Patents by Inventor Yanli Zhang

Yanli Zhang 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: 9379132
    Abstract: Methods of making monolithic three-dimensional memory devices include performing a first etch to form a memory opening and a second etch using a different etching process to remove a damaged portion of the semiconductor substrate from the bottom of the memory opening. A single crystal semiconductor material is formed over the substrate in the memory opening using an epitaxial growth process. Additional embodiments include improving the quality of the interface between the semiconductor channel material and the underlying semiconductor layers in the memory opening which may be damaged by the bottom opening etch, including forming single crystal semiconductor channel material by epitaxial growth from the bottom surface of the memory opening and/or oxidizing surfaces exposed to the bottom opening etch and removing the oxidized surfaces prior to forming the channel material. Monolithic three-dimensional memory devices formed by the embodiment methods are also disclosed.
    Type: Grant
    Filed: October 24, 2014
    Date of Patent: June 28, 2016
    Assignee: SANDISK TECHNOLOGIES INC.
    Inventors: Sateesh Koka, Raghuveer S. Makala, Yanli Zhang, Senaka Kanakamedala, Rahul Sharangpani, Yao-Sheng Lee, George Matamis
  • Publication number: 20160163389
    Abstract: A memory stack structure includes a cavity including a back gate electrode, a back gate dielectric, a semiconductor channel, and at least one charge storage element. In one embodiment, a line trench can be filled with a memory film layer, and a plurality of semiconductor channels can straddle the line trench. The back gate electrode can extend along the lengthwise direction of the line trench. In another embodiment, an isolated memory opening overlying a patterned conductive layer can be filled with a memory film, and the back gate electrode can be formed within a semiconductor channel and on the patterned conductive layer. A dielectric cap portion electrically isolates the back gate electrode from a drain region. The back gate electrode can be employed to bias the semiconductor channel, and to enable sensing of multinary bits corresponding to different amounts of electrical charges stored in a memory cell.
    Type: Application
    Filed: December 9, 2014
    Publication date: June 9, 2016
    Inventors: Yanli ZHANG, Johann ALSMEIER, Yinda DONG, Akira MATSUDAIRA
  • Publication number: 20160163729
    Abstract: A memory stack structure includes a cavity including a back gate electrode, a back gate dielectric, a semiconductor channel, and at least one charge storage element. In one embodiment, a line trench can be filled with a memory film layer, and a plurality of semiconductor channels can straddle the line trench. The back gate electrode can extend along the lengthwise direction of the line trench. In another embodiment, an isolated memory opening overlying a patterned conductive layer can be filled with a memory film, and the back gate electrode can be formed within a semiconductor channel and on the patterned conductive layer. A dielectric cap portion electrically isolates the back gate electrode from a drain region. The back gate electrode can be employed to bias the semiconductor channel, and to enable sensing of multinary bits corresponding to different amounts of electrical charges stored in a memory cell.
    Type: Application
    Filed: December 9, 2014
    Publication date: June 9, 2016
    Inventors: Yanli ZHANG, Johann ALSMEIER, Yingda DONG, Akira MATSUDAIRA
  • Patent number: 9355727
    Abstract: A memory stack structure includes a cavity including a back gate electrode, a back gate dielectric, a semiconductor channel, and at least one charge storage element. In one embodiment, a line trench can be filled with a memory film layer, and a plurality of semiconductor channels can straddle the line trench. The back gate electrode can extend along the lengthwise direction of the line trench. In another embodiment, an isolated memory opening overlying a patterned conductive layer can be filled with a memory film, and the back gate electrode can be formed within a semiconductor channel and on the patterned conductive layer. A dielectric cap portion electrically isolates the back gate electrode from a drain region. The back gate electrode can be employed to bias the semiconductor channel, and to enable sensing of multinary bits corresponding to different amounts of electrical charges stored in a memory cell.
    Type: Grant
    Filed: December 9, 2014
    Date of Patent: May 31, 2016
    Assignee: SANDISK TECHNOLOGIES INC.
    Inventors: Yanli Zhang, Johann Alsmeier, Yinda Dong, Akira Matsudaira
  • Patent number: 9356014
    Abstract: Semiconductor structures and methods of manufacture are disclosed herein. Specifically, disclosed herein are methods of manufacturing a high-voltage metal-oxide-semiconductor field-effect transistor and respective structures. A method includes forming a field-effect transistor (FET) on a substrate in a FET region, forming a high-voltage FET (HVFET) on a dielectric stack over a over lightly-doped diffusion (LDD) drain in a HVFET region, and forming an NPN on the substrate in an NPN region.
    Type: Grant
    Filed: October 24, 2014
    Date of Patent: May 31, 2016
    Assignee: GLOBALFOUNDRIES INC.
    Inventors: William F. Clark, Jr., Qizhi Liu, John J. Pekarik, Yun Shi, Yanli Zhang
  • Publication number: 20160125788
    Abstract: Techniques related to image dithering are described herein. The techniques include receiving an image to be displayed at a display device and entering a content adaptive backlight control mode. The image is dithered during the content adaptive backlight control mode. The dithering is disabled during a panel self-refresh mode.
    Type: Application
    Filed: November 4, 2014
    Publication date: May 5, 2016
    Inventors: Yanli Zhang, Seh Kwa
  • Patent number: 9330763
    Abstract: Methods for performing memory operations on a memory array that includes inverted NAND strings are described. The memory operations may include erase operations, read operations, programming operations, program verify operations, and erase verify operations. An inverted NAND string may include a string of inverted floating gate transistors or a string of inverted charge trap transistors. In one embodiment, an inverted floating gate transistor may include a tunneling layer between a floating gate of the inverted floating gate transistor and a control gate of the inverted floating gate transistor. The arrangement of the tunneling layer between the floating gate and the control gate allows electrons to be added to or removed from the floating gate via F-N tunneling between the floating gate and the control gate. The inverted NAND string may be formed above a substrate and oriented such that the inverted NAND string is orthogonal to the substrate.
    Type: Grant
    Filed: December 1, 2014
    Date of Patent: May 3, 2016
    Assignee: SANDISK TECHNOLOGIES INC.
    Inventors: Yanli Zhang, George Samachisa, Johann Alsmeier, Jian Chen
  • Patent number: 9331090
    Abstract: A NAND device has at least a 3×3 array of vertical NAND strings in which the control gate electrodes are continuous in the array and do not have an air gap or a dielectric filled trench in the array. The NAND device is formed by first forming a lower select gate level having separated lower select gates, then forming plural memory device levels containing a plurality of NAND string portions, and then forming an upper select gate level over the memory device levels having separated upper select gates.
    Type: Grant
    Filed: October 17, 2014
    Date of Patent: May 3, 2016
    Assignee: SANDISK TECHNOLOGIES INC.
    Inventors: Johann Alsmeier, Raghuveer S. Makala, Xiying Costa, Yanli Zhang
  • Publication number: 20160118397
    Abstract: Methods of making monolithic three-dimensional memory devices include performing a first etch to form a memory opening and a second etch using a different etching process to remove a damaged portion of the semiconductor substrate from the bottom of the memory opening. A single crystal semiconductor material is formed over the substrate in the memory opening using an epitaxial growth process. Additional embodiments include improving the quality of the interface between the semiconductor channel material and the underlying semiconductor layers in the memory opening which may be damaged by the bottom opening etch, including forming single crystal semiconductor channel material by epitaxial growth from the bottom surface of the memory opening and/or oxidizing surfaces exposed to the bottom opening etch and removing the oxidized surfaces prior to forming the channel material. Monolithic three-dimensional memory devices formed by the embodiment methods are also disclosed.
    Type: Application
    Filed: October 24, 2014
    Publication date: April 28, 2016
    Inventors: Sateesh KOKA, Raghuveer S. MAKALA, Yanli ZHANG, Senaka KANAKAMEDALA, Rahul SHARANGPANI, Yao-Sheng LEE, George MATAMIS
  • Patent number: 9305849
    Abstract: A monolithic three dimensional NAND string includes a semiconductor channel, an end part of the semiconductor channel extending substantially perpendicular to a major surface of a substrate, a plurality of control gate electrodes extending substantially parallel to the major surface of the substrate, a charge storage material layer located between the plurality of control gate electrodes and the semiconductor channel, a tunnel dielectric located between the charge storage material layer and the semiconductor channel, and a blocking dielectric containing a plurality of clam-shaped portions each having two horizontal portions connected by a vertical portion. Each of the plurality of control gate electrodes are located at least partially in an opening in the clam-shaped blocking dielectric, and a plurality of discrete cover oxide segments embedded in part of a thickness of the charge storage material layer and located between the blocking dielectric and the charge storage material layer.
    Type: Grant
    Filed: November 12, 2014
    Date of Patent: April 5, 2016
    Assignee: SANDISK TECHNOLOGIES INC.
    Inventors: Masanori Tsutsumi, Shigehiro Fujino, Sateesh Koka, Senaka Kanakamedala, Yanli Zhang, Raghuveer S. Makala, Rahul Sharangpani, George Matamis, Wei Zhao
  • Patent number: 9305932
    Abstract: A method of making a monolithic three dimensional NAND string includes providing a first stack of alternating first material layers and second material layers over a major surface of a substrate. The first material layers include first silicon oxide layers, the second material layers include second silicon oxide layers, and the first silicon oxide layers have a different etch rate from the second silicon oxide when exposed to the same etching medium. The first stack includes a back side opening, a front side opening, and at least a portion of a floating gate layer, a tunnel dielectric and a semiconductor channel located in the front side opening. The method also includes selectively removing the first material layers through the back side opening to form back side control gate recesses between adjacent second material layers.
    Type: Grant
    Filed: June 30, 2014
    Date of Patent: April 5, 2016
    Assignee: SANDISK TECHNOLOGIES INC.
    Inventors: Senaka Krishna Kanakamedala, Yanli Zhang, Raghuveer S. Makala, Yao-Sheng Lee, Johann Alsmeier, George Matamis
  • Publication number: 20160086972
    Abstract: A vertically repeating stack of a unit layer stack is formed over a substrate. The unit layer stack includes a sacrificial material layer, a lower silicon oxide material layer, a first silicon oxide material layer, and an upper silicon oxide material layer. A memory opening can be formed through the vertically repeating stack, and a layer stack including a blocking dielectric layer, a memory material layer, a tunneling dielectric, and a semiconductor channel can be formed in the memory opening. The sacrificial material layers are replaced with electrically conductive layers. The first silicon oxide material layer can be removed to form backside recesses. Optionally, portions of the memory material layer can be removed to from discrete charge storage regions. The backside recesses can be filled with a low-k dielectric material and/or can include cavities within a dielectric material to provide reduced coupling between electrically conductive layers.
    Type: Application
    Filed: December 3, 2015
    Publication date: March 24, 2016
    Inventors: Yanli ZHANG, James KAI, Raghuveer S. MAKALA, Jin LIU, Murshed CHOWDHURY, Camilla HUANG, Johann ALSMEIER
  • Publication number: 20160086969
    Abstract: A monolithic three dimensional NAND string includes a plurality of control gate electrodes extending substantially parallel to a major surface of a substrate in at least one active region, a plurality of semiconductor channels having at least one end portion of each of the plurality of semiconductor channels extending substantially perpendicular to the major surface of the substrate, at least one memory film located between each of the plurality of control gate electrodes and each respective semiconductor channel of the plurality of semiconductor channels, and at least one first slit trench extending substantially perpendicular to the major surface of the substrate. Each of the plurality of control gate electrodes has a nonlinear side wall adjacent to the at least one first slit trench in the at least one active region.
    Type: Application
    Filed: September 19, 2014
    Publication date: March 24, 2016
    Inventors: Yanli Zhang, Johann Alsmeier
  • Publication number: 20160071861
    Abstract: A three dimensional NAND device includes a common vertical channel and electrically isolated control gate electrodes on different lateral sides of the channel in each device level to form different lateral portions of a memory cell in each device level. Dielectric separator structures are located between and electrically isolate the control gate electrodes. The lateral portions of the memory cell in each device level may be electrically isolated by at least one of doping ungated portions of the channel adjacent to the separator structures or storing electrons in the separator structure.
    Type: Application
    Filed: June 24, 2015
    Publication date: March 10, 2016
    Inventors: Andrey Serov, James K. Kai, Yanli Zhang, Henry Chien, Johann Alsmeier
  • Publication number: 20160071860
    Abstract: A memory device includes a plurality of memory cells arranged in a string substantially perpendicular to the major surface of the substrate in a plurality of device levels, at least one first select gate electrode located between the major surface of the substrate and the plurality of memory cells, at least one second select gate electrode located above the plurality of memory cells, a semiconductor channel having a portion that extends vertically along a direction perpendicular to the major surface, a first memory film contacting a first side of the semiconductor channel, and a second memory film contacting a second side of the semiconductor channel. The second memory film is electrically isolated from the first memory film, and is located at a same level as the first memory film.
    Type: Application
    Filed: June 24, 2015
    Publication date: March 10, 2016
    Inventors: James K. Kai, Yanli Zhang, Henry Chien, Johann Alsmeier
  • Publication number: 20160064532
    Abstract: Methods of making a monolithic three dimensional NAND string that include forming a stack of alternating first material layers and second material layers over a substrate, where each of the second material layers includes a layer of a first silicon oxide material between two layers of a second silicon oxide material different from the first silicon oxide material, etching the stack to form a front side opening in the stack, forming a memory film over a sidewall of the front side opening, and forming a semiconductor channel in the front side opening such that at least a portion of the memory film is located between the semiconductor channel and the sidewall of the front side opening, where at least one of an air gap or a material which has a dielectric constant below 3.9 is formed between the respective two layers of second silicon oxide material.
    Type: Application
    Filed: August 26, 2014
    Publication date: March 3, 2016
    Inventors: Raghuveer S. MAKALA, Yanli ZHANG, Rahul SHARANGPANI, Yao-Sheng LEE, Senaka Krishna KANAKAMEDALA, George MATAMIS, Johann ALSMEIER
  • Publication number: 20160049421
    Abstract: A monolithic three dimensional NAND string includes a plurality of control gate electrodes extending substantially parallel to a major surface of a substrate, a memory opening extending substantially perpendicular to the major surface of the substrate and filled with a memory opening material including a memory film, and a dummy opening extending substantially perpendicular to the major surface of the substrate and filled with a dummy channel material which is different from the memory opening material. The dummy channel material has a higher Young's modulus than the memory opening material to offset warpage of the substrate due to the one of compressive and tensile stress imposed by the plurality of control gate electrodes on the substrate.
    Type: Application
    Filed: August 18, 2014
    Publication date: February 18, 2016
    Inventors: Yanli ZHANG, Raghuveer S. MAKALA, Johann ALSMEIER, Yao-Sheng LEE, Tiger XU
  • Patent number: 9240354
    Abstract: A semiconductor-on-insulator (SOI) substrate comprises a bulk semiconductor substrate, a buried insulator layer formed on the bulk substrate and an active semiconductor layer formed on the buried insulator layer. Impurities are implanted near the interface of the buried insulator layer and the active semiconductor layer. A diffusion barrier layer is formed between the impurities and an upper surface of the active semiconductor layer. The diffusion barrier layer prevents the impurities from diffusing therethrough.
    Type: Grant
    Filed: November 14, 2012
    Date of Patent: January 19, 2016
    Assignee: GLOBALFOUNDRIES INC.
    Inventors: Gregory G. Freeman, Kam Leung Lee, Chengwen Pei, Geng Wang, Yanli Zhang
  • Patent number: 9236396
    Abstract: A monolithic three dimensional NAND string includes a semiconductor channel, at least one end part of the semiconductor channel extending substantially perpendicular to a major surface of a substrate and a plurality of control gate electrodes extending substantially parallel to the major surface of the substrate. The NAND string also includes a memory film located between the semiconductor channel and the plurality of control gate electrodes and a blocking dielectric containing a plurality of clam-shaped portions each having two horizontal portions connected by a vertical portion. The NAND string also includes a plurality of discrete cover silicon oxide segments located between the memory film and each respective clam-shaped portion of the blocking dielectric containing a respective control gate electrode. Each of the plurality of cover silicon oxide segments has curved upper and lower sides and substantially straight vertical sidewalls.
    Type: Grant
    Filed: November 12, 2014
    Date of Patent: January 12, 2016
    Assignee: SANDISK TECHNOLOGIES INC.
    Inventors: Sateesh Koka, Senaka Kanakamedala, Yanli Zhang, Raghuveer S. Makala, Rahul Sharangpani, George Matamis, Wei Zhao
  • Publication number: 20150380424
    Abstract: A method of making a three dimensional NAND string includes providing a stack of alternating first material layers and second material layers over a substrate. The method further includes forming a front side opening in the stack, forming a tunnel dielectric in the front side opening, forming a semiconductor channel in the front side opening over the tunnel dielectric and forming a back side opening in the stack. The method also includes selectively removing the second material layers through the back side opening to form back side recesses between adjacent first material layers, forming a metal charge storage layer in the back side opening and in the back side recesses and forming discrete charge storage regions in the back side recesses by removing the metal charge storage layer from the back side opening and selectively recessing the metal charge storage layer in the back side recesses.
    Type: Application
    Filed: June 30, 2014
    Publication date: December 31, 2015
    Inventors: Raghuveer S. Makala, Yao-Sheng Lee, Senaka Krishna Kanakamedala, Yanli Zhang, George Matamis, Johann Alsmeier