Patents by Inventor Zhizheng Liu

Zhizheng Liu 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: 7553727
    Abstract: The present invention pertains to implementing a dual poly process in forming a transistor based memory device. The process allows a first polysilicon layer to be selectively doped subsequent to deposition of the second polysilicon layer. The doping increases the conductivity of the first polysilicon layer which can achieve a more robust charging protection for multi-bit core array and a more uniform distribution of charge.
    Type: Grant
    Filed: March 16, 2007
    Date of Patent: June 30, 2009
    Assignee: Spansion LLC
    Inventors: Ming-Sang Kwan, Bradley Marc Davis, Jean Yee-Mei Yang, Zhizheng Liu, Yi He
  • Publication number: 20090161462
    Abstract: A system and methodology that can minimize disturbance during an AC operation associated with a memory, such as, program, read and/or erase, is provided. The system pre-charges all or a desired subset of the bit lines in a memory array to a specified voltage, during an AC operation to facilitate reducing AC disturbances between neighboring cells. A pre-charge voltage can be applied to all bit lines in a block in the memory array, or to bit lines associated with a selected memory cell and neighbor memory cells adjacent to the selected memory cell in the block. The system ensures that source and drain voltage levels can be set to desired levels at the same or substantially the same time, while selecting a memory cell. This can facilitate minimizing AC disturbances in the selected memory cell during the AC operation.
    Type: Application
    Filed: December 21, 2007
    Publication date: June 25, 2009
    Applicant: SPANSION LLC
    Inventors: Sung-Yong Chung, Zhizheng Liu, Yugi Mizuguchi, Xuguang Alan Wang, Yi He, Ming Kwan, Darlene Hamilton, Sung-Chul Lee, Guowei Wang, Nancy Leong
  • Publication number: 20090154251
    Abstract: Methods and systems for accurately programming or erasing one or more memory cells on a selected wordline of a memory device are provided. In one embodiment, the memory device comprises a memory array, a threshold voltage measuring component configured to measure a threshold voltage of each memory cell on the selected wordline of the memory array, and an average threshold voltage determining component configured to determine an average threshold voltage result uniquely associated with the selected wordline, based on the measured threshold voltages. The memory device is configured to program one or more of the memory cells to a predefined program level relative to the determined average threshold voltage, or to erase memory cells of the selected wordline to the determined average threshold voltage. The method is particularly useful for multi-level flash memory cells to reduce charge loss while improving data reliability and Vt distributions of the programmed element states.
    Type: Application
    Filed: December 18, 2007
    Publication date: June 18, 2009
    Applicant: SPANSION LLC
    Inventors: Gwyn Robert Jones, Edward Franklin Runnion, Zhizheng Liu, Mark William Randolph
  • Publication number: 20090154246
    Abstract: Systems and methods that facilitate improved programming memory cells in a nonvolatile memory (e.g., flash memory) are presented. An optimized voltage component can facilitate supplying respective voltages to a source, drain, and gate associated with a memory cell during operations, such as programming operations. The optimized voltage component can facilitate supplying a predetermined source bitline voltage to a memory cell during programming of the cell to facilitate reducing leakage currents associated with the bitlines, which can improve programming of the memory cell, and to facilitate reducing the programming current, which can result in power efficient programming and improved programming speed.
    Type: Application
    Filed: December 13, 2007
    Publication date: June 18, 2009
    Applicant: SPANSION LLC
    Inventors: Zhizheng Liu, An Chen, Wei Zheng, Kuo-Tung Chang, Sung-Yong Chung, Gulzar Ahmed Kathawala, Ashot Melik-Martirosian
  • Publication number: 20090147589
    Abstract: A memory device comprising an optimization component that facilitates erasing memory cells in a substantially homogeneous electromagnetic field and methods that facilitate erasing memory cells in a substantially homogeneous electromagnetic field are presented. The optimization component facilitates selecting a subset of memory cells to be erased at the same time, such that a memory cell in the subset of memory cells has two neighbor memory cells adjacent thereto that are in the subset of memory, or one neighbor memory cell adjacent thereto when the memory cell is an end-row memory cell. The optimization component facilitates performing a Fowler-Nordheim channel erase to erase the subset of memory cells, and a predetermined voltage potential associated with an erase command is applied to each cell of the subset of memory cells to facilitate reducing fringing effect associated with the electromagnetic fields applied to the cells during the erase.
    Type: Application
    Filed: December 10, 2007
    Publication date: June 11, 2009
    Applicant: Spansion LLC
    Inventors: Gulzar Ahmed Kathawala, Wei Zheng, Zhizheng Liu, Sung-Yong Chung, Timothy Thurgate, Kuo-Tung Chang, Sheung-Hee Park, Gabrielle Wing Han Leung
  • Publication number: 20090135659
    Abstract: Providing for suppression of room temperature electronic drift in a flash memory cell is provided herein. For example, a soft program pulse can be applied to the flash memory cell immediately after an erase pulse. The soft program pulse can help to mitigate dipole effects caused by non-combined electrons and holes in the memory cell. Specifically, by utilizing a relatively low gate voltage, the soft program pulse can inject electrons into the flash memory cell proximate a distribution of uncombined holes associated with the erase pulse in order to facilitate rapid combination of such particles.
    Type: Application
    Filed: November 27, 2007
    Publication date: May 28, 2009
    Applicant: SPANSION LLC
    Inventors: Gwyn Robert Jones, Mark W. Randolph, John Darilek, Sean O'Mullan, Jacob Marcantel, Rick Anundson, Adam Shackleton, Xiaojian Chu, Abhijit Raghunathan, Asif Arfi, Gulzar Ahmed Kathawala, Zhizheng Liu, Sung-Chul Lee
  • Publication number: 20080279014
    Abstract: Erasing wordlines at the same time can cause undesirable results because some wordlines are affected by electromagnetic waves of other wordlines. However, other wordlines are not affected because they are next to contacts. Therefore, it can be beneficial to erase wordlines in a multi-phase sequence that allows for erasing wordlines without an impact from other wordlines.
    Type: Application
    Filed: May 7, 2007
    Publication date: November 13, 2008
    Applicant: SPANSION LLC
    Inventors: Xuguang Wang, Yi He, Zhizheng Liu, Sung-Yong Chung, Darlene G. Hamilton, Ashot Melik-Martirosian, Gulzar Kathawala, Ming Sang Kwan, Mark Randolph, Timothy Thurgate
  • Patent number: 7432688
    Abstract: The present invention provides a soft-transition controller for use with a synchronous converter having primary and secondary rectifiers. In one embodiment, the soft-transition controller includes a primary driver configured to provide a primary drive signal to the primary rectifier operating in a synchronous mode, while the secondary rectifier is operating in a diode mode, to provide an output voltage of the synchronous rectifier. Additionally, the soft-transition controller also includes a complementary driver coupled to the primary driver and configured to provide a soft-transition drive signal during a transition period, which transfers the secondary rectifier from the diode mode to a synchronous mode while maintaining the output voltage within a predetermined voltage range.
    Type: Grant
    Filed: February 17, 2006
    Date of Patent: October 7, 2008
    Assignee: Lineage Power Corporation
    Inventors: Zhizheng Liu, Lam D. Vu
  • Patent number: 7394702
    Abstract: A dual-bit memory device includes a first charge storage region spaced apart from a second charge storage region by an isolation region. Techniques for erasing a memory can be provided in which electrons can be injected into the charge storage regions to erase the charge storage regions. Other techniques for programming a memory can be provided in which holes can be injected into at least one of the charge storage regions to program the charge storage regions.
    Type: Grant
    Filed: April 5, 2006
    Date of Patent: July 1, 2008
    Assignee: Spansion LLC
    Inventors: Meng Ding, Zhizheng Liu, Wei Zheng
  • Publication number: 20080153274
    Abstract: A method of forming at least a portion of a dual bit memory core array upon a semiconductor substrate, the method comprising performing front end processing, performing a first bitline implant, or pocket implants, or both into the first bitline spacings to establish buried first bitlines within the substrate, depositing a layer of the spacer material over the charge trapping dielectric and the polysilicon layer features, forming a sidewall spacer adjacent to the charge trapping dielectric and the polysilicon layer features to define second bitline spacings between adjacent memory cells, performing a deep arsenic implant into the second bitline spacings to establish a second bitline within the structure that is deeper than the first bit line, removing the sidewall spacers and performing back end processing.
    Type: Application
    Filed: December 26, 2006
    Publication date: June 26, 2008
    Inventors: Timothy Thurgate, Yi He, Ming-Sang Kwan, Zhizheng Liu, Xuguang Wang
  • Publication number: 20080150006
    Abstract: The present invention pertains to implementing a dual poly process in forming a transistor based memory device. The process allows a first polysilicon layer to be selectively doped subsequent to deposition of the second polysilicon layer. The doping increases the conductivity of the first polysilicon layer which can achieve a more robust charging protection for multi-bit core array and a more uniform distribution of charge.
    Type: Application
    Filed: March 16, 2007
    Publication date: June 26, 2008
    Inventors: Ming-Sang Kwan, Bradley Marc Davis, Jean Yee-Mei Yang, Zhizheng Liu, Yi He
  • Publication number: 20080153223
    Abstract: The present invention pertains to a system method of forming at least a portion of a dual bit memory core array upon a semiconductor substrate, the method comprising forming adjacent first memory cell process assemblies; comprising a charge trapping dielectric, a first polysilicon layer and defining a first bitline opening there between, forming first polysilicon layer features over the charge trapping dielectric layer, depositing a layer of second spacer material over the charge trapping dielectric and the first polysilicon layer features, forming a sidewall spacer adjacent to the charge trapping dielectric and the first polysilicon layer features to define a second bitline opening between the adjacent memory cells, performing a bitline implant, or pocket implants, or both into the bitline opening to establish buried bitlines within the substrate having respective bitline widths that are narrower than the respective widths of the first bitline openings, removing the sidewall spacers, and performing back end
    Type: Application
    Filed: March 16, 2007
    Publication date: June 26, 2008
    Inventors: Zhizheng Liu, Shankar Sinha, Timothy Thurgate, Ming-Sang Kwan
  • Publication number: 20080153269
    Abstract: The present invention pertains to a system and method for implementing dummy tiles in forming a memory device. The system and method involves forming at least a portion of a memory core array upon a semiconductor substrate comprising, forming STI structures in the substrate, depositing an oxide layer over the substrate, forming a first polysilicon layer over the oxide layer, doping the first polysilicon layer, forming a second polysilicon layer over the first polysilicon layer, patterning at least one memory core, patterning at least one dummy tile and performing back end processing.
    Type: Application
    Filed: December 26, 2006
    Publication date: June 26, 2008
    Inventors: Cinti Chen, Yi He, Wenmei Li, Zhizheng Liu, Ming-Sang Kwan, Yu Sun, Jean Yee-Mei Yang
  • Publication number: 20080142889
    Abstract: A semiconductor device includes a substrate and a memory cell formed on the substrate. The memory cell includes a word line. The semiconductor device also includes a protection area formed in the substrate, a conductive structure configured to extend the word line to the protection area, and a contact configured to short the word line and the protection area.
    Type: Application
    Filed: December 18, 2006
    Publication date: June 19, 2008
    Applicant: SPANSION L.L.C.
    Inventors: Wei ZHENG, Jean YANG, Mark RANDOLPH, Ming KWAN, Yi HE, Zhizheng LIU, Meng DING
  • Publication number: 20080135902
    Abstract: One embodiment of the present invention relates to a memory cell. The memory cell comprises a substrate and a stacked gate structure disposed on the substrate, wherein the stacked gate structure comprises a charge trapping dielectric layer that is adapted to store at least one bit of data. The memory cell further includes a source and drain in the substrate, wherein the source and drain are disposed at opposite sides of the stacked gate structure. A barrier region is disposed substantially beneath the source or the drain and comprises an inert species. Other embodiments are also disclosed.
    Type: Application
    Filed: December 6, 2006
    Publication date: June 12, 2008
    Inventors: Shankar Sinha, Yi He, Zhizheng Liu, Ming-Sang Kwan
  • Publication number: 20080123384
    Abstract: A semiconductor device includes a core memory array and a periphery area. The core memory array area includes a group of memory cells. The periphery area includes a group of select transistors. The select transistors are formed at substantially the same pitch as the memory cells in the core memory array and with substantially the same channel length.
    Type: Application
    Filed: August 18, 2006
    Publication date: May 29, 2008
    Applicant: SPANSION LLC
    Inventors: Mark RANDOLPH, Zhizheng LIU, Ashot MELIK-MARTIROSIAN, Yi HE, Shankar SINHA
  • Publication number: 20070267686
    Abstract: A semiconductor device includes a substrate, a memory cell formed on the substrate, and a contact to the substrate. The contact is formed in an area away from the memory cell and functions to raise the potential of the substrate.
    Type: Application
    Filed: July 24, 2007
    Publication date: November 22, 2007
    Applicant: SPANSION LLC
    Inventors: Ashot MARTIROSIAN, Zhizheng Liu, Mark Randolph
  • Publication number: 20070247923
    Abstract: A dual-bit memory device includes a first charge storage region spaced apart from a second charge storage region by an isolation region. Techniques for erasing a memory can be provided in which electrons can be injected into the charge storage regions to erase the charge storage regions. Other techniques for programming a memory can be provided in which holes can be injected into at least one of the charge storage regions to program the charge storage regions.
    Type: Application
    Filed: April 5, 2006
    Publication date: October 25, 2007
    Inventors: Meng Ding, Zhizheng Liu, Wei Zheng
  • Patent number: 7285827
    Abstract: A device includes a memory device and an NPN or PNP diode coupled to a word-line of the memory device. The NPN or PNP diode reduces device damage and performance impairment that may result from device charging by drawing charges away from the memory device.
    Type: Grant
    Filed: August 2, 2005
    Date of Patent: October 23, 2007
    Assignee: Spansion LLC
    Inventors: Yi He, Zhizheng Liu, Meng Ding, Wei Zheng
  • Patent number: 7269067
    Abstract: A method of programming a memory cell in a non-volatile memory device includes applying a first voltage to a control gate associated with the memory cell and applying a second voltage to a drain region associated with the memory cell. The method also includes applying a positive bias to a source region associated with the memory cell and/or applying a negative bias to a substrate region associated with the memory cell.
    Type: Grant
    Filed: July 6, 2005
    Date of Patent: September 11, 2007
    Assignee: Spansion LLC
    Inventors: Shankar Sinha, Zhizheng Liu, Yi He