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: 7952938
    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: Grant
    Filed: May 4, 2010
    Date of Patent: May 31, 2011
    Assignee: 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
  • Patent number: 7944746
    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. Rapid combination in this manner reduces dipole effects caused by non-combined distributions of opposing charge within the memory cell, reducing room temperature program state drift.
    Type: Grant
    Filed: November 27, 2007
    Date of Patent: May 17, 2011
    Assignee: 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
  • Patent number: 7888218
    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: Grant
    Filed: March 16, 2007
    Date of Patent: February 15, 2011
    Assignee: Spansion LLC
    Inventors: Zhizheng Liu, Shankar Sinha, Timothy Thurgate, Ming-Sang Kwan
  • Publication number: 20100327773
    Abstract: An apparatus and method for dimming a light emitting diode (LED) driver. The apparatus includes a triode alternating current (TRIAC) dimmer and an LED driver receiving an input voltage from an output of the TRIAC dimmer so that the state of the LED driver is controlled by the TRIAC dimmer. The LED driver includes an active damping circuit configured for damping, upon detecting a rising edge of a bridge rectified input voltage, resonance caused by the TRIAC dimmer and the LED driver for a fixed period of time.
    Type: Application
    Filed: June 30, 2009
    Publication date: December 30, 2010
    Inventors: Wei Gu, Zhizheng Liu
  • Publication number: 20100314753
    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: August 20, 2010
    Publication date: December 16, 2010
    Applicant: SPANSION LLC
    Inventors: Ashot Melik MARTIROSIAN, Zhizheng LIU, Mark RANDOLPH
  • Patent number: 7804125
    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: Grant
    Filed: July 24, 2007
    Date of Patent: September 28, 2010
    Assignee: Spansion LLC
    Inventors: Ashot Melik Martirosian, Zhizheng Liu, Mark Randolph
  • Publication number: 20100240210
    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: May 28, 2010
    Publication date: September 23, 2010
    Applicant: SPANSION L.L.C.
    Inventors: Wei ZHENG, Jean YANG, Mark RANDOLPH, Ming KWAN, Yi HE, Zhizheng LIU, Meng DING
  • Publication number: 20100213535
    Abstract: Semiconductor devices having reduced parasitic current and methods of malting the semiconductor devices are provided. Further provided are memory devices having reduced adjacent wordline disturb. The memory devices contain wordlines formed over a semiconductor substrate, wherein at least one wordline space is formed between the wordlines. Adjacent wordline disturb is reduced by implanting one or more of indium, boron, and a combination of boron and indium in the surface of the at least one wordline space.
    Type: Application
    Filed: February 23, 2009
    Publication date: August 26, 2010
    Applicant: SPANSION LLC
    Inventors: Gulzar A. Kathawala, Zhizheng Liu, Kuo Tung Chang, Lei Xue
  • Publication number: 20100208527
    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: May 4, 2010
    Publication date: August 19, 2010
    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
  • Patent number: 7750407
    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: Grant
    Filed: December 18, 2006
    Date of Patent: July 6, 2010
    Assignee: Spansion LLC
    Inventors: Wei Zheng, Jean Yang, Mark Randolph, Ming Kwan, Yi He, Zhizheng Liu, Meng Ding
  • Patent number: 7746698
    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: Grant
    Filed: December 13, 2007
    Date of Patent: June 29, 2010
    Assignee: Spansion LLC
    Inventors: Zhizheng Liu, An Chen, Wei Zheng, Kuo-Tung Chang, Sung-Yong Chung, Gulzar Ahmed Kathawala, Ashot Melik-Martirosian
  • Patent number: 7746705
    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: Grant
    Filed: December 10, 2007
    Date of Patent: June 29, 2010
    Assignee: 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: 20100128521
    Abstract: Systems, methods, and devices that facilitate applying a predefined negative gate voltage to wordlines adjacent to a selected wordline associated with a memory cell selected during a read or verify operation to facilitate reducing adjacent wordline disturb are presented. A memory component can comprise an optimized operation component that can apply a predefined negative gate voltage to wordlines adjacent to a selected wordline associated with a memory cell selected for a read or verify operation, based at least in part on predefined operation criteria, to facilitate reducing adjacent wordline disturb in the selected memory cell to facilitate reducing a shift in the voltage threshold and maintain a desired operation window. The optimized operation component optionally can include an evaluator component that can facilitate determining whether a negative gate voltage applied to adjacent wordlines is to be adjusted to facilitate reducing adjacent wordline disturb below a predetermined threshold amount.
    Type: Application
    Filed: November 21, 2008
    Publication date: May 27, 2010
    Applicant: SPANSION LLC
    Inventors: Yuji Mizuguchi, Mark W. Randolph, Darlene Gay Hamilton, Yi He, Zhizheng Liu, Yanxia (Emma) Lin, Xianmin Yi, Gulzar Kathawala, Amol Ramesh Joshi, Kuo-Tung Chang, Edward Franklin Runnion, Sung-Chul Lee, Sung-Yong Chung, Yanxiang Liu, Yu Sun
  • Publication number: 20100103732
    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 30, 2009
    Publication date: April 29, 2010
    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
  • Patent number: 7679967
    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: Grant
    Filed: December 21, 2007
    Date of Patent: March 16, 2010
    Assignee: 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
  • Patent number: 7671405
    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: Grant
    Filed: December 26, 2006
    Date of Patent: March 2, 2010
    Assignee: Spansion LLC
    Inventors: Timothy Thurgate, Yi He, Ming-Sang Kwan, Zhizheng Liu, Xuguang Wang
  • Patent number: 7626869
    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: Grant
    Filed: May 7, 2007
    Date of Patent: December 1, 2009
    Assignee: 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: 7619932
    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: Grant
    Filed: December 18, 2007
    Date of Patent: November 17, 2009
    Assignee: Spansion LLC
    Inventors: Gwyn Robert Jones, Edward Franklin Runnion, Zhizheng Liu, Mark William Randolph
  • Patent number: 7573103
    Abstract: A device includes a memory device and an NPN or PNP diode coupled to a word-line of the memory device. The NPN diode includes a p-type substrate connected to ground, a well of n-type material formed in the p-type substrate in direct physical contact with the p-type substrate and electrically connected to the p-type substrate via a first metal line, a well of p-type material formed in the first well of n-type material, a first n-type region formed in the well of p-type material in direct physical contact with the well of p-type material and connected to the word line of the memory device, and a first p-type region formed in the well of n-type material in direct physical contact with the well of n-type material and electrically connected to the well of p-type material via a second metal line.
    Type: Grant
    Filed: September 14, 2007
    Date of Patent: August 11, 2009
    Assignee: Spansion LLC
    Inventors: Yi He, Zhizheng Liu, Meng Ding, Wei Zheng
  • Patent number: 7561457
    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: Grant
    Filed: August 18, 2006
    Date of Patent: July 14, 2009
    Assignee: Spansion LLC
    Inventors: Mark Randolph, Zhizheng Liu, Ashot Melik-Martirosian, Yi He, Shankar Sinha