffer comprises sampling a signal. The sampled signal is inverted. The inverted sampled signal is latched. Finally, the latched signal is inverted.
    Type: Grant
    Filed: October 11, 2000
    Date of Patent: February 4, 2003
    Assignee: Micron Technology, Inc.
    Inventor: Stephen L. Casper
  • Patent number: 6512412
    Abstract: An integrated circuit voltage regulator compensates for temperature variations by adjusting a gain of an amplifier. In one embodiment, the gain is controlled by a voltage divider circuit comprised of a first resistor having a first temperature coefficient, and a second resistor having a second temperature coefficient which is different from the first coefficient. In one embodiment, the first resistor is a p-channel transistor and the second resistance is fabricated from integrated circuit active area.
    Type: Grant
    Filed: February 16, 1999
    Date of Patent: January 28, 2003
    Assignee: Micron Technology, Inc.
    Inventor: Stephen L. Casper
  • Patent number: 6507074
    Abstract: An ESD protection structure for I/O pads is formed with well resistors underlying the active areas of a transistor The well resistors are coupled in series with the active areas and provide additional resistance which is effective in protecting the transistor from ESD events. Metal conductors over the active areas, have a plurality of contacts to the active areas formed through an insulative layer to contact the active areas. Additional active areas adjacent to the active areas of the transistor are also coupled to the well resistors, and to a conductive layer which provides a conductor to the I/O pads. The active areas are silicided to reduce their resistance and increase the switching speed of the transistor. The n-well resistors are coupled in series to provide a large resistance with respect to that of the active areas to reduce the impact of ESD events.
    Type: Grant
    Filed: August 30, 2001
    Date of Patent: January 14, 2003
    Assignee: Micron Technology, Inc.
    Inventors: Stephen L. Casper, Manny K. F. Ma, Joseph C. Sher
  • Publication number: 20020194450
    Abstract: A method and apparatus of reducing the time for enabling a dynamic random access memory (DRAM) upon initial application of power, comprises generating an internal RAS signal upon initial power up to generate internal voltages. The internal RAS pulse is asserted after a short time delay ends. After the internal RAS pulse is asserted, voltages on a digit line pair are amplified with a sense amplifier. Then, the amplified voltages on the digit line pair are equilibrated with an equilibration circuit. The equilibrated voltage is also coupled through the equilibration circuit to charge a common plate of a memory cell capacitor.
    Type: Application
    Filed: August 20, 2002
    Publication date: December 19, 2002
    Applicant: Micron Technology, Inc.
    Inventor: Stephen L. Casper
  • Patent number: 6475851
    Abstract: Adjacent unassociated field-effect transistors are formed from a single continuous layer of uniformly doped material in a semiconductor substrate. An insulating layer is formed over the active layer. A number of gates in a conductive layer define the transistors. Forming a connection between one of the gates and a reference potential forms a boundary between the unassociated transistors across the active material by preventing carrier transport thereacross.
    Type: Grant
    Filed: July 29, 1998
    Date of Patent: November 5, 2002
    Assignee: Micron Technology. Inc.
    Inventors: Stephen L. Casper, Brian M. Shirley, Kevin G. Duesman
  • Patent number: 6445610
    Abstract: A variable voltage is provided to gates of isolation transistors in DRAM devices between digit lines containing many storage cells and a sense amplifier. The gate of the isolation transistor is provided a voltage pumped higher than the supply voltage during read time to ensure that a small differential voltage on the digit lines is correctly read. A lower voltage is provided at sense time such that the isolation gate provides a higher resistance during sense time. During restore time, the isolation gate voltage is again raised above the operating voltage to minimize the effects of isolation transistor threshold voltage, Vt. In further embodiments, the higher voltage is only provided during restore time and the read and sense voltages are varied between the higher and lower voltage.
    Type: Grant
    Filed: August 14, 2001
    Date of Patent: September 3, 2002
    Assignee: Micron Technology, Inc.
    Inventors: Stephen R. Porter, George B. Raad, Stephen L. Casper