Patents by Inventor Yao-Sheng Lee

Yao-Sheng Lee 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: 20150076584
    Abstract: A memory device and a method of fabricating a memory device that includes forming a protrusion over a substrate, an etch stop layer over the protrusion, and a stack of alternating material layers over the etch stop layer. The method further includes etching the stack to the etch stop layer to form a memory opening having a first width dimension proximate to the etch stop layer, etching the etch stop layer to provide a void area between the protrusion and a bottom of the memory opening, where the void area has a second width dimension that is larger than the first width dimension, forming a memory film over a sidewall of the memory opening and within the void area over the top surface of the protrusion, etching the memory film to expose the protrusion, and forming a semiconductor channel in the memory opening that is electrically coupled to the protrusion.
    Type: Application
    Filed: March 25, 2014
    Publication date: March 19, 2015
    Inventors: Jayavel Pachamuthu, Johann Alsmeier, Raghuveer S. Makala, Yao-Sheng Lee
  • Publication number: 20150079743
    Abstract: A method of fabricating a memory device, such as a three-dimensional NAND string, includes forming a trench through a stack of alternating first and second material layers to expose a source region of a semiconductor channel, partially filling the trench with a protective material, removing at least a portion of the alternating second material layers to form recesses between the first material layers, forming a conductive material in the recesses to form control gate electrodes for a memory device, depositing an insulating material over the sidewalls and bottom of the trench, etching through the insulating material and the protective material to expose the semiconductor channel at the trench bottom while leaving the insulating material on the trench sidewalls, and filling the trench with a source line that electrically contacts the source region while the insulating material is between the source line and the control gate electrodes along the trench sidewalls.
    Type: Application
    Filed: April 29, 2014
    Publication date: March 19, 2015
    Applicant: SanDisk Technologies, Inc.
    Inventors: Jayavel Pachamuthu, Johann Alsmeier, Raghuveer S. Makala, Yao-Sheng Lee
  • Publication number: 20150079742
    Abstract: A method of fabricating a semiconductor device, such as a three-dimensional NAND memory string, includes forming a first stack of alternating layers of a first material and a second material different from the first material over a substrate, removing a portion of the first stack to form a first trench, filling the trench with a sacrificial material, forming a second stack of alternating layers of the first material and the second material over the first stack and the sacrificial material, removing a portion of the second stack to the sacrificial material to form a second trench, and removing the sacrificial material to form a continuous trench through the first stack and the second stack.
    Type: Application
    Filed: April 29, 2014
    Publication date: March 19, 2015
    Applicant: SanDisk Technologies, Inc.
    Inventors: Jayavel Pachamuthu, Johann Alsmeier, Raghuveer S. Makala, Yao-Sheng Lee
  • Publication number: 20150069494
    Abstract: A monolithic three dimensional NAND string includes a vertical semiconductor channel and a plurality of control gate electrodes in different device levels. The string also includes a blocking dielectric layer, a charge storage region and a tunnel dielectric. A first control gate electrode is separated from a second control gate electrode by an air gap located between the major surfaces of the first and second control gate electrodes and/or the charge storage region includes silicide nanoparticles embedded in a charge storage dielectric.
    Type: Application
    Filed: November 18, 2014
    Publication date: March 12, 2015
    Inventors: Raghuveer S. Makala, Johann Alsmeier, Yao-Sheng Lee
  • Patent number: 8946023
    Abstract: A method of making a vertical NAND device includes forming a lower portion of a memory stack over a substrate, forming a lower portion of memory openings in the lower portion of the memory stack, and at least partially filling the lower portion of the memory openings with a sacrificial material. The method also includes forming an upper portion of the memory stack over the lower portion of the memory stack and over the sacrificial material, forming an upper portion of the memory openings in the upper portion of the memory stack to expose the sacrificial material in the lower portion of the memory openings, removing the sacrificial material to connect the lower portion of the memory openings with a respective upper portion of the memory openings to form continuous memory openings, and forming a semiconductor channel in each continuous memory opening.
    Type: Grant
    Filed: July 2, 2013
    Date of Patent: February 3, 2015
    Assignee: SanDisk Technologies Inc.
    Inventors: Raghuveer S. Makala, Yao-Sheng Lee, Jayavel Pachamuthu, Johann Alsmeier, Henry Chien
  • Patent number: 8933501
    Abstract: A monolithic three dimensional NAND string includes a vertical semiconductor channel and a plurality of control gate electrodes in different device levels. The string also includes a blocking dielectric layer, a charge storage region and a tunnel dielectric. A first control gate electrode is separated from a second control gate electrode by an air gap located between the major surfaces of the first and second control gate electrodes and/or the charge storage region includes silicide nanoparticles embedded in a charge storage dielectric.
    Type: Grant
    Filed: January 28, 2014
    Date of Patent: January 13, 2015
    Assignee: SanDisk Technologies Inc.
    Inventors: Raghuveer S. Makala, Johann Alsmeier, Yao-Sheng Lee
  • Publication number: 20150008503
    Abstract: A method of making a semiconductor device including forming a sacrificial feature over a substrate, forming a plurality of etch through regions having an etch through material and an etch stop region having an etch stop material over the sacrificial feature, forming a stack of alternating layers of a first material and a second material over the plurality of the etch through regions and the plurality of the etch stop regions, etching the stack to form a plurality of openings through the stack and through the etch through regions to expose the sacrificial feature, such that the etch through material is etched preferentially compared to the first and the second materials of the stack, removing the sacrificial feature through the plurality of openings and etching the stack to form a slit trench up to or only partially through the etch stop region, such that the first and the second materials of the stack are etched preferentially compared to the etch stop material.
    Type: Application
    Filed: July 2, 2013
    Publication date: January 8, 2015
    Inventors: Raghuveer S. MAKALA, Johann ALSMEIER, Yao-Sheng LEE, Masanori TERAHARA, Hirofumi WATATANI, Jayavel PACHAMUTHU
  • Publication number: 20140367762
    Abstract: A stack can be patterned by a first etch process to form an opening defining sidewall surfaces of a patterned material stack. A masking layer can be non-conformally deposited on sidewalls of an upper portion of the patterned material stack, while not being deposited on sidewalls of a lower portion of the patterned material stack. The sidewalls of a lower portion of the opening can be laterally recessed employing a second etch process, which can include an isotropic etch component. The sidewalls of the upper portion of the opening can protrude inward toward the opening to form an overhang over the sidewalls of the lower portion of the opening. The overhang can be employed to form useful structures such as an negative offset profile in a floating gate device or vertically aligned control gate electrodes for vertical memory devices.
    Type: Application
    Filed: August 29, 2014
    Publication date: December 18, 2014
    Inventors: Ming Tian, Jayavel Pachamuthu, Atsushi Suyama, James Kai, Raghuveer S. Makala, Yao-Sheng Lee, Johann Alsmeier, Henry Chien, Masanori Terahara, Hirofumi Watatani
  • Publication number: 20140367759
    Abstract: A method of making multi-level contacts. The method includes providing an in-process multilevel device including at least one device region and at least one contact region. The contact region includes a plurality of electrically conductive layers configured in a step pattern. The method also includes forming a conformal etch stop layer over the plurality of electrically conductive layers, forming a first electrically insulating layer over the etch stop layer, forming a conformal sacrificial layer over the first electrically insulating layer and forming a second electrically insulating layer over the sacrificial layer. The method also includes etching a plurality of contact openings through the etch stop layer, the first electrically insulating layer, the sacrificial layer and the second electrically insulating layer in the contact region to the plurality of electrically conductive layers.
    Type: Application
    Filed: August 27, 2014
    Publication date: December 18, 2014
    Inventors: Yao-Sheng Lee, Zhen Chen, Syo Fukata
  • Publication number: 20140353738
    Abstract: A method of making a monolithic three dimensional NAND string including providing a stack of alternating first material layers and second material layers over a substrate. The first material layers comprise an insulating material and the second material layers comprise sacrificial layers. The method also includes forming a back side opening in the stack, selectively removing the second material layers through the back side opening to form back side recesses between adjacent first material layers and forming a blocking dielectric inside the back side recesses and the back side opening. The blocking dielectric has a clam shaped regions inside the back side recesses. The method also includes forming a plurality of copper control gate electrodes in the respective clam shell shaped regions of the blocking dielectric in the back side recesses.
    Type: Application
    Filed: August 20, 2014
    Publication date: December 4, 2014
    Inventors: Raghuveer S. Makala, Yanli Zhang, Yao-Sheng Lee, Senaka Krishna Kanakamedala, Rahul Sharangpani, George Matamis, Johann Alsmeier, Seiji Shimabukuro, Genta Mizuno, Naoki Takeguchi
  • Publication number: 20140295636
    Abstract: A method of making a semiconductor device includes forming a stack of alternating layers of a first material and a second material over a substrate, etching the stack to form at least one opening extending partially through the stack and forming a masking layer on a sidewall and bottom surface of the at least one opening. The method also includes removing the masking layer from the bottom surface of the at least one opening while leaving the masking layer on the sidewall of the at least one opening, and further etching the at least one opening to extend the at least one opening further through the stack while the masking layer remains on the sidewall of the at least one opening.
    Type: Application
    Filed: December 20, 2013
    Publication date: October 2, 2014
    Applicant: SanDisk Technologies, Inc.
    Inventors: Raghuveer S. Makala, Yao-Sheng Lee, Johann Alsmeier, Henry Chien, Masanori Terahara, Hirofumi Watatani
  • Publication number: 20140273373
    Abstract: A method of making a vertical NAND device includes forming a lower portion of a memory stack over a substrate, forming a lower portion of memory openings in the lower portion of the memory stack, and at least partially filling the lower portion of the memory openings with a sacrificial material. The method also includes forming an upper portion of the memory stack over the lower portion of the memory stack and over the sacrificial material, forming an upper portion of the memory openings in the upper portion of the memory stack to expose the sacrificial material in the lower portion of the memory openings, removing the sacrificial material to connect the lower portion of the memory openings with a respective upper portion of the memory openings to form continuous memory openings, and forming a semiconductor channel in each continuous memory opening.
    Type: Application
    Filed: July 2, 2013
    Publication date: September 18, 2014
    Applicant: SanDisk Technologies, Inc.
    Inventors: Raghuveer S. MAKALA, Yao-Sheng LEE, Jayavel PACHAMUTHU, Johann ALSMEIER, Henry CHIEN
  • Patent number: 8828884
    Abstract: A method of making multi-level contacts. The method includes providing an in-process multilevel device including at least one device region and at least one contact region. The contact region includes a plurality of electrically conductive layers configured in a step pattern. The method also includes forming a conformal etch stop layer over the plurality of electrically conductive layers, forming a first electrically insulating layer over the etch stop layer, forming a conformal sacrificial layer over the first electrically insulating layer and forming a second electrically insulating layer over the sacrificial layer. The method also includes etching a plurality of contact openings through the etch stop layer, the first electrically insulating layer, the sacrificial layer and the second electrically insulating layer in the contact region to the plurality of electrically conductive layers.
    Type: Grant
    Filed: May 23, 2012
    Date of Patent: September 9, 2014
    Assignee: Sandisk Technologies Inc.
    Inventors: Yao-Sheng Lee, Zhen Chen, Syo Fukata
  • Publication number: 20140138760
    Abstract: A monolithic three dimensional NAND string includes a vertical semiconductor channel and a plurality of control gate electrodes in different device levels. The string also includes a blocking dielectric layer, a charge storage region and a tunnel dielectric. A first control gate electrode is separated from a second control gate electrode by an air gap located between the major surfaces of the first and second control gate electrodes and/or the charge storage region includes silicide nanoparticles embedded in a charge storage dielectric.
    Type: Application
    Filed: January 28, 2014
    Publication date: May 22, 2014
    Applicant: SANDISK TECHNOLOGIES INC.
    Inventors: Raghuveer S. Makala, Johann Alsmeier, Yao-Sheng Lee
  • Publication number: 20140054670
    Abstract: A three dimensional memory device including a substrate and a semiconductor channel. At least one end portion of the semiconductor channel extends substantially perpendicular to a major surface of the substrate. The device also includes at least one charge storage region located adjacent to semiconductor channel and a plurality of control gate electrodes having a strip shape extending substantially parallel to the major surface of the substrate. The plurality of control gate electrodes include at least a first control gate electrode located in a first device level and a second control gate electrode located in a second device level located over the major surface of the substrate and below the first device level. The device also includes an etch stop layer located between the substrate and the plurality of control gate electrodes.
    Type: Application
    Filed: October 30, 2013
    Publication date: February 27, 2014
    Applicant: SanDisk Technologies, Inc.
    Inventors: Yao-Sheng Lee, Johann Alsmeier
  • Patent number: 8658499
    Abstract: A monolithic three dimensional NAND string includes a vertical semiconductor channel and a plurality of control gate electrodes in different device levels. The string also includes a blocking dielectric layer, a charge storage region and a tunnel dielectric. A first control gate electrode is separated from a second control gate electrode by an air gap located between the major surfaces of the first and second control gate electrodes and/or the charge storage region includes silicide nanoparticles embedded in a charge storage dielectric.
    Type: Grant
    Filed: July 9, 2012
    Date of Patent: February 25, 2014
    Assignee: SanDisk Technologies Inc.
    Inventors: Raghuveer S. Makala, Johann Alsmeier, Yao-Sheng Lee
  • Publication number: 20140008714
    Abstract: A monolithic three dimensional NAND string includes a vertical semiconductor channel and a plurality of control gate electrodes in different device levels. The string also includes a blocking dielectric layer, a charge storage region and a tunnel dielectric. A first control gate electrode is separated from a second control gate electrode by an air gap located between the major surfaces of the first and second control gate electrodes and/or the charge storage region includes silicide nanoparticles embedded in a charge storage dielectric.
    Type: Application
    Filed: July 9, 2012
    Publication date: January 9, 2014
    Applicant: SanDisk Technologies Inc.
    Inventors: Raghuveer S. Makala, Johann Alsmeier, Yao-Sheng Lee
  • Patent number: 8614126
    Abstract: A three dimensional memory device including a substrate and a semiconductor channel. At least one end portion of the semiconductor channel extends substantially perpendicular to a major surface of the substrate. The device also includes at least one charge storage region located adjacent to semiconductor channel and a plurality of control gate electrodes having a strip shape extending substantially parallel to the major surface of the substrate. The plurality of control gate electrodes include at least a first control gate electrode located in a first device level and a second control gate electrode located in a second device level located over the major surface of the substrate and below the first device level. The device also includes an etch stop layer located between the substrate and the plurality of control gate electrodes.
    Type: Grant
    Filed: August 15, 2012
    Date of Patent: December 24, 2013
    Assignee: SanDisk Technologies Inc.
    Inventors: Yao-Sheng Lee, Johann Alsmeier
  • Publication number: 20130313627
    Abstract: A method of making multi-level contacts. The method includes providing an in-process multilevel device including at least one device region and at least one contact region. The contact region includes a plurality of electrically conductive layers configured in a step pattern. The method also includes forming a conformal etch stop layer over the plurality of electrically conductive layers, forming a first electrically insulating layer over the etch stop layer, forming a conformal sacrificial layer over the first electrically insulating layer and forming a second electrically insulating layer over the sacrificial layer. The method also includes etching a plurality of contact openings through the etch stop layer, the first electrically insulating layer, the sacrificial layer and the second electrically insulating layer in the contact region to the plurality of electrically conductive layers.
    Type: Application
    Filed: May 23, 2012
    Publication date: November 28, 2013
    Applicant: SanDisk Technologies, Inc.
    Inventors: Yao-Sheng Lee, Zhen Chen, Syo Fukata
  • Publication number: 20130229846
    Abstract: A three-dimensional memory is formed as an array of memory elements across multiple layers positioned at different distances above a semiconductor substrate. Cylindrical stacks of memory elements are formed where a cylindrical opening has read/write material deposited along its wall, and a cylindrical vertical bit line formed along its central axis. Memory elements formed on either side of such a cylinder may include sheet electrodes that extend into the read/write material.
    Type: Application
    Filed: March 7, 2013
    Publication date: September 5, 2013
    Applicant: SanDisk 3D LLC
    Inventors: Henry Chien, Yao-Sheng Lee, George Samachisa, Johann Alsmeier