Patents Represented by Attorney Rose Alyssa Keagy
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Patent number: 8339839Abstract: 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: GrantFiled: January 31, 2012Date of Patent: December 25, 2012Assignee: Texas Instruments IncorporatedInventors: Theodore W. Houston, Anand Seshadri
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Patent number: 8331187Abstract: 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: GrantFiled: February 12, 2009Date of Patent: December 11, 2012Assignee: Texas Instruments IncorporatedInventors: Theodore W. Houston, Michael P Clinton, Bryan D Sheffield
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Patent number: 8329588Abstract: 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: GrantFiled: November 23, 2011Date of Patent: December 11, 2012Assignee: Texas Instruments IncorporatedInventors: Scott R. Summerfelt, Ted S. Moise, Gul B. Basim
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Patent number: 8324742Abstract: 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: GrantFiled: August 1, 2008Date of Patent: December 4, 2012Assignee: Texas Instruments IncorporatedInventors: Scott R. Summerfelt, Stephen A. Meisner, John B. Robbins
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Patent number: 8325511Abstract: 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: GrantFiled: April 21, 2010Date of Patent: December 4, 2012Assignee: Texas Instruments IncorporatedInventor: Anand Seshadri
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Patent number: 8324665Abstract: 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: GrantFiled: April 21, 2009Date of Patent: December 4, 2012Assignee: Texas Instruments IncorporatedInventor: Theodore W. Houston
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Patent number: 8320165Abstract: 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: GrantFiled: November 21, 2011Date of Patent: November 27, 2012Assignee: Texas Instrument IncorporatedInventors: Robert R. Garcia, Theodore W. Houston
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Patent number: 8315086Abstract: 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: GrantFiled: November 21, 2011Date of Patent: November 20, 2012Assignee: Texas Instruments IncorporatedInventor: Theodore W. Houston
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Patent number: 8310860Abstract: 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: GrantFiled: November 21, 2011Date of Patent: November 13, 2012Assignee: Texas Instruments IncorporatedInventor: Theodore W. Houston
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Patent number: 8305798Abstract: 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: GrantFiled: July 13, 2010Date of Patent: November 6, 2012Assignee: Texas Instruments IncorporatedInventor: Xiaowei Deng
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Patent number: 8301431Abstract: 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: GrantFiled: December 30, 2008Date of Patent: October 30, 2012Assignee: Texas Instruments IncorporatedInventors: Keerthinarayan P. Heragu, Theodore W. Houston, Anand Seshadri, Hugh T. Mair
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Patent number: 8300451Abstract: 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: GrantFiled: March 30, 2010Date of Patent: October 30, 2012Assignee: Texas Instruments IncorporatedInventors: Hugh T. Mair, Theodore W. Houston
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Patent number: 8300446Abstract: 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: GrantFiled: December 13, 2010Date of Patent: October 30, 2012Assignee: Texas Instruments IncorporatedInventor: Saim Ahmad Qidwai
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Patent number: 8296628Abstract: 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: GrantFiled: February 3, 2010Date of Patent: October 23, 2012Assignee: Texas Instruments IncorporatedInventor: Sudhir K. Madan
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Patent number: 8268696Abstract: 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: GrantFiled: December 9, 2010Date of Patent: September 18, 2012Assignee: Texas Instruments IncorporatedInventors: Scott R. Summerfelt, Stephen A. Meisner, John B. Robbins
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Patent number: 8247855Abstract: 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: GrantFiled: September 12, 2006Date of Patent: August 21, 2012Assignee: Texas Instruments IncorporatedInventor: Scott R. Summerfelt
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Patent number: 8238158Abstract: 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: GrantFiled: August 4, 2010Date of Patent: August 7, 2012Assignee: Texas Instruments IncorporatedInventors: Douglas Edward Shelton, Bruce Lynn Pickelsimer, John Howard MacPeak
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Patent number: 8233341Abstract: 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: GrantFiled: September 1, 2009Date of Patent: July 31, 2012Assignee: Texas Instruments IncorporatedInventors: Xiaowei Deng, Wah Kit Loh
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Patent number: 8228749Abstract: 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: GrantFiled: June 4, 2010Date of Patent: July 24, 2012Assignee: Texas Instruments IncorporatedInventors: Xiaowei Deng, Wah Kit Loh, Lakshmikantha V. Holla, Parvinder Kumar Rana
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Patent number: 8218376Abstract: 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: GrantFiled: April 21, 2010Date of Patent: July 10, 2012Assignee: Texas Instruments IncorporatedInventors: Anand Seshadri, Hugh Thomas Mair