Patents by Inventor Rajiv V. Joshi

Rajiv V. Joshi 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: 7787284
    Abstract: A multi-threshold integrated circuit (IC) that may be supplied by multiple supplies, with an array of latches such as an array static random access memory (SRAM) cells and a CMOS SRAM with improved stability and reduced subthreshold leakage. Selected devices (NFETs and/or PFETs) in array cells and support logic, e.g., in the data path and in non-critical logic, are tailored for lower gate and subthreshold leakage. Normal base FETs have a base threshold and tailored FETs have a threshold above. In a multi-supply chip, circuits with tailored FETs are powered by an increased supply voltage.
    Type: Grant
    Filed: June 5, 2008
    Date of Patent: August 31, 2010
    Assignee: International Business Machines Corporation
    Inventors: Yuen H. Chan, Rajiv V. Joshi, Donald W. Plass
  • Patent number: 7783995
    Abstract: A system and method for scaling a circuit design to a new technology includes designating a first set of components including design scaled elements having a designed scaling in two dimensions to render the first set of components inactive for scaling of a second set of components. The second set of components includes pitch-matched circuits. The second set of components is scaled. Then, the second set of components is designated to render the second set of components inactive for scaling of the first set of components. The first set of components is scaled in accordance with a plurality of scale factors including scaling the design scaled elements in accordance with reference scale factors and scaling other components in the first set of components in accordance with one of the reference scale factors.
    Type: Grant
    Filed: March 8, 2007
    Date of Patent: August 24, 2010
    Assignee: International Business Machines Corporation
    Inventor: Rajiv V. Joshi
  • Patent number: 7777306
    Abstract: A semiconductor device includes a semiconductor material having two crystal orientations. The semiconductor material forms an active area of the device. A device channel is formed on the two crystal orientations, which include a first region formed in a first crystal orientation surface of the semiconductor material, and a second region formed in a second crystal orientation surface of the semiconductor material wherein the first crystal orientation surface forms an angle with the second crystal orientation surface and the device channel covers at least an intersection of the angle.
    Type: Grant
    Filed: March 6, 2007
    Date of Patent: August 17, 2010
    Assignee: International Business Machines Corporation
    Inventors: Louis C. Hsu, Rajiv V. Joshi, Xu Ouyang
  • Publication number: 20100201403
    Abstract: There is provided a method that includes comparing a voltage level (Vs1) of a lower voltage supply bus to a voltage level (Vs2) of a higher voltage supply bus, and routing current from the lower voltage supply bus to the higher voltage supply bus if Vs2<Vs1. The lower and higher voltage supply busses provide power to a complementary metal oxide semiconductor (CMOS) circuit. There is also provided a circuit that employs the method.
    Type: Application
    Filed: April 16, 2010
    Publication date: August 12, 2010
    Inventors: Rajiv V. Joshi, Louis L. Hsu
  • Patent number: 7774660
    Abstract: A row redundancy system is provided for replacing faulty wordlines of a memory array having a plurality of banks. The row redundancy system includes a remote fuse bay storing at least one faulty address corresponding to a faulty wordline of the memory array; a row fuse array for storing row fuse information corresponding to at least one bank of the memory array; and a copy logic module for copying at least one faulty address stored in the remote fuse bay into the row fuse array; wherein the copy logic module is programmed to copy the at least one faulty address into the row fuse information stored in the row fuse array corresponding to a predetermined number of banks in accordance with a selectable repair field size.
    Type: Grant
    Filed: June 2, 2008
    Date of Patent: August 10, 2010
    Assignee: International Business Machines Corporation
    Inventors: Louis L. Hsu, Gregory J. Fredeman, Rajiv V. Joshi, Toshiaki Kirihata
  • Patent number: 7768816
    Abstract: A design structure embodied in a machine readable medium for use in a design process, the design structure representing a novel semiconductor SRAM cell structure that includes at least two pull-up transistors, two pull-down transistors, and two pass-gate transistors. In one embodiment, the SRAM cell is an 8T SRAM cell structure implements a series gating feature for implementing Column Select (CS) and Row Select (WL) cell storage access with enhanced stability. Particularly, the 8-T approach adds two pass-gates, two series connected transistor devices connected at complementary nodes of two cross-coupled inverters, to control column select and row (word) select. In the other embodiment, the SRAM cell is a 9T SRAM cell structure includes a transmission gate to implement Column Select (CS) and Row Select (WL) cell storage access with enhanced stability. The 9-T approach adds three transistors to perform ANDING function to separate the row select and column select signal functions.
    Type: Grant
    Filed: December 7, 2007
    Date of Patent: August 3, 2010
    Assignee: International Business Machines Corporation
    Inventors: Rajiv V. Joshi, Yue Tan, Robert C. Wong
  • Patent number: 7751267
    Abstract: A programmable precharge circuit includes a plurality of transistors. Each transistor has a different threshold voltage from other transistors of the plurality of transistors. Each transistor is configured to connect a supply voltage to a node, and the node is selectively coupled to bitlines in accordance with a memory operation. Control logic is configured to enable at least one of the plurality of transistors to provide a programmable precharge voltage to the node in accordance with a respective threshold voltage drop from the supply voltage of one of the plurality of transistors.
    Type: Grant
    Filed: July 24, 2007
    Date of Patent: July 6, 2010
    Assignee: International Business Machines Corporation
    Inventors: Rajiv V. Joshi, Rouwaida Kanj, Jayakumaran Sivagnaname
  • Patent number: 7746709
    Abstract: In a memory circuit, data from all cells along a selected word line is read. Then, the read data is written back to half-selected cells and new data is written to the selected cells in the next cycle. In cases where a READ bit line (RBL) and WRITE bit line (WBL) are decoupled, RBL and WBL can be accessed simultaneously. Hence, the WRITE in the n-th cycle can be delayed to the n+1-th cycle as far as there is no data hazard such as reading data from memory before correct data are actually written to memory. As a result, there is no bandwidth loss, although the latency of the WRITE operation increases. WRITE stability issues in previous configurations with decoupled RBL and WBL are thus addressed.
    Type: Grant
    Filed: December 5, 2008
    Date of Patent: June 29, 2010
    Assignee: International Business Machines Corporation
    Inventors: Rajiv V. Joshi, Jae-Joon Kim, Rahul M. Rao
  • Patent number: 7733720
    Abstract: A method and system for determining element voltage selection control values for a storage device provides energy conservation in storage arrays while maintaining a particular performance level. The storage device is partitioned into multiple elements, which may be sub-arrays, rows, columns or individual storage cells. Each element has a corresponding virtual power supply rail that is provided with a selectable power supply voltage. At test time, digital control values are determined for selection circuits for each element that set the virtual power supply rail to the minimum power supply voltage, unless a higher power supply voltage is required for the element to meet performance requirements. The set of digital control values can then be programmed into a fuse or used to adjust a mask at manufacture, or supplied on media along with the storage device and loaded into the device at system initialization.
    Type: Grant
    Filed: November 16, 2007
    Date of Patent: June 8, 2010
    Assignee: International Business Machines Corporation
    Inventors: Rajiv V. Joshi, Jente B Kuang, Rouwaida N. Kanj, Sani R. Nassif, Hung Cai Ngo
  • Patent number: 7732922
    Abstract: The invention is directed to an improved semiconductor structure, such that within the same insulating layer, Cu interconnects embedded within the same insulating level layer have a different Cu grain size than other Cu interconnects embedded within the same insulating level layer.
    Type: Grant
    Filed: January 7, 2008
    Date of Patent: June 8, 2010
    Assignee: International Business Machines Corporation
    Inventors: Chih-Chao Yang, Louis C. Hsu, Rajiv V. Joshi
  • Patent number: 7733689
    Abstract: A memory cell for interconnection with READ and WRITE word lines and READ and WRITE bit lines includes a logical storage element such as a flip-flop formed by a first inverter and a second inverter cross-coupled to the first inverter. The storage element has first and second terminals and a storage element supply voltage terminal configured for interconnection with a first supply voltage. A WRITE access device is configured to selectively interconnect the first terminal to the WRITE bit line under control of the WRITE word line, and a pair of series READ access devices are configured to ground the READ bit line when the READ word line is active and the second terminal is at a high logical level. A logical “one” can be written to the storage element when a second supply voltage, greater than the first supply voltage, is applied to the WRITE word line, substantially without the use of a complementary WRITE bit line.
    Type: Grant
    Filed: July 17, 2008
    Date of Patent: June 8, 2010
    Assignee: International Business Machines Corporation
    Inventors: Keunwoo Kim, Rajiv V. Joshi, Vinod Ramadurai
  • Patent number: 7727888
    Abstract: An interconnect structure and a method for forming the same are described. Specifically, under the present invention, a gouge is created within a via formed in the interconnect structure before any trenches are formed. This prevents the above-mentioned trench damage from occurring. That is, the bottom surface of the trenches will have a roughness of less than approximately 20 nm, and preferably less than approximately 10 nm. In addition to the via, gouge and trench(es), the interconnect structure of the present invention includes at least two levels of metal wiring. Further, in a typical embodiment, the interconnect structure utilizes any dielectrics having a dielectric constant no greater than approximately 5.0.
    Type: Grant
    Filed: August 31, 2005
    Date of Patent: June 1, 2010
    Assignee: International Business Machines Corporation
    Inventors: Chih-Chao Yang, Louis C. Hsu, Rajiv V. Joshi
  • Publication number: 20100131259
    Abstract: A system and method for designing integrated circuits includes determining a target memory module for evaluation and improvement by evaluating performance variables of the memory module. The performance variables are statistically simulated over subset combinations of variables based on pin information for the module. Sensitivities of performance on yield to the variables in the subset combinations are determined. It is then determined whether yield of the target module is acceptable, and if the yield is not acceptable, a design which includes the target module is adjusted in accordance with the sensitivities to adjust the yield.
    Type: Application
    Filed: November 26, 2008
    Publication date: May 27, 2010
    Inventors: Rajiv V. Joshi, Rouwaida Kanj
  • Patent number: 7719135
    Abstract: There is provided a circuit for managing a multi-level power supply. The circuit includes a comparator that compares a voltage level (Vs1) of a lower voltage supply bus to a voltage level (Vs2) of a higher voltage supply bus, and a switch that routes current from the lower voltage supply bus to the higher voltage supply bus if Vs2<Vs1. The comparator is powered by the lower voltage supply bus, the lower and higher voltage supply busses provide power to an apparatus that includes a plurality of p-type metal oxide semiconductor devices in a common well, and the common well is electrically connected to the higher voltage supply bus.
    Type: Grant
    Filed: June 25, 2008
    Date of Patent: May 18, 2010
    Assignee: International Business Machines Corporation
    Inventors: Rajiv V Joshi, Louis L Hsu
  • Patent number: 7710796
    Abstract: A circuit and method includes first circuits powered by a first supply voltage and second circuits powered by a second supply voltage. A level shifter is coupled between the first circuits and the second circuits. The level shifter is configured to select a supply voltage output for a circuit including one of the first supply voltage and the second supply voltage in accordance an input signal, where the input signal depends on at least one of an operation to be performed and component performing the operation.
    Type: Grant
    Filed: November 6, 2007
    Date of Patent: May 4, 2010
    Assignee: International Business Machines Corporation
    Inventors: Scott R. Cottier, Sang Hoo Dhong, Rajiv V. Joshi, Juergen Pille, Osamu Takahashi
  • Patent number: 7709365
    Abstract: A method for forming a CMOS well structure including forming a plurality of first conductivity type wells over a substrate, each of the plurality of first conductivity type wells formed in a respective opening in a first mask. A cap is formed over each of the first conductivity type wells, and the first mask is removed. Sidewall spacers are formed on sidewalls of each of the first conductivity type wells. A plurality of second conductivity type wells are formed, each of the plurality of second conductivity type wells are formed between respective first conductivity type wells. A plurality of shallow trench isolations are formed between the first conductivity type wells and second conductive type wells. The plurality of first conductivity type wells are formed by a first selective epitaxial growth process, and the plurality of second conductivity type wells are formed by a second selective epitaxial growth process.
    Type: Grant
    Filed: October 23, 2006
    Date of Patent: May 4, 2010
    Assignee: International Business Machines Corporation
    Inventors: Wilfried Haensch, Terence B. Hook, Louis C. Hsu, Rajiv V. Joshi, Werner Rausch
  • Patent number: 7701801
    Abstract: A local on-chip programmable pulsewidth and delay generating circuit includes a clock generation circuit configured to receive a global clock signal and output a local clock signal. The clock generation circuit includes a pulse shaping portion which adjusts a pulse width of the global clock signal in accordance with at least one of a trailing edge delay and a leading edge delay. The leading edge delay is generated by a leading edge delay circuit, and the trailing edge delay is generated by a trailing edge delay circuit configured to apply a delay to a trailing edge of a pulse. The trailing edge delay circuit includes a delay chain having programmable stages of delay elements, each stage being independently controlled using control bits decoded from address latches.
    Type: Grant
    Filed: June 12, 2007
    Date of Patent: April 20, 2010
    Assignee: International Business Machines Corporation
    Inventors: Rajiv V. Joshi, Robert Maurice Houle, Kevin A. Batson
  • Patent number: 7681628
    Abstract: The present invention provides dynamic control of back gate bias on pull-up pFETs in a FinFET SRAM cell. A method according to the present invention includes providing a bias voltage to a back gate of at least one transistor in the SRAM cell, and dynamically controlling the bias voltage based on an operational mode (e.g., Read, Half-Select, Write, Standby) of the SRAM cell.
    Type: Grant
    Filed: April 12, 2006
    Date of Patent: March 23, 2010
    Assignee: International Business Machines Corporation
    Inventors: Rajiv V. Joshi, Keunwoo Kim, Edward J. Nowak, Richard Q. Williams
  • Publication number: 20090309622
    Abstract: A method and circuit for measuring internal pulses includes an enable circuit configured to receive a control signal from an on-chip built-in tester to enable measurement of internal circuits. A delay chain is configured to receive a pulse signal from an on-chip circuit component. Sampling latches each include a data input coupled between adjacent delay elements of the delay chain and synchronized with the clock signal such that a transition in the pulse signal is indicated by comparing adjacent digital values in an output sequence.
    Type: Application
    Filed: August 18, 2009
    Publication date: December 17, 2009
    Inventors: Rajiv V. Joshi, Robert L. Franch, Robert Maurice Houle, Kevin A. Batson
  • Publication number: 20090305472
    Abstract: A semiconductor device includes a semiconductor material having two crystal orientations. The semiconductor material forms an active area of the device. A device channel is formed on the two crystal orientations, which include a first region formed in a first crystal orientation surface of the semiconductor material, and a second region formed in a second crystal orientation surface of the semiconductor material wherein the first crystal orientation surface forms an angle with the second crystal orientation surface and the device channel covers at least an intersection of the angle.
    Type: Application
    Filed: August 19, 2009
    Publication date: December 10, 2009
    Inventors: Louis C. Hsu, Rajiv V. Joshi, Xu Ouyang