Patents by Inventor Jeong Y. Choi

Jeong Y. Choi 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: 8587046
    Abstract: An embedded memory system includes an array of random access memory (RAM) cells, on the same substrate as an array of logic transistors. Each RAM cell includes an access transistor and a capacitor structure. The capacitor structure is fabricated by forming a metal-insulator-metal capacitor in a dielectric layer. The embedded RAM system includes fewer metal layers in the memory region than in the logic region.
    Type: Grant
    Filed: July 26, 2011
    Date of Patent: November 19, 2013
    Assignee: MoSys, Inc.
    Inventor: Jeong Y Choi
  • Patent number: 8460995
    Abstract: An embedded memory system includes an array of random access memory (RAM) cells, on the same substrate as an array of logic transistors. Each RAM cell includes an access transistor and a capacitor structure. The capacitor structure is fabricated by forming a metal-insulator-metal capacitor in a dielectric layer. The embedded RAM system includes fewer metal layers in the memory region than in the logic region.
    Type: Grant
    Filed: July 30, 2010
    Date of Patent: June 11, 2013
    Assignee: MoSys, Inc.
    Inventor: Jeong Y. Choi
  • Patent number: 8361863
    Abstract: A method of forming an embedded DRAM cell having multiple-thickness gate dielectrics. An oxidation-enhancing dopant is selectively implanted into a well region in an area that is exposed by a first mask. A thermal oxidation step simultaneously produces the field dielectric for two distinct devices each having a different oxide thickness. The method is applicable to quad-density DRAM cells using fewer oxidation steps. The method is also applicable to planar DRAM cells, and does not require increasing the number of masks during the fabrication of planar DRAM cells.
    Type: Grant
    Filed: November 13, 2008
    Date of Patent: January 29, 2013
    Assignee: MoSys, Inc.
    Inventor: Jeong Y. Choi
  • Patent number: 8238169
    Abstract: A method and apparatus for selectively restoring data in a non-volatile memory array based on failure type. Weakened data and erroneous data are identified by performing two readings of a specific memory section. Alternatively, an error correction code is used after a first reading of data to identify erroneous data. The manner in which data is restored will depend on whether the data changed because of an erase failure or a program failure. If only a program failure occurred then the data will be reprogrammed without an intervening erase step. If the data experienced an erase failure, then the data will be erased prior to being programmed with correct data.
    Type: Grant
    Filed: February 15, 2011
    Date of Patent: August 7, 2012
    Assignee: MoSys, Inc.
    Inventors: Jeong Y. Choi, Stephen Fung
  • Publication number: 20120056257
    Abstract: A method and system in which an embedded memory is fabricated in accordance with a conventional logic process includes one or more non-volatile memory cells, each having an access transistor and a capacitor, which share a common floating gate electrode. The coupling capacitor is provided with a dielectric layer having a thickness greater than the dielectric layer of the access transistor. Regions under the capacitor are implanted with a high dose implant to form an electrically shorted doped area in the channel region of the capacitor. The high dose implant improves the coupling ratio of the capacitor and enhances the uniformity of the capacitor's oxide layer.
    Type: Application
    Filed: September 2, 2010
    Publication date: March 8, 2012
    Applicant: MoSys, Inc.
    Inventor: Jeong Y. Choi
  • Publication number: 20120025285
    Abstract: An embedded memory system includes an array of random access memory (RAM) cells, on the same substrate as an array of logic transistors. Each RAM cell includes an access transistor and a capacitor structure. The capacitor structure is fabricated by forming a metal-insulator-metal capacitor in a dielectric layer.
    Type: Application
    Filed: July 26, 2011
    Publication date: February 2, 2012
    Applicant: MOSYS, INC.
    Inventor: Jeong Y. Choi
  • Publication number: 20120025347
    Abstract: An embedded memory system includes an array of dynamic random access memory (DRAM) cells, on the same substrate as an array of logic transistors. Each DRAM cell includes an access transistor and a capacitor structure. The capacitor structure is fabricated by forming a metal-insulator-metal capacitor in a dielectric layer.
    Type: Application
    Filed: July 30, 2010
    Publication date: February 2, 2012
    Applicant: MoSys, Inc.
    Inventor: Jeong Y. Choi
  • Publication number: 20110216596
    Abstract: A non-volatile memory cell having enhanced protection against mobile ions. The electric field within the memory cell is controlled in a manner that minimizes migration of mobile ions toward the floating gate. Each conductive layer in the memory cell is biased to reduce the flow of mobile ions toward the floating gate. The memory cell is preferably manufactured using a conventional logic process.
    Type: Application
    Filed: March 4, 2010
    Publication date: September 8, 2011
    Applicant: Mosys, Inc.
    Inventor: Jeong Y. Choi
  • Publication number: 20110141812
    Abstract: A method and apparatus for selectively restoring data in a non-volatile memory array based on failure type. Weakened data and erroneous data are identified by performing two readings of a specific memory section. Alternatively, an error correction code is used after a first reading of data to identify erroneous data. The manner in which data is restored will depend on whether the data changed because of an erase failure or a program failure. If only a program failure occurred then the data will be reprogrammed without an intervening erase step. If the data experienced an erase failure, then the data will be erased prior to being programmed with correct data.
    Type: Application
    Filed: February 15, 2011
    Publication date: June 16, 2011
    Applicant: MoSys, Inc.
    Inventors: Jeong Y. Choi, Stephen Fung
  • Patent number: 7929359
    Abstract: An embedded memory system that includes DRAM cells and logic transistors. The capacitor of the embedded memory responds to a positive bias voltage of ½ Vdd. The wordline driver of a p-channel access transistor applying the positive power supply voltage when the p-channel access FET is not being accessed and a voltage lower than the threshold voltage of the p-channel access FET is being accessed. For DRAM cells containing an n-channel access FET, the wordline driver applies either a negative voltage or the ground voltage to the n-channel access FET when the DRAM cell is not being accessed. A second voltage composed of Vdd and a boosted voltage is applied to the n-channel FET when the DRAM cell is being accessed.
    Type: Grant
    Filed: November 13, 2008
    Date of Patent: April 19, 2011
    Assignee: MoSys, Inc.
    Inventors: Jae Hong Jeong, Jeong Y. Choi
  • Patent number: 7894270
    Abstract: A method and apparatus for selectively restoring data in a non-volatile memory array based on failure type. Weakened data and erroneous data are identified by performing two readings of a specific memory section. Alternatively, an error correction code is used after a first reading of data to identify erroneous data. The manner in which data is restored will depend on whether the data changed because of an erase failure or a program failure. If only a program failure occurred then the data will be reprogrammed without an intervening erase step. If the data experienced an erase failure, then the data will be erased prior to being programmed with correct data.
    Type: Grant
    Filed: February 11, 2009
    Date of Patent: February 22, 2011
    Assignee: MoSys, Inc.
    Inventors: Jeong Y. Choi, Stephen Fung
  • Patent number: 7835890
    Abstract: The present invention is directed to a number of improvements in methods for reliability simulations in aged circuits whose operation has been degraded through hot-carrier or other effects. A plurality of different circuit stress times can be simulated within a single run. Different aging criteria may be used for different circuit blocks, circuit block types, devices, device models and device types. The user may specify the degradation of selected circuit blocks, circuit block types, devices, device models and device types independently of the simulation. Device degradation can be characterized in tables. Continuous degradation levels can be quantized. Techniques are also described for representing the aged device in the netlist as the fresh device augmented with a plurality of independent current sources connected between its terminals to mimic the effects of aging in the device. The use of device model cards with age parameters is also described.
    Type: Grant
    Filed: October 4, 2007
    Date of Patent: November 16, 2010
    Assignee: Cadence Design Systems, Inc.
    Inventors: Lifeng Wu, Zhihong Liu, Alvin I. Chen, Jeong Y. Choi, Bruce W. McGaughy
  • Publication number: 20100202203
    Abstract: A method and apparatus for selectively restoring data in a non-volatile memory array based on failure type. Weakened data and erroneous data are identified by performing two readings of a specific memory section. Alternatively, an error correction code is used after a first reading of data to identify erroneous data. The manner in which data is restored will depend on whether the data changed because of an erase failure or a program failure. If only a program failure occurred then the data will be reprogrammed without an intervening erase step. If the data experienced an erase failure, then the data will be erased prior to being programmed with correct data.
    Type: Application
    Filed: February 11, 2009
    Publication date: August 12, 2010
    Applicant: Mosys, Inc.
    Inventors: Jeong Y. Choi, Stephen Fung
  • Publication number: 20100140680
    Abstract: A process flow for creating a non-volatile memory cell, the process flow including the steps of forming a doped well in a semiconducting portion of a substrate, forming a gate dielectric layer on top of the substrate, depositing a first polysilicon layer on top of the gate dielectric layer, patterning and etching the first polysilicon layer, selectively oxidizing the first polysilicon layer, implanting lightly-doped source/drain regions into the well, forming sidewall spacers adjacent the first polysilicon layer, implanting source/drain regions into the well, thereby forming a channel area, depositing a dielectric layer on top of the first polysilicon layer, depositing a second polysilicon layer on top of the dielectric layer, forming a masking layer on the second polysilicon layer, and etching both the second polysilicon layer and the dielectric layer using the masking layer.
    Type: Application
    Filed: December 9, 2008
    Publication date: June 10, 2010
    Applicant: MoSys, Inc.
    Inventors: Jeong Y. Choi, Kameswara K. Rao
  • Publication number: 20100118596
    Abstract: An embedded memory system that includes DRAM cells and logic transistors. The capacitor of the embedded memory responds to a positive bias voltage of ½ Vdd. The wordline driver of a p-channel access transistor applying the positive power supply voltage when the p-channel access FET is not being accessed and a voltage lower than the threshold voltage of the p-channel access FET is being accessed. For DRAM cells containing an n-channel access FET, the wordline driver applies either a negative voltage or the ground voltage to the n-channel access FET when the DRAM cell is not being accessed. A second voltage composed of Vdd and a boosted voltage is applied to the n-channel FET when the DRAM cell is being accessed.
    Type: Application
    Filed: November 13, 2008
    Publication date: May 13, 2010
    Applicant: Mosys, Inc
    Inventors: Jae Hong Jeong, Jeong Y. Choi
  • Publication number: 20100120213
    Abstract: A method of forming an embedded DRAM cell having multiple-thickness gate dielectrics. An oxidation-enhancing dopant is selectively implanted into a well region in an area that is exposed by a first mask. A thermal oxidation step simultaneously produces the field dielectric for two distinct devices each having a different oxide thickness. The method is applicable to quad-density DRAM cells using fewer oxidation steps. The method is also applicable to planar DRAM cells, and does not require increasing the number of masks during the fabrication of planar DRAM cells.
    Type: Application
    Filed: November 13, 2008
    Publication date: May 13, 2010
    Applicant: Mosys, Inc.
    Inventor: Jeong Y. Choi
  • Publication number: 20090299716
    Abstract: The present invention is directed to a number of improvements in methods for hot-carrier device degradation modeling and extraction. Several improvements are presented for the improvement of building device degradation models, including allowing the user to select a device parameter used to build the device degradation model independent of the device parameter selected. The user can also select the functional relation between stress time and degradation level. To further improve accuracy, multiple acceleration parameters can be used to account for different regions of the degradation process. Analytical functions may be used to represent aged device model parameters, either directly or by fitting measured device parameters versus device age values, allowing devices with different age values to share the same device model. The concept of binning is extended to include device degradation. In addition to a binning based on device width and length, age is added.
    Type: Application
    Filed: June 17, 2009
    Publication date: December 3, 2009
    Inventors: Zhihong Liu, Lifeng Wu, Jeong Y. Choi, Ping Chen, Alvin I. Chen, Gang Zhang
  • Patent number: 7567891
    Abstract: The present invention is directed to a number of improvements in methods for hot-carrier device degradation modeling and extraction. Several improvements are presented for the improvement of building device degradation models, including allowing the user to select a device parameter used to build the device degradation model independent of the device parameter selected. The user can also select the functional relation between stress time and degradation level. To further improve accuracy, multiple acceleration parameters can be used to account for different regions of the degradation process. Analytical functions may be used to represent aged device model parameters, either directly or by fitting measured device parameters versus device age values, allowing devices with different age values to share the same device model. The concept of binning is extended to include device degradation. In addition to a binning based on device width and length, age is added.
    Type: Grant
    Filed: September 27, 2001
    Date of Patent: July 28, 2009
    Assignee: Cadence Design Systems, Inc.
    Inventors: Zhihong Liu, Lifeng Wu, Jeong Y. Choi, Ping Chen, Alvin I. Chen, Gang Zhang
  • Patent number: 7292968
    Abstract: The present invention is directed to a number of improvements in methods for reliability simulations in aged circuits whose operation has been degraded through hot-carrier or other effects. A plurality of different circuit stress times can be simulated within a single run. Different aging criteria may be used for different circuit blocks, circuit block types, devices, device models and device types. The user may specify the degradation of selected circuit blocks, circuit block types, devices, device models and device types independently of the simulation. Device degradation can be characterized in tables. Continuous degradation levels can be quantized. Techniques are also described for representing the aged device in the netlist as the fresh device augmented with a plurality of independent current sources connected between its terminals to mimic the effects of aging in the device. The use of device model cards with age parameters is also described.
    Type: Grant
    Filed: April 11, 2001
    Date of Patent: November 6, 2007
    Assignee: Cadence Design Systems, Inc.
    Inventors: Lifeng Wu, Zhihong Liu, Alvin I. Chen, Jeong Y. Choi, Bruce W. McGaughy
  • Patent number: 7219045
    Abstract: The present invention is directed to methods for reliability simulations in aged circuits whose operation has been degraded through hot-carrier or other effects by allowing design rules on degradation to be included in the netlist. Once the hot-carrier circuit simulation is launched, the rules are checked and the reliability design rule violations are reported. The process can be performed on either the layout or schematic window. The design rule criteria can be any device parameter and can be expressed in absolute or relative terms. The criteria can be based on device type, model card name, instance geometry, or temperature. Additionally, values can be set prior to beginning the simulation.
    Type: Grant
    Filed: September 27, 2001
    Date of Patent: May 15, 2007
    Assignee: Cadence Design Systems, Inc.
    Inventors: Lifeng Wu, Jeong Y. Choi, Alvin I. Chen, Jingkun Fang