Patents by Inventor Gowrishankar L. Chindalore

Gowrishankar L. Chindalore 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).

  • Publication number: 20080043525
    Abstract: A memory device is disclosed. A reference device of the memory includes a trimmable current source and a fixed current source. Currents provided by each source are summed to provide a reference current to a sense amplifier. The sense amplifier senses the state of a bit cell by comparing a current from the bit cell, representative of a logic value, to the reference current. By basing the reference current on both a fixed and a trimmable current source, the reference device can be trimmed to compensate for process and operating characteristics of the device, while maintaining a minimum reference current in the event of a disturb mechanism that results in loss of the current provided by the trimmable current source.
    Type: Application
    Filed: May 17, 2006
    Publication date: February 21, 2008
    Applicant: Freescale Semiconductor, Inc.
    Inventors: Ronald J. Syzdek, Gowrishankar L. Chindalore
  • Patent number: 7317222
    Abstract: A memory cell is programmed by injecting charge into a charge storage layer of the memory cell. A desired programmed charge results in the charge storage layer over an edge portion of a channel region of the memory cell. An undesired programmed charge results in the charge storage layer over an inner portion of the channel region. Charge tunneling is used to substantially remove the undesired programmed charge in the charge storage layer. In one form the memory cell has a substrate having a channel region, a first dielectric layer over the substrate and a charge storage layer over the first dielectric layer. A second dielectric layer over the charge storage layer has a first portion that is thicker than a second portion to selectively control the charge tunneling.
    Type: Grant
    Filed: January 27, 2006
    Date of Patent: January 8, 2008
    Assignee: Freescale Semiconductor, Inc.
    Inventors: Craig T. Swift, Gowrishankar L. Chindalore
  • 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: 7259999
    Abstract: A method is provided which includes erasing a first plurality of non-volatile memory bit cells in a memory block comprising a third plurality of memory bit cells during an erase procedure, such that upon completion of the erase procedure, the first plurality of non-volatile memory bit cells are at an erased state. The method also includes programming a second plurality of non-volatile memory bit cells in the memory block during the erase procedure, such that the second plurality of non-volatile memory bit cells is a subset of the third plurality of non-volatile memory bit cells and upon completion of the erase procedure, the second plurality of non-volatile memory bit cells are at a programmed state.
    Type: Grant
    Filed: October 26, 2005
    Date of Patent: August 21, 2007
    Assignee: Freescale Semiconductor, Inc
    Inventors: Ronald J. Syzdek, Gowrishankar L. Chindalore, Paul A. Ingersoll, Peter J. Kuhn
  • 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: 7250340
    Abstract: A method of fabricating a semiconductor storage cell that includes first and second source/drain regions underlying first and second trenches defined in a semiconductor substrate. Sidewalls of the trenches are lined with a charge storage stack that includes a layer of discontinuous storage elements (DSEs), which are preferably silicon nanocrystals. Spacer control gates are located in the trenches adjacent to the charge storage stacks on the trench sidewalls. The trench depth exceeds the spacer height so that a gap exists between a top of the spacers and the top of the substrate. A continuous select gate layer overlies the first trench. The gap facilitates ballistic programming of the DSEs adjacent to the gap by accelerating electrons traveling substantially perpendicular to the trench sidewalls. The storage cell may employ hot carrier injection programming to program a portion of the DSEs proximal to the source/drain regions.
    Type: Grant
    Filed: July 25, 2005
    Date of Patent: July 31, 2007
    Assignee: Freescale Semiconductor, Inc.
    Inventors: Craig T. Swift, Gowrishankar L. Chindalore
  • 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: 7211487
    Abstract: A process for forming an electronic device can include forming a first trench within a substrate, wherein the trench includes a wall and a bottom and extends from a primary surface of the substrate. The process can also include forming discontinuous storage elements and forming a first gate electrode within the trench such that, a first discontinuous storage element of the discontinuous storage elements lies between the first gate electrode and the wall of the trench. The process can further include removing the discontinuous storage elements that overlie the primary surface of the substrate. The process can still further include forming a second gate electrode that overlies the first gate electrode and the primary surface of the substrate.
    Type: Grant
    Filed: July 25, 2005
    Date of Patent: May 1, 2007
    Assignee: Freescale Semiconductor, Inc.
    Inventors: Gowrishankar L. Chindalore, Paul A. Ingersoll, Criag T. Swift
  • Patent number: 7206214
    Abstract: A one time programmable (OTP) memory has two-bit cells for increasing density. Each cell has two select transistors and a programmable transistor in series between the two select transistors. The programmable transistor has two independent storage locations. One is between the gate and a first source/drain region and the second is between the gate and a second source/drain region. The storage locations are portions of the gate dielectric where the sources or drains overlap the gate and are independently programmed by selectively passing a programming current through them. The programming current is of sufficient magnitude and duration to permanently reduce the impedance by more than three orders of magnitude of the storage locations to be programmed. The programming current is limited in magnitude to avoid damage to other circuit elements and is preferably induced at least in part by applying a negative voltage to the gate of the programming transistor.
    Type: Grant
    Filed: August 5, 2005
    Date of Patent: April 17, 2007
    Assignee: Freescale Semiconductor, Inc.
    Inventors: Alexander B. Hoefler, Gowrishankar L. Chindalore
  • 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
  • Patent number: 7195983
    Abstract: A non-volatile memory (NVM) has a silicon germanium (SiGe) drain and a silicon carbon (SiC) source. The source being SiC provides for a stress on the channel that improves N channel mobility. The SiC also has a larger bandgap than the substrate, which is silicon. This results in it being more difficult to generate electron/hole pairs by impact ionization. Thus, it can be advantageous to use the SiC region for the drain during a read. The SiGe is used as the drain for programming and erase. The SiGe, having a smaller bandgap than the silicon substrate results in improved programming by generating electron/hole pairs by impact ionization and improved erasing by generating electron hole/pairs by band-to-band tunneling, both at lower voltage levels.
    Type: Grant
    Filed: August 31, 2004
    Date of Patent: March 27, 2007
    Assignee: Freescale Semiconductor, Inc.
    Inventors: Gowrishankar L. Chindalore, James David Burnett, Craig T. Swift, Ramachandran Muralidhar
  • Patent number: 7183161
    Abstract: A floating gate memory cell has a floating gate in which there are two floating gate layers. The top layer is etched to provide a contour in the top layer while leaving the lower layer unchanged. The control gate follows the contour of the floating gate to increase capacitance therebetween. The two layers of the floating gate can be polysilicon separated by a very thin etch stop layer. This etch stop layer is thick enough to provide an etch stop during a polysilicon etch but preferably thin enough to be electrically transparent. Electrons are able to easily move between the two layers. Thus the etch of the top layer does not extend into the lower layer but the first and second layer have the electrical effect for the purposes of a floating gate of being a continuous conductive layer.
    Type: Grant
    Filed: September 17, 2004
    Date of Patent: February 27, 2007
    Assignee: Freescale Semiconductor, Inc.
    Inventors: Gowrishankar L. Chindalore, 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: 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: 20070020857
    Abstract: A process for forming an electronic device can include forming a first trench within a substrate, wherein the trench includes a wall and a bottom and extends from a primary surface of the substrate. The process can also include forming discontinuous storage elements and forming a first gate electrode within the trench such that, a first discontinuous storage element of the discontinuous storage elements lies between the first gate electrode and the wall of the trench. The process can further include removing the discontinuous storage elements that overlie the primary surface of the substrate. The process can still further include forming a second gate electrode that overlies 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, Paul A. Ingersoll, 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: 7151302
    Abstract: A semiconductor device includes a memory array having a plurality of non-volatile memory cells. Each non-volatile memory cell of the plurality of non-volatile memory cells has a gate stack. The gate stack includes a control gate and a discrete charge storage layer such as a floating gate. A dummy stack ring is formed around the memory array. An insulating layer is formed over the memory array. The dummy stack ring has a composition and height substantially the same as a composition and height of the gate stack to insure that a CMP of the insulating layer is uniform across the memory array.
    Type: Grant
    Filed: June 24, 2005
    Date of Patent: December 19, 2006
    Assignee: Freescale Semiconductor, Inc.
    Inventor: Gowrishankar L. Chindalore