Patents Assigned to STMicroelectronics
  • Patent number: 5848018
    Abstract: A memory-row selector includes an address input terminal, a mode terminal, and even-row-select and odd-row-select terminals. While a test signal level occupies the mode terminal (ie., during a test mode), the selector places either an active level or an inactive level on both of the even-row-select and odd-row-select terminals. An active level on both of the select terminals enables both even-row and odd-row word lines, and allows writing to or reading from memory cells in both odd and even rows. An inactive level on both of the select terminals disables both even-row and odd-row word lines, including the word line coupled to the addressed memory cell.
    Type: Grant
    Filed: September 10, 1997
    Date of Patent: December 8, 1998
    Assignee: STMicroelectronics, Inc.
    Inventor: David C. McClure
  • Patent number: 5847457
    Abstract: A method is provided for forming a contact opening or via of a semiconductor integrated circuit, and an integrated circuit formed according to the same. A first metal region is formed over an underlying region. A first insulating layer is formed over the integrated circuit. A second insulating layer is then formed over the first insulating layer. A portion of the second insulating layer is etched to expose a portion of the first insulating layer wherein the exposed first insulating layer and the remaining second insulating layer form a substantially planar surface. A metal oxide layer is formed over the exposed first insulating layer and the remaining second insulating layer. A photoresist layer is formed and patterned over the metal oxide layer. The metal oxide layer is then selectively etched to form a via exposing a portion of the first insulating layer. The first insulating layer in the via is then selectively etched to expose a portion of the first metal region.
    Type: Grant
    Filed: October 24, 1996
    Date of Patent: December 8, 1998
    Assignee: STMicroelectronics, Inc.
    Inventors: Fusen E. Chen, Fu-Tai Liou, Girish A. Dixit
  • Patent number: 5847460
    Abstract: A method is provided of forming a small geometry via or contact of a semiconductor integrated circuit, and an integrated circuit formed according to the same, is disclosed. According to a first disclosed embodiment, an opening is formed partially through an insulating layer overlying a conductive region. Sidewall spacers are formed along the sidewalls of the opening. The remaining insulating layer is etched to expose the underlying conductive region. The contact dimension of the opening is smaller than the opening which can be printed from modern photolithography techniques. According to an alternate embodiment, the opening in the insulating layer expose the underlying conductive region. A polysilicon layer is formed over the insulating layer and in the opening. The polysilicon is oxidized to form a thick oxide in the opening and is etched back to form oxidized polysilicon sidewall spacers which decrease the contact dimension of the opening.
    Type: Grant
    Filed: December 19, 1995
    Date of Patent: December 8, 1998
    Assignee: STMicroelectronics, Inc.
    Inventors: Fu-Tai Liou, Mehdi Zamanian
  • Patent number: 5847465
    Abstract: A method for fabrication of metal to semiconductor contacts results in sloped sidewalls in contact regions. An oxide layer is deposited and etched back to form sidewall spacers. A glass layer is then deposited and heated to reflow. After reflow, an etch back of the glass layer results is sloped sidewalls at contact openings and over steps.
    Type: Grant
    Filed: May 8, 1995
    Date of Patent: December 8, 1998
    Assignee: STMicroelectronics, Inc.
    Inventors: Fu-Tai Liou, Yu-Pin Han
  • Patent number: 5845059
    Abstract: A data input circuit is used in a memory device having an externally accessible data pin. The data input circuit includes first and second data output terminals and a test terminal that receives a test signal. A data converter is coupled to the first and second data output terminals and to the test terminal, and places complementary signal levels on the first and second data output terminals when the test signal is absent from the test terminal, and places a same signal level on both the first and second data output terminals when the test signal is present on the test terminal. The data input circuit may include an input terminal that is coupled to the data pin, where the data converter is coupled to the input terminal.
    Type: Grant
    Filed: January 19, 1996
    Date of Patent: December 1, 1998
    Assignee: STMicroelectronics, Inc.
    Inventor: David C. McClure
  • Patent number: 5841789
    Abstract: A method and apparatus for testing and programming signal timing are disclosed which can be incorporated into an integrated circuit device utilizing on-chip timed command signals and pulses. The method of the invention enables nonpermanent testing and retesting of a device at various operational speeds during production testing. During retesting, temporary signal delays are selectively introduced into the circuit of a device which failed a previous test due to non-repairable errors. Once a device passes the production test error-free or with repairable errors, the temporary signal delays are permanently programmed into the device. Specifically, the method utilizes one or a plurality of mode control circuits and test voltage input terminals to nonpermanently select signal delays which may be identified and permanently enabled at a later time.
    Type: Grant
    Filed: May 9, 1996
    Date of Patent: November 24, 1998
    Assignee: STMicroelectronics, Inc.
    Inventor: David Charles McClure
  • Patent number: 5841784
    Abstract: A method and circuits for coupling a memory embedded in an integrated circuit to interconnect pads during a memory test mode is disclosed. The integrated circuit contains a processor, an embedded memory and a switching circuit for: (1) temporary coupling the memory array and memory peripheral circuits, coupled to the processor during normal operation mode of the circuit, to the interconnect pads of the memory during a memory test mode; (2) and decoupling the interconnect pads from the memory array and peripheral circuits, after the memory is tested, and coupling the memory array and peripheral circuits to the processor.
    Type: Grant
    Filed: April 2, 1996
    Date of Patent: November 24, 1998
    Assignee: STMicroelectronics, Inc.
    Inventors: Tsiu Chiu Chan, Lawrence P. Eng
  • Patent number: 5841195
    Abstract: A method is provided for forming contact via in an integrated circuit. Initially, a first buffer layer is formed over an insulating layer in an integrated circuit. The first buffer layer has a different etch rate from the insulating layer. A second buffer layer is then formed over the first buffer layer, with the second buffer layer having an etch rate which is faster than the first buffer layer. An isotropic etch is performed to create an opening through the second buffer layer and a portion of the first buffer layer. Because the second buffer layer etches faster than the first buffer layer, the slant of the sideswalls of the opening can be controlled. An anisotropic etch is then performed to complete formation of the contact via.
    Type: Grant
    Filed: May 24, 1995
    Date of Patent: November 24, 1998
    Assignee: STMicroelectronics, Inc.
    Inventors: Yih-Shung Lin, Lun-Tseng Lu, Fu-Tai Liou, Che-Chia Wei, John Leonard Walters
  • Patent number: 5841709
    Abstract: A memory device includes an array of matrix memory cells that each correspond to a matrix location within the matrix array, an array of redundant memory cells that each correspond to a redundant location within the redundant array, and address and test circuitry. During a first test mode that is performed before any redundant cells have been mapped to the addresses of matrix locations, the address and test circuitry simultaneously addresses all of the matrix locations and selects all of the redundant memory cells. During a second test mode that is performed after the first test mode, the address and test circuitry simultaneously addresses all of the matrix locations and selects only those redundant memory cells that are mapped to the addresses of matrix locations. Typically, the redundant memory cells are so mapped to replace defective matrix memory cells.
    Type: Grant
    Filed: November 27, 1996
    Date of Patent: November 24, 1998
    Assignee: STMicroelectronics, Inc.
    Inventor: David C. McClure
  • Patent number: 5837613
    Abstract: A method for planarizing integrated circuit topographies, wherein, after a first layer of spin-on glass is deposited, a layer of low-temperature oxide is deposited before a second layer of spin-on glass.
    Type: Grant
    Filed: November 24, 1997
    Date of Patent: November 17, 1998
    Assignee: STMicroelectronics, Inc.
    Inventors: Alex Kalnitsky, Yih-Shung Lin
  • Patent number: 5834360
    Abstract: A method is provided for forming an isolation structure at a semiconducting surface of a body, and the isolation structure formed thereby. A masking layer is formed over selected regions of the substrate surface; the masking layer preferably comprising a nitride layer overlying a pad oxide layer. The masking layer is patterned and etched to form openings exposing selected regions of the substrate surface. Recesses are formed into the substrate in the openings. Preferably a portion of the pad oxide layer is isotropically etched under the nitride layer forming an undercut region. An etch stop layer is formed over the substrate in the recesses filling in the undercut along the sidewalls. A second masking layer, preferably of nitride is formed over the etch stop layer and anisotropically etched to form nitride sidewalls in the openings. The etch stop layer may be etched away from the horizontal surfaces.
    Type: Grant
    Filed: July 31, 1996
    Date of Patent: November 10, 1998
    Assignee: STMicroelectronics, Inc.
    Inventors: Mark R. Tesauro, Frank R. Bryant
  • Patent number: 5832596
    Abstract: A method for forming a package for an integrated circuit in which a plurality of conduction paths are formed on a first board and on a second board. Holes are formed in the first board and the second board wherein the holes are adapted for receiving pins. The holes are aligned and the first board is coupled to the second board using an adhesive.
    Type: Grant
    Filed: December 31, 1996
    Date of Patent: November 10, 1998
    Assignee: STMicroelectronics, Inc.
    Inventor: Anthony Man-Chong Chiu
  • Patent number: 5834966
    Abstract: An integrated circuit includes a plurality of MOSFETs on a substrate. A plurality of sensing MOSFETs are used to generate a plurality of comparison signals based upon comparing signals related to the sensed initial threshold voltages to respective reference voltages from a spread of high to low reference voltage values. The MOSFETs are biased to have a desired effective threshold voltage based upon the plurality of comparison signals. Logic decoding circuits accept the plurality of comparison signals and generate at least one bias control signal. Bias circuits are responsive to the at least one bias control signal for generating a desired bias voltage from among a plurality of bias voltages having a spread of high to low bias voltage values to thereby bias the plurality of MOSFETs to the desired effective threshold voltage. Method aspects of the invention are also disclosed.
    Type: Grant
    Filed: December 8, 1996
    Date of Patent: November 10, 1998
    Assignee: STMicroelectronics, Inc.
    Inventors: Jason Siucheong So, Tsiu Chiu Chan
  • Patent number: 5834826
    Abstract: A circuit, and method of operation, allows initial operation of a parasitic transistor in a junction isolated integrated circuit. The initial operation activates elements that produce a turn-on drive signal to a power transistor that has a part in the parasitic transistor, resulting in ending the operation of the parasitic transistor. A low side driver, such as an N channel DMOS, in a bridge circuit for an inductive load is arranged with a sinker region close by so that the sinker region acts as a preferred collector of a parasitic transistor that also includes a region of the low side driver as an emitter. The circuit includes logic that processes signals developed by initial operation of the parasitic transistor to develop the turn-on drive signal to the particular low side driver without affecting other low side drivers in the integrated circuit and before any other devices in the integrated circuit are caused to sink any appreciable current in parasitic transistor operation.
    Type: Grant
    Filed: May 8, 1997
    Date of Patent: November 10, 1998
    Assignee: STMicroelectronics, Inc.
    Inventor: Paolo Menegoli
  • Patent number: 5835427
    Abstract: Accelerated failure of processing defects in an integrated circuit memory device is brought about by asserting all wordlines of the memory device to enable all passgates for a plurality of memory cells. Then all bitlines are pulled low to pull low all internal nodes of the plurality memory cells. All active devices in the memory device are turned off or limited to linear region operation. This allows a supervoltage to be applied to the wordlines with internal nodes of the memory cells held low by the bitlines, stressing an oxide barrier between memory cells and wordlines without damaging active devices due to the supervoltage.
    Type: Grant
    Filed: December 22, 1993
    Date of Patent: November 10, 1998
    Assignee: STMicroelectronics, Inc.
    Inventor: David Charles McClure
  • Patent number: 5831326
    Abstract: A method for fabricating a resistive load element for a semiconductor device can be used with standard semiconductor processes. A layer of second level poly is deposited and lightly doped P-type. A resist mask is used to dope selected regions of the poly layer N-type. The poly layer is then patterned to define conductors and resistive load elements. The resistive load elements are formed by back-to-back PN diodes formed at the interfaces between the P-type and N-type regions.
    Type: Grant
    Filed: November 3, 1995
    Date of Patent: November 3, 1998
    Assignee: STMicroelectronics, Inc.
    Inventors: Tsiu Chiu Chan, William A. Bishop
  • Patent number: 5831446
    Abstract: A process monitor test chip and methodology allows process-related manufacturing defects to be quickly identified and isolated. A basic circuit block of a test chip having a number of inverter cells serially connected with a corresponding number of observation points before the input of each inverter cell provides for the inverter cells in the basic circuit block to be probed and thus observed by e-beam technology. Any required number of basic circuit blocks may be serially connected end to end to constitute a chain circuit. Within the test chip itself, a plurality of chain circuits may be connected serially or in parallel to accomplish different testing goals. By controlling an input signal and a control signal of a multiplexing element associated with each chain circuit, the plurality of chain circuits can be forced into a serial connection or a parallel connection.
    Type: Grant
    Filed: July 12, 1996
    Date of Patent: November 3, 1998
    Assignee: STMicroelectronics, Inc.
    Inventors: Jason S. So, Tam T. Le, Milind Asnani
  • Patent number: 5831897
    Abstract: A memory cell in which data is written and read from a pass gate. The memory cell has a connection to a first pass gate, connecting the memory cell to a bit line. Additionally, the memory cell has a second pass gate connecting the memory cell to a complementary bit line. The pass gates are controlled by a word line and a complementary word line.
    Type: Grant
    Filed: December 12, 1996
    Date of Patent: November 3, 1998
    Assignee: STMicroelectronics, Inc.
    Inventor: Robert Louis Hodges
  • Patent number: 5831891
    Abstract: A non-volatile memory device having optimized management of data transmission lines, having the particularity that it comprises at least one bidirectional internal bus that runs from one end of the memory device to the other, one or more source structures that exist externally and internally to the memory device, and a timer means. The timer means is adapted to time-control the independent and exclusive access of the external and internal source structures, within a same memory cycle, to the internal bus for the transmission of data, controls, and functions, from one end of the memory to the other over the internal bus.
    Type: Grant
    Filed: March 7, 1997
    Date of Patent: November 3, 1998
    Assignee: STMicroelectronics S.r.l.
    Inventors: Luigi Pascucci, Antonio Barcella
  • Patent number: 5831457
    Abstract: The present invention provides an input buffer circuit for reducing false transitions within a circuit. The input buffer circuit includes an input pad for receiving an input voltage, an input buffer having an input and a circuit for modifying a voltage entering the input buffer to track changes in a power supply voltage relative to a voltage at the input pad. The circuit is connected in series between the input pad and the input the input buffer.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: November 3, 1998
    Assignee: STMicroelectronics, Inc.
    Inventor: David Charles McClure