Patents by Inventor Cheong M. Hong

Cheong M. Hong 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: 7557042
    Abstract: Floating gates are formed in two separate polysilicon depositions steps resulting in distinct portions. The first formed portions are between isolation regions. A thick insulator is formed over the isolation regions and floating gate portions. The thick insulator is patterned to leave fences over the isolation regions. A thinning process, an isotropic etch in this example, is applied to these fences to make them thinner. Polysilicon sidewall spacers are formed on the sides of these fences. These sidewall spacers become the second portion of the floating gate. These second portions have the desired shape for significantly increasing the capacitance to the subsequently formed control gates, thereby reducing the gate voltage required for programming and erasing made by a relatively robust process.
    Type: Grant
    Filed: June 28, 2004
    Date of Patent: July 7, 2009
    Assignee: Freescale Semiconductor, Inc.
    Inventors: Chi Nan Brian Li, Cheong M. Hong, Rana P. Singh
  • Patent number: 7550348
    Abstract: A storage device structure (10) has two bits of storage per control gate (34) and uses source side injection (SSI) to provide lower programming current. A control gate (34) overlies a drain electrode formed by a doped region (22) that is positioned in a semiconductor substrate (12). Two select gates (49 and 50) are implemented with conductive sidewall spacers adjacent to and lateral to the control gate (34). A source doped region (60) is positioned in the semiconductor substrate (12) adjacent to one of the select gates for providing a source of electrons to be injected into a storage layer (42) underlying the control gate. Lower programming results from the SSI method of programming and a compact memory cell size exists.
    Type: Grant
    Filed: September 28, 2006
    Date of Patent: June 23, 2009
    Assignee: Freescale Semiconductor, Inc.
    Inventors: Cheong M. Hong, Gowrishankar L. Chindalore
  • Patent number: 7521317
    Abstract: A method for forming a semiconductor device includes providing a semiconductor substrate comprising silicon, forming a layer of dielectric on the surface of the semiconductor substrate, forming a gate electrode comprising silicon over the layer of dielectric, recessing the layer of dielectric under the gate electrode, filling the recess with a discrete charge storage material, oxidizing a portion of the gate electrode, and oxidizing a portion of the semiconductor substrate.
    Type: Grant
    Filed: March 15, 2006
    Date of Patent: April 21, 2009
    Assignee: Freescale Semiconductor, Inc.
    Inventors: Chi Nan Brian Li, Ko-Min Chang, Cheong M. Hong
  • Patent number: 7471560
    Abstract: An electronic circuit can include a first memory cell and a second memory cell. In one embodiment, source/drain regions of the first and second memory cells can be electrically connected to each other. The source/drain regions may electrically float regardless of direction in which carriers flow through channel regions of the memory cells. In another embodiment, the first memory cell can be electrically connected to a first gate line, and the second memory cell can be electrically connected to a greater number of gate lines as compared to the first memory cell. In another aspect, the first and second memory cells are connected to the same bit line. Such bit line can electrically float when programming or reading the first memory cell or the second memory cell or any combination thereof.
    Type: Grant
    Filed: August 6, 2007
    Date of Patent: December 30, 2008
    Assignee: Freescale Semiconductor, Inc.
    Inventors: Jane A. Yater, Gowrishankar L. Chindalore, Cheong M. Hong
  • Patent number: 7459744
    Abstract: A programmable storage device includes a first diffusion region underlying a portion of a first trench defined in a semiconductor substrate and a second diffusion region occupying an upper portion of the substrate adjacent to the first trench. The device includes a charge storage stack lining sidewalls and a portion of a floor of the first trench. The charge storage stack includes a layer of discontinuous storage elements (DSEs). Electrically conductive spacers formed on opposing sidewalls of the first trench adjacent to respective charge storage stacks serve as control gates for the device. The DSEs may be silicon, polysilicon, metal, silicon nitride, or metal nitride nanocrystals or nanoclusters. The storage stack includes a top dielectric of CVD silicon oxide overlying the nanocrystals overlying a bottom dielectric of thermally formed silicon dioxide. The device includes first and second injection regions in the layer of DSEs proximal to the first and second diffusion regions.
    Type: Grant
    Filed: September 22, 2006
    Date of Patent: December 2, 2008
    Assignee: Freescale Semiconductor, Inc.
    Inventors: Cheong M. Hong, Chi-Nan Li
  • Patent number: 7378314
    Abstract: A storage device has a two bit cell in which the select electrode is nearest the channel between two storage layers. Individual control electrodes are over individual storage layers. Adjacent cells are separated by a doped region that is shared between the adjacent cells. The doped region is formed by an implant in which the select gates of adjacent cells are used as a mask. This structure provides for reduced area while retaining the ability to perform programming by source side injection.
    Type: Grant
    Filed: June 29, 2005
    Date of Patent: May 27, 2008
    Assignee: Freescale Semiconductor, Inc.
    Inventors: Cheong M. Hong, Gowrishankar L. Chindalore
  • Patent number: 7361551
    Abstract: A method for forming a portion of a semiconductor device includes: patterning gate stack layers overlying a substrate into a gate stack; implanting dopant ions to form shallow source/drain extension implant regions in the substrate adjacent to the gate stack; oxidizing the gate stack at first oxidation conditions to form an oxidation layer on sidewalls of the gate stack; and oxidizing the gate stack at second oxidation conditions to form further oxidation of the oxidation layer on sidewalls of the gate stack. The second oxidation conditions are different from the first oxidation conditions.
    Type: Grant
    Filed: February 16, 2006
    Date of Patent: April 22, 2008
    Assignee: Freescale Semiconductor, Inc.
    Inventors: Chi-Nan B. Li, Cheong M. Hong
  • Patent number: 7314798
    Abstract: A method of making an array of storage cells includes a first source/drain region underlying a first trench defined in a semiconductor substrate and a second source/drain region underlying a second trench in the substrate. A charge storage stack lines each of the trenches where the charge storage stack includes a layer of discontinuous storage elements (DSEs). A control gate overlies the first trench. The control gate may run perpendicular to the trenches and traverse the first and second trenches. In another implementation, the control gate runs parallel with the trenches. The storage cell may include one or more diffusion regions occupying an upper surface of the substrate between the first and second trenches. The diffusion region may reside between first and second control gates that are parallel to the trenches. Alternatively, a pair of diffusion regions may occur on either side of a control gate that is perpendicular to the trenches.
    Type: Grant
    Filed: July 25, 2005
    Date of Patent: January 1, 2008
    Assignee: Freescale Semiconductor, Inc.
    Inventors: Gowrishankar L. Chindalore, Cheong M. Hong, Craig T. Swift
  • Patent number: 7285819
    Abstract: An array of storage cells include a first source/drain region underlying a first trench defined in a semiconductor substrate and a second source/drain region underlying a second trench in the substrate. A charge storage stack lines each of the trenches where the charge storage stack includes a layer of discontinuous storage elements (DSEs). A control gate overlies the first trench. The control gate may run perpendicular to the trenches and traverse the first and second trenches. In another implementation, the control gate runs parallel with the trenches. The storage cell may include one or more diffusion regions occupying an upper surface of the substrate between the first and second trenches. The diffusion region may reside between first and second control gates that are parallel to the trenches. Alternatively, a pair of diffusion regions may occur on either side of a control gate that is perpendicular to the trenches.
    Type: Grant
    Filed: July 25, 2005
    Date of Patent: October 23, 2007
    Assignee: Freescale Semiconductor, Inc.
    Inventors: Gowrishankar L. Chindalore, Cheong M. Hong, Craig T. Swift
  • Patent number: 7262997
    Abstract: An electronic circuit can include a first memory cell and a second memory cell. In one embodiment, source/drain regions of the first and second memory cells can be electrically connected to each other. The source/drain regions may electrically float regardless of direction in which carriers flow through channel regions of the memory cells. In another embodiment, the first memory cell can be electrically connected to a first gate line, and the second memory cell can be electrically connected to a greater number of gate lines as compared to the first memory cell. In another aspect, the first and second memory cells are connected to the same bit line. Such bit line can electrically float when programming or reading the first memory cell or the second memory cell or any combination thereof.
    Type: Grant
    Filed: July 25, 2005
    Date of Patent: August 28, 2007
    Assignee: Freescale Semiconductor, Inc.
    Inventors: Jane A. Yater, Gowrishankar L. Chindalore, Cheong M. Hong
  • Patent number: 7256454
    Abstract: An electronic device can include discontinuous storage elements that lie within a trench. In one embodiment, the electronic device can include a substrate that includes a trench extending into a semiconductor material. The trench can include a ledge and a bottom, wherein the bottom lies at a depth deeper than the ledge. The electronic device can include discontinuous storage elements, wherein a trench portion of the discontinuous storage elements lies within the trench. Gate electrodes may lie adjacent to walls of the trench. In a particular embodiment, a portion of a channel region within a memory cell may not be covered by a gate electrode. In another embodiment, a doped region may underlie the ledge and allow for memory cells to be formed at different elevations within the trench. In other embodiment, a process can be used to form the electronic device.
    Type: Grant
    Filed: July 25, 2005
    Date of Patent: August 14, 2007
    Assignee: Freescale Semiconductor, Inc
    Inventors: Jane A. Yater, Gowrishankar L. Chindalore, Cheong M. Hong
  • Patent number: 7235823
    Abstract: A storage device structure (10) has two bits of storage per control gate (34) and uses source side injection (SSI) to provide lower programming current. A control gate (34) overlies a drain electrode formed by a doped region (22) that is positioned in a semiconductor substrate (12). Two select gates (49 and 50) are implemented with conductive sidewall spacers adjacent to and lateral to the control gate (34). A source doped region (60) is positioned in the semiconductor substrate (12) adjacent to one of the select gates for providing a source of electrons to be injected into a storage layer (42) underlying the control gate. Lower programming results from the SSI method of programming and a compact memory cell size exists.
    Type: Grant
    Filed: September 28, 2006
    Date of Patent: June 26, 2007
    Assignee: Freescale Semiconductor, Inc.
    Inventors: Cheong M. Hong, Gowrishankar L. Chindalore
  • Patent number: 7226840
    Abstract: A process for forming an electronic device can include forming a first set of discontinuous storage elements over a primary surface of a substrate and forming a trench within the substrate. The process can also include forming a second set of discontinuous storage elements within the trench. The process can further include forming a first gate electrode within the trench, wherein a discontinuous storage element lies between the first gate electrode and a wall of the trench. The process can still further include removing a part of the second set of discontinuous storage elements and forming a second gate electrode over the first gate electrode. After forming the second gate electrode, substantially none of the second set of discontinuous storage elements lies along the wall of the trench at an elevation between an upper surface of the first gate electrode and the primary surface of the substrate.
    Type: Grant
    Filed: July 25, 2005
    Date of Patent: June 5, 2007
    Assignee: Freescale Semiconductor, Inc.
    Inventors: Gowrishankar L. Chindalore, Cheong M. Hong, Craig T. Swift
  • Patent number: 7205608
    Abstract: An electronic device can include a substrate having a trench that includes a wall and a bottom. The electronic device can also include a first set of discontinuous storage elements that overlie a primary surface of the substrate and a second set of discontinuous storage elements that lie within the trench. The electronic device can also include a first gate electrode, wherein substantially none of the discontinuous storage elements lies along the wall of the trench at an elevation between and upper surface of the first gate electrode and the primary surface of the substrate. The electronic device can also include a second gate electrode overlying the first gate electrode and the primary surface. In another embodiment, a conductive line can be electrically connected to one or more rows or columns of memory cells, and another conductive line can be more rows or more columns of memory cells.
    Type: Grant
    Filed: July 25, 2005
    Date of Patent: April 17, 2007
    Assignee: Freescale Semiconductor, Inc.
    Inventors: Gowrishankar L. Chindalore, Cheong M. Hong, Craig T. Swift
  • Publication number: 20070018240
    Abstract: An electronic device can include a substrate having a trench that includes a wall and a bottom. The electronic device can also include a first set of discontinuous storage elements that overlie a primary surface of the substrate and a second set of discontinuous storage elements that lie within the trench. The electronic device can also include a first gate electrode, wherein substantially none of the discontinuous storage elements lies along the wall of the trench at an elevation between and upper surface of the first gate electrode and the primary surface of the substrate. The electronic device can also include a second gate electrode overlying the first gate electrode and the primary surface. In another embodiment, a conductive line can be electrically connected to one or more rows or columns of memory cells, and another conductive line can be more rows or more columns of memory cells.
    Type: Application
    Filed: July 25, 2005
    Publication date: January 25, 2007
    Applicant: Freescale Semiconductor, Inc.
    Inventors: Gowrishankar L. Chindalore, Cheong M. Hong, Craig T. Swift
  • Publication number: 20070020820
    Abstract: A process for forming an electronic device can include forming a first set of discontinuous storage elements over a primary surface of a substrate and forming a trench within the substrate. The process can also include forming a second set of discontinuous storage elements within the trench. The process can further include forming a first gate electrode within the trench, wherein a discontinuous storage element lies between the first gate electrode and a wall of the trench. The process can still further include removing a part of the second set of discontinuous storage elements and forming a second gate electrode over the first gate electrode. After forming the second gate electrode, substantially none of the second set of discontinuous storage elements lies along the wall of the trench at an elevation between an upper surface of the first gate electrode and the primary surface of the substrate.
    Type: Application
    Filed: July 25, 2005
    Publication date: January 25, 2007
    Applicant: Freescale Semiconductor, Inc.
    Inventors: Gowrishankar L. Chindalore, Cheong M. Hong, Craig T. Swift
  • Publication number: 20070001218
    Abstract: A storage device has a two bit cell in which the select electrode is nearest the channel between two storage layers. Individual control electrodes are over individual storage layers. Adjacent cells are separated by a doped region that is shared between the adjacent cells. The doped region is formed by an implant in which the select gates of adjacent cells are used as a mask. This structure provides for reduced area while retaining the ability to perform programming by source side injection.
    Type: Application
    Filed: June 29, 2005
    Publication date: January 4, 2007
    Inventors: Cheong M. Hong, Gowrishankar L. Chindalore
  • Patent number: 7132329
    Abstract: A storage device structure (10) has two bits of storage per control gate (34) and uses source side injection (SSI) to provide lower programming current. A control gate (34) overlies a drain electrode formed by a doped region (22) that is positioned in a semiconductor substrate (12). Two select gates (49 and 50) are implemented with conductive sidewall spacers adjacent to and lateral to the control gate (34). A source doped region (60) is positioned in the semiconductor substrate (12) adjacent to one of the select gates for providing a source of electrons to be injected into a storage layer (42) underlying the control gate. Lower programming results from the SSI method of programming and a compact memory cell size exists.
    Type: Grant
    Filed: June 29, 2005
    Date of Patent: November 7, 2006
    Assignee: Freescale Semiconductor, Inc.
    Inventors: Cheong M. Hong, Gowrishankar L. Chindalore