Patents Represented by Attorney Rose Alyssa Keagy
  • Patent number: 8339839
    Abstract: A first integrated circuit containing a single sided write SRAM cell array, each SRAM cell having a bit passgate and an auxiliary bit-bar driver transistor. A process of operating the first integrated circuit including a single sided read operation in which source nodes of the auxiliary drivers in both addressed cells and half-addressed cells are floated. A second integrated circuit containing an SRAM cell array, in which each SRAM cell includes a bit-side write passgate, a bit-bar-side read passgate and a bit-bar auxiliary driver transistor. A process of operating the second integrated circuit including a single sided read operation in which source nodes of the auxiliary drivers in both addressed cells and half-addressed cells are biased to a low bias voltage.
    Type: Grant
    Filed: January 31, 2012
    Date of Patent: December 25, 2012
    Assignee: Texas Instruments Incorporated
    Inventors: Theodore W. Houston, Anand Seshadri
  • Patent number: 8331187
    Abstract: The present invention describes circuitry and a method of providing a low power WRITE mode of operation for an integrated circuit comprising an SRAM memory to provide a reduced IDDQ relative to the IDDQ of a full active mode. In one aspect, the circuitry includes an SRAM memory array, mode control circuitry coupled to the array and configured to alter a supply voltage level to the SRAM array based on a mode of operation. The circuitry also includes control inputs coupled to the mode control circuitry for selecting one of the low power write mode, the full active mode, and optionally a retention mode of operation. The mode control circuitry is configured to receive the control inputs to select one of the three modes of operation, and to alter one or more supply voltage levels to the array, for example, the Vss supply voltage using a Vss supply circuit and the Vdd supply voltage using a Vdd supply circuit, based on the selected mode of operation.
    Type: Grant
    Filed: February 12, 2009
    Date of Patent: December 11, 2012
    Assignee: Texas Instruments Incorporated
    Inventors: Theodore W. Houston, Michael P Clinton, Bryan D Sheffield
  • Patent number: 8329588
    Abstract: A method for forming a hydrogen barrier layer that overlies ferroelectric capacitors and a buffer region but is removed from a portion of the logic region.
    Type: Grant
    Filed: November 23, 2011
    Date of Patent: December 11, 2012
    Assignee: Texas Instruments Incorporated
    Inventors: Scott R. Summerfelt, Ted S. Moise, Gul B. Basim
  • Patent number: 8324742
    Abstract: An IC alignment mark in a contact metal layer for use under an opaque layer, and a process for forming the alignment mark, are disclosed. The alignment mark includes contact metal fields, each several microns wide, with an array of PMD pillars in the interior, formed during contact etch, contact metal deposition and selective contact metal removal processes. The pillars are arrayed such that all exposed surfaces of the contact metal are planar. One configuration is a rectangular array in which every other row is laterally offset by one-half of the column spacing. Horizontal dimensions of the pillars are selected to maximize the contact metal fill factor, while providing sufficient adhesion to the underlying substrate during processing. The contact metal is at least 15 nanometers lower than the PMD layer surrounding the alignment mark, as a result of the contact metal removal process.
    Type: Grant
    Filed: August 1, 2008
    Date of Patent: December 4, 2012
    Assignee: Texas Instruments Incorporated
    Inventors: Scott R. Summerfelt, Stephen A. Meisner, John B. Robbins
  • Patent number: 8325511
    Abstract: Bias circuitry for a static random-access memory (SRAM) with a retain-till-accessed (RTA) mode. The memory is constructed of multiple memory array blocks, each including SRAM cells of the 8-T or 10-T type, with separate read and write data paths. Bias devices are included within each memory array block, for example associated with individual columns, and connected between a reference voltage node for cross-coupled inverters in each memory cell in the associated column or columns, and a ground node. In a normal operating mode, a switch transistor connected in parallel with the bias devices is turned on, so that the ground voltage biases the cross-coupled inverters in each cell. In the RTA mode, the switch transistors are turned off, allowing the bias devices to raise the reference bias to the cross-coupled inverters, reducing power consumed by the cells in that mode.
    Type: Grant
    Filed: April 21, 2010
    Date of Patent: December 4, 2012
    Assignee: Texas Instruments Incorporated
    Inventor: Anand Seshadri
  • Patent number: 8324665
    Abstract: An integrated circuit containing logic transistors and an array of SRAM cells in which the logic transistors are formed in semiconductor material with one crystal orientation and the SRAM cells are formed in a second semiconductor layer with another crystal orientation. A process of forming an integrated circuit containing logic transistors and an array of SRAM cells in which the logic transistors are formed in a top semiconductor layer with one crystal orientation and the SRAM cells are formed in an epitaxial semiconductor layer with another crystal orientation. A process of forming an integrated circuit containing logic transistors and an array of SRAM cells in which the SRAM cells are formed in a top semiconductor layer with one crystal orientation and the logic transistors are formed in an epitaxial semiconductor layer with another crystal orientation.
    Type: Grant
    Filed: April 21, 2009
    Date of Patent: December 4, 2012
    Assignee: Texas Instruments Incorporated
    Inventor: Theodore W. Houston
  • Patent number: 8320165
    Abstract: An integrated circuit containing an SRAM array having a strap row. The strap row has a substrate contact structure that includes a substrate contact plug and a tap layer.
    Type: Grant
    Filed: November 21, 2011
    Date of Patent: November 27, 2012
    Assignee: Texas Instrument Incorporated
    Inventors: Robert R. Garcia, Theodore W. Houston
  • Patent number: 8315086
    Abstract: An integrated circuit containing an SRAM array having a strap row and an SRAM cell row. The strap row includes a tap connecting region that connects two columnar regions of a first polarity well. The strap row also includes a well tap active area in a tap connecting well region. The well tap active area includes a tap layer and a well contact plug that is disposed on the top surface of the tap layer.
    Type: Grant
    Filed: November 21, 2011
    Date of Patent: November 20, 2012
    Assignee: Texas Instruments Incorporated
    Inventor: Theodore W. Houston
  • Patent number: 8310860
    Abstract: An integrated circuit containing an SRAM array having a strap row. The strap row has a well tap active area that partially overlaps adjacent first polarity wells and a second polarity well that is located between the adjacent first polarity wells. A well contact plug is disposed on a top surface of a tap layer located within the well tap active area.
    Type: Grant
    Filed: November 21, 2011
    Date of Patent: November 13, 2012
    Assignee: Texas Instruments Incorporated
    Inventor: Theodore W. Houston
  • Patent number: 8305798
    Abstract: A solid-state memory in which write assist circuitry is implemented within each memory cell. Each memory cell includes a storage element, such as a pair of cross-coupled inverters, and an equalization gate connected between the storage nodes of the storage element. The equalization gate may be realized by two transistors in series, or as a double-gate transistor. The equalization gate is controlled by a word line indicating selection of the row containing the cell in combination with a column select signal indicating selection of the column containing the cell in a write cycle. Upon a write to a selected cell, both gates are turned on, connecting the storage nodes of the cell to one another and assisting the write of the opposite date state from that previously stored.
    Type: Grant
    Filed: July 13, 2010
    Date of Patent: November 6, 2012
    Assignee: Texas Instruments Incorporated
    Inventor: Xiaowei Deng
  • Patent number: 8301431
    Abstract: A method of accelerating a Monte Carlo (MC) simulation for a system including a first component having a first input parameter and a second component having a second input parameter. The simulation model provided includes a first component model including a first model parameter corresponding to the first input parameter and a second component model having a second model parameter corresponding to the second input parameter. A first acceleration factor for the first component and a second acceleration factor for the second component are calculated based on at least the respective number of instances. A first scaled distribution is computed from the first distribution and a second scaled distribution is computed from the second distribution based on the respective acceleration factors. The MC simulation for the system is run, wherein values for the first model parameter value and second model parameter value are obtained based on the respective scaled distributions.
    Type: Grant
    Filed: December 30, 2008
    Date of Patent: October 30, 2012
    Assignee: Texas Instruments Incorporated
    Inventors: Keerthinarayan P. Heragu, Theodore W. Houston, Anand Seshadri, Hugh T. Mair
  • Patent number: 8300451
    Abstract: An integrated circuit having a static random access memory (SRAM) includes an array of SRAM cells arranged in rows and columns having a write word line and a read/write word line connected to provide row access to the array of SRAM cells. The SRAM also includes a coupling capacitance connected between the write word line and a detachable allocation of the read/write word line as well as an overdrive module connected to charge the coupling capacitance and provide an overdrive voltage on the detachable allocation of the read/write word line during activation of the write word line. A method of operating an integrated circuit having an SRAM includes providing an overdrive voltage on the detachable allocation of the read/write word line corresponding to a charge redistribution across the coupling capacitance during part of a write cycle.
    Type: Grant
    Filed: March 30, 2010
    Date of Patent: October 30, 2012
    Assignee: Texas Instruments Incorporated
    Inventors: Hugh T. Mair, Theodore W. Houston
  • Patent number: 8300446
    Abstract: A ferroelectric random access memory (FRAM) with reduced cycle time. During a read cycle, plate line voltages are boosted to a voltage to both transfer charge from the selected row of FRAM cells to corresponding bit lines, and to fully polarize a data state in the selected FRAM cells. In one embodiment of the invention, the fully polarized data states is present in those cells that previously stored that data state; for those cells storing the opposite state, a write-back pulse is executed. In another embodiment of the invention, the fully polarized data state results for each of the selected memory cells, by applying a plate line boost voltage of a higher magnitude. Those cells that are to store the opposite data state, as may be determined following error correction, are written back with that data state.
    Type: Grant
    Filed: December 13, 2010
    Date of Patent: October 30, 2012
    Assignee: Texas Instruments Incorporated
    Inventor: Saim Ahmad Qidwai
  • Patent number: 8296628
    Abstract: A solid-state memory such as a ferroelectric random access memory (FeRAM) with multiplexed internal data bus and reduced power consumption on data transfer. The memory stores data in the form of multi-byte data words with error correction coding (ECC). In a page mode read/write operation, data states stored in memory cells of the selected row are sensed by sense amplifiers arranged in first and second banks, which are associated with first and second groups of columns. The first bank of sense amplifiers, associated with the first group of columns and containing the ECC value, are coupled to to the internal bus, followed by coupling the second bank of sense amplifiers associated with the second group of columns to the internal bus. The internal bus is then placed in tri-state, following which the internal data bus is driven with data to be written into the second group of columns in that same row, that data latched into the second bank of sense amplifiers.
    Type: Grant
    Filed: February 3, 2010
    Date of Patent: October 23, 2012
    Assignee: Texas Instruments Incorporated
    Inventor: Sudhir K. Madan
  • Patent number: 8268696
    Abstract: An IC alignment mark in a contact metal layer for use under an opaque layer, and a process for forming the alignment mark, are disclosed. The alignment mark includes contact metal fields, each several microns wide, with an array of PMD pillars in the interior, formed during contact etch, contact metal deposition and selective contact metal removal processes. The pillars are arrayed such that all exposed surfaces of the contact metal are planar. One configuration is a rectangular array in which every other row is laterally offset by one-half of the column spacing. Horizontal dimensions of the pillars are selected to maximize the contact metal fill factor, while providing sufficient adhesion to the underlying substrate during processing. The contact metal is at least 15 nanometers lower than the PMD layer surrounding the alignment mark, as a result of the contact metal removal process.
    Type: Grant
    Filed: December 9, 2010
    Date of Patent: September 18, 2012
    Assignee: Texas Instruments Incorporated
    Inventors: Scott R. Summerfelt, Stephen A. Meisner, John B. Robbins
  • Patent number: 8247855
    Abstract: A ferroelectric device employs ferroelectric electrodes as local interconnect(s). One or more circuit features are formed within or on a semiconductor body. A first dielectric layer is formed over the semiconductor body. Lower contacts are formed within the first dielectric layer. A bottom electrode is formed over the first dielectric layer and on the lower contacts. A ferroelectric layer is formed on the bottom electrode. A top electrode is formed on the ferroelectric layer. A second dielectric layer is formed over the first dielectric layer. Upper contacts are formed within the second dielectric layer and in contact with the top electrode. Conductive features are formed on the upper contacts.
    Type: Grant
    Filed: September 12, 2006
    Date of Patent: August 21, 2012
    Assignee: Texas Instruments Incorporated
    Inventor: Scott R. Summerfelt
  • Patent number: 8238158
    Abstract: An electrically programmable non-volatile memory array and associated circuitry, including programming circuitry that adaptively senses completed programming of a selected memory cell. A programming bit line driver is connected to the bit line, and a first transistor has its source/drain path connected in series with the memory cell, and its gate connected to the output of the current comparator. As the MOS transistor in the selected cell becomes programmed, its drain current drawn from the bit line driver decays, and a remainder current into the current comparator increases. Upon the remainder current exceeding the reference current, the comparator turns off the first transistor; a second transistor connected between the source and drain of the cell transistor is turned on. In another approach, a summed current controls the gates of the first and second transistors. Programming terminates, and over-programming is avoided.
    Type: Grant
    Filed: August 4, 2010
    Date of Patent: August 7, 2012
    Assignee: Texas Instruments Incorporated
    Inventors: Douglas Edward Shelton, Bruce Lynn Pickelsimer, John Howard MacPeak
  • Patent number: 8233341
    Abstract: A parametric test circuit is disclosed (FIG. 6). The test circuit includes a latch circuit having true and complementary terminals. A first access transistor (206) has a current path connected between the true terminal and a first access terminal (214) and has a first control terminal. A second access transistor (208) has a current path connected between the complementary terminal and a second access terminal (216) and has a second control terminal connected to the first control terminal. A first pass gate (604) has a current path connected between the first access terminal (214) and a third access terminal (XBLT) and has a third control terminal. A second pass gate (606) has a current path connected between the second access terminal (216) and a fourth access terminal (XBLB) and has a fourth control terminal connected to the third control terminal.
    Type: Grant
    Filed: September 1, 2009
    Date of Patent: July 31, 2012
    Assignee: Texas Instruments Incorporated
    Inventors: Xiaowei Deng, Wah Kit Loh
  • Patent number: 8228749
    Abstract: A static random access memory (SRAM) and method of evaluating the same for cell stability, write margin, and read current margin. The memory is constructed so that bit line precharge can be disabled, and so that complementary bit lines for each column of cells can float during memory operations. The various tests are performed by precharging the bit lines for a column, then floating the bit lines, and while the bit lines are floating, pulsing the word lines of one or more selected cells to cause the voltage on one of the bit lines to discharge. The discharged bit line voltage is then applied to another cell, which is then read in a normal read operation to determine whether its state changed due to the discharged bit line voltage. The memory can be characterized for cell stability, write margin, and read current margin in this manner; the method can also be adapted into a manufacturing margin screen, or used in failure analysis.
    Type: Grant
    Filed: June 4, 2010
    Date of Patent: July 24, 2012
    Assignee: Texas Instruments Incorporated
    Inventors: Xiaowei Deng, Wah Kit Loh, Lakshmikantha V. Holla, Parvinder Kumar Rana
  • Patent number: 8218376
    Abstract: Bias circuitry for a static random-access memory (SRAM) with a retain-till-accessed (RTA) mode. The memory is constructed of multiple memory array blocks, each including SRAM cells formed of array transistors; functional and other circuitry outside of the array are formed of core transistors, constructed differently from the array transistors. Bias devices are included within each memory array block, the bias devices constructed as one or more array transistors. The bias devices for a memory array block may be connected in parallel with one another. In the RTA mode, the bias devices drop the power supply voltage differential across each of the SRAM cells. In a normal operating mode, a core transistor serves as a switch, shorting out the bias devices so that the full power supply differential appears across the SRAM cells.
    Type: Grant
    Filed: April 21, 2010
    Date of Patent: July 10, 2012
    Assignee: Texas Instruments Incorporated
    Inventors: Anand Seshadri, Hugh Thomas Mair