Patents by Inventor Myoungho Lim

Myoungho Lim 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: 6924997
    Abstract: A ferroelectric memory 636 includes a group of memory cells (645, 12, 201, 301, 401, 501), each cell having a ferroelectric memory element (44, 218, etc.), a drive line (122, 322, 422, 522 etc.) on which a voltage for writing information to the group of memory cells is placed, a bit line (25, 49, 125, 325, 425, 525, etc.) on which information to be read out of the group of memory cells is placed, a preamplifier (20, 42, 120, 320, 420, etc.) between the memory cells and the bit line, a set switch (14, 114, 314, 414, 514, etc.) connected between the drive line and the memory cells, and a reset switch (16, 116, 316, 416, 516, etc.) connected to the memory cells in parallel with the preamplifier. The memory is read by placing a voltage less than the coercive voltage of the ferroelectric memory element across a memory element. Prior to reading, noise from the group of cells is discharged by grounding both electrodes of the ferroelectric memory element.
    Type: Grant
    Filed: September 25, 2001
    Date of Patent: August 2, 2005
    Assignees: Symetrix Corporation, Matsushita Electric Industrial Co., Ltd.
    Inventors: Zheng Chen, Vikram Joshi, Myoungho Lim, Carlos A. Paz de Araujo, Larry D. McMillan, Yoshihisa Kato, Tatsuo Otsuki, Yasuhiro Shimada
  • Publication number: 20050127874
    Abstract: Embodiments of the present invention are directed to a method and apparatus for multiple battery cell management. In one embodiment, a solid state relay is used instead of a mechanical relay in a BMS. The SSR is smaller and faster than a mechanical relay, enabling smaller BMSs that more efficiently and safely manage battery cell charge. In another embodiment, a plurality of battery cells are connected to two rails, using four SSRs to control access to the battery cells. In one embodiment, a plurality of battery cells are grouped together and controlled as one module of a multi-module BMS. In one embodiment, each module has 10 battery cells in series. In one embodiment, the BMS controls 4 modules. In one embodiment, each module is controlled by control signals passing through logical gates. In another embodiment, each module is controlled by control signals passing through a programmed circuit.
    Type: Application
    Filed: December 12, 2003
    Publication date: June 16, 2005
    Inventors: Myoungho Lim, Mark Flaherty, Woo-chul Yi, Keith Griffin
  • Patent number: 6815223
    Abstract: A precursor for forming a thin film of layered superlattice material is applied to an integrated circuit substrate. The precursor coating is heated using rapid thermal processing (RTP) with a ramping rate of 100° C./second at a hold temperature in a range of from 500° C. to 900° C. for a cumulative heating time not exceeding 30 minutes, and preferably less than 5 minutes. In fabricating a ferroelectric memory cell, the coating is heated in oxygen using RTP, then a top electrode layer is formed, and then the substrate including the coating is heated using RTP in oxygen or in nonreactive gas after forming the top electrode layer. The thin film of layered superlattice material preferably comprises strontium bismuth tantalate or strontium bismuth tantalum niobate, and preferably has a thickness in a range of from 25 nm to 120 nm. The process of fabricating a thin film of layered superlattice material typically has a thermal budget value not exceeding 960,000° C.
    Type: Grant
    Filed: November 22, 2002
    Date of Patent: November 9, 2004
    Assignee: Symetrix Corporation
    Inventors: Jolanta Celinska, Vikram Joshi, Narayan Solayappan, Myoungho Lim, Larry D. McMillan, Carlos A. Paz de Araujo
  • Publication number: 20040101977
    Abstract: A precursor for forming a thin film of layered superlattice material is applied to an integrated circuit substrate. The precursor coating is heated using rapid thermal processing (RTP) with a ramping rate of 100° C./second at a hold temperature in a range of from 500° C. to 900° C. for a cumulative heating time not exceeding 30 minutes, and preferably less than 5 minutes. In fabricating a ferroelectric memory cell, the coating is heated in oxygen using RTP, then a top electrode layer is formed, and then the substrate including the coating is heated using RTP in oxygen or in nonreactive gas after forming the top electrode layer. The thin film of layered superlattice material preferably comprises strontium bismuth tantalate or strontium bismuth tantalum niobate, and preferably has a thickness in a range of from 25 nm to 120 nm. The process of fabricating a thin film of layered superlattice material typically has a thermal budget value not exceeding 960,000° C.
    Type: Application
    Filed: November 22, 2002
    Publication date: May 27, 2004
    Applicant: Symetrix Corporation
    Inventors: Jolanta Celinska, Vikram Joshi, Narayan Solayappan, Myoungho Lim, Larry D. McMillan, Carlos A. Paz de Araujo
  • Publication number: 20040047174
    Abstract: A ferroelectric memory 636 includes a group of memory cells (645, 12, 201, 301, 401, 501), each cell having a ferroelectric memory element (44, 218, etc.), a drive line (122, 322, 422, 522 etc.) on which a voltage for writing information to the group of memory cells is placed, a bit line (25, 49, 125, 325, 425, 525, etc.) on which information to be read out of the group of memory cells is placed, a preamplifier (20, 42, 120, 320, 420, etc.) between the memory cells and the bit line, a set switch (14, 114, 314, 414, 514, etc.) connected between the drive line and the memory cells, and a reset switch (16, 116, 316, 416, 516, etc.) connected to the memory cells in parallel with the preamplifier. The memory is read by placing a voltage less than the coercive voltage of the ferroelectric memory element across a memory element. Prior to reading, noise from the group of cells is discharged by grounding both electrodes of the ferroelectric memory element.
    Type: Application
    Filed: October 9, 2003
    Publication date: March 11, 2004
    Inventors: Zheng Chen, Vikram Joshi, Myoungho Lim, Carlos A. Paz de Araujo, Larry D. McMillan, Yoshihisa Kato, Tatsuo Otsuki, Yasuhiro Shimada
  • Patent number: 6441414
    Abstract: A ferroelectric non-volatile memory in which each memory cell consists of a single electronic element, a ferroelectric FET. The FET includes a source, drain, gate and substrate. The fact that the drain to source current, lds, is always negative if a substrate to drain bias, Vss, of 0.8 volts or more is applied, permits the creation of a read and write truth table. A gate voltage equal to one truth table logic value is applied via a column decoder and a substrate bias equal to another truth table logic value is applied via a row decoder to write to the memory a resultant lds logic state, which can be read whenever a voltage is placed across the source and drain.
    Type: Grant
    Filed: October 13, 1998
    Date of Patent: August 27, 2002
    Assignee: Symetrix Corporation
    Inventors: Myoungho Lim, Vikram Joshi, Jeffrey W. Bacon, Joseph D. Cuchiaro, Larry D. McMillan, Carlos A. Paz de Araujo
  • Patent number: 6437380
    Abstract: An integrated circuit device includes a thin film of bismuth-containing layered superlattice material having a thickness not exceeding 100 nm, a capping layer thin film of bismuth tantalate, and an electrode. The capping layer has a thickness in a range of from 3 nm to 30 nm and is deposited between the thin film of layered superlattice material and the electrode to increase dielectric breakdown voltage. Preferably the capping layer contains an excess amount of bismuth relative to the stoichiometrically balanced amount represented by the balanced stoichiometric formula BiTaO4. Preferably, the layered superlattice material is ferroelectric SBT or SBTN. Preferably, the integrated circuit device is a nonvolatile ferroelectric memory. Heating treatments for fabrication of the integrated circuit device containing the bismuth tantalate capping layerare conducted at temperatures not exceeding 700° C., preferably in a range of from 650° C. to 700° C.
    Type: Grant
    Filed: March 28, 2001
    Date of Patent: August 20, 2002
    Assignee: Symetrix Corporation
    Inventors: Myoungho Lim, Vikram Joshi, Narayan Solayappan, Larry D. McMillan, Carlos A. Paz de Araujo
  • Patent number: 6373743
    Abstract: A ferroelectric non-volatile memory comprising: a plurality of memory cells each containing a ferroelectric FET, each of said ferroelectric FETs having a source, a drain, a substrate, and a gate. The FETs are arranged in an array comprising a plurality of rows and a plurality of columns. There are a plurality of row select lines, each associated with one of the rows of said ferroelectric FETs, and a plurality of column select lines, each associated with one of the columns of ferroelectric FETs. Each of the sources is directly electrically connected to its associated row select line, and each of the drains is directly electrically connected to its associated column select line. The source and substrate of each FET are also directly electrically connected. A memory cell is read by connecting its row select line to ground, and its column select line to a small voltage. All the gates, and the row select lines of non-selected cells are open or connected to a high resistance source.
    Type: Grant
    Filed: August 30, 1999
    Date of Patent: April 16, 2002
    Assignee: Symetrix Corporation
    Inventors: Zheng Chen, Myoungho Lim, Vikram Joshi, Carlos A. Paz de Araujo, Larry D. McMillan
  • Patent number: 6370056
    Abstract: A ferroelectric non-volatile memory comprising: a plurality of memory cells, each containing an FeFET and a MOSFET, each of said FeFETs having a source, a drain, a substrate, and a gate, and each MOSFET having a pair of source/drains and a gate. The cells are arranged in an array comprising a plurality of rows and a plurality of columns. A gate line and a bit line are associated with each column, and a word line, a drain line, and a substrate line are associated with each row. One source/drain of each MOSFET is connected to its corresponding gate line; the other source/drain is connected to the gate of the FeFET in the cell. The gate of the MOSFET is connected to its corresponding word line which provides a write and erase enable signal. The drain of the FeFET is connected to its corresponding drain line, and the source of the FeFET is connected to its corresponding bit line. The substrate of each FeFET is connected to its corresponding substrate line.
    Type: Grant
    Filed: March 10, 2000
    Date of Patent: April 9, 2002
    Assignee: Symetrix Corporation
    Inventors: Zheng Chen, Vikram Joshi, Myoungho Lim, Carlos A. Paz de Araujo, Larry D. McMillan
  • Patent number: 6339238
    Abstract: A ferroelectric non-volatile memory in which each memory cell consists of a single electronic element, a ferroelectric FET. The FET includes a source, drain, gate and substrate. A cell is selected for writing or reading by application of bias voltages to the source, drain, gate or substrate. A gate voltage equal to one truth table logic value and a drain voltage equal to another truth table logic value are applied via a row decoder, and a substrate bias equal to a third truth table logic value is applied via a column decoder to write to the memory a resultant Ids logic state, which can be non-destructively read by placing a voltage across the source and drain.
    Type: Grant
    Filed: June 10, 1999
    Date of Patent: January 15, 2002
    Assignee: Symetrix Corporation
    Inventors: Myoungho Lim, Vikram Joshi, Joseph D. Cuchiaro, Larry D. McMillan, Carlos A. Paz de Araujo