Patents by Inventor Kenta Chito

Kenta Chito 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: 11456213
    Abstract: There is provided a processing method of a wafer having a functional layer on a front surface side. The processing method includes a laser processing step of forming laser processed grooves along streets while removing the functional layer along the streets by executing irradiation with a laser beam and a cut groove forming step of forming cut grooves inside the laser processed grooves along the streets by cutting the wafer by a cutting blade. The processing method also includes a grinding step of causing the cut grooves to be exposed on a back surface side of the wafer and dividing the wafer into plural device chips by grinding the back surface side of the wafer and thinning the wafer and a processing distortion removal step of supplying a gas in a plasma state to the back surface side of the wafer and removing processing distortion.
    Type: Grant
    Filed: September 10, 2020
    Date of Patent: September 27, 2022
    Assignee: DISCO CORPORATION
    Inventors: Yoshiteru Nishida, Hidekazu Iida, Kenta Chito
  • Patent number: 10957593
    Abstract: A method of processing a wafer includes a grinding step of grinding a wafer that has first insulating films covering via electrodes, from a reverse side thereof, an electrode protruding step of protruding the via electrodes covered with the first insulating films from the reverse side by way of etching, a distorted layer forming step of forming a distorted layer on the reverse side of the wafer, an insulating film forming step of forming a second insulating film on the reverse side of the wafer, and an electrode forming step of removing the first insulating films and the second insulating film from the regions where they overlap the via electrodes, and forming reverse-side electrodes connected to the via electrodes.
    Type: Grant
    Filed: December 2, 2019
    Date of Patent: March 23, 2021
    Assignee: DISCO CORPORATION
    Inventors: Yoshiteru Nishida, Hidekazu Iida, Kenta Chito, Youngsuk Kim
  • Publication number: 20210082763
    Abstract: There is provided a processing method of a wafer having a functional layer on a front surface side. The processing method includes a laser processing step of forming laser processed grooves along streets while removing the functional layer along the streets by executing irradiation with a laser beam and a cut groove forming step of forming cut grooves inside the laser processed grooves along the streets by cutting the wafer by a cutting blade. The processing method also includes a grinding step of causing the cut grooves to be exposed on a back surface side of the wafer and dividing the wafer into plural device chips by grinding the back surface side of the wafer and thinning the wafer and a processing distortion removal step of supplying a gas in a plasma state to the back surface side of the wafer and removing processing distortion.
    Type: Application
    Filed: September 10, 2020
    Publication date: March 18, 2021
    Inventors: Yoshiteru NISHIDA, Hidekazu IIDA, Kenta CHITO
  • Patent number: 10910246
    Abstract: Disclosed herein is a hold checking method for checking whether or not a wafer is held by an electrostatic chuck in loading the wafer to the electrostatic chuck by operating a transfer unit holding the wafer. The hold checking method includes a connecting step of bringing the wafer held by a transfer pad into contact with the electrostatic chuck to thereby connect the transfer pad through the wafer to the electrostatic chuck, and a hold determining step of supplying electric power from a DC power source through first wiring to the electrostatic chuck after performing the connecting step, and next determining that the wafer is held by the electrostatic chuck when the voltage across a resistor inserted in the first wiring has reached a predetermined voltage value.
    Type: Grant
    Filed: July 13, 2017
    Date of Patent: February 2, 2021
    Assignee: DISCO CORPORATION
    Inventor: Kenta Chito
  • Patent number: 10896836
    Abstract: An electrostatic chuck is provided and has a holding surface for holding a wafer with a tape attached to one side of the wafer where the tape is in contact with the holding surface. The electrostatic chuck includes a disk-shaped member having a plurality of fine holes communicating with a vacuum source, where the fine holes are exposed to the holding surface. The disk-shaped member also includes a plurality of asperities formed on the holding surface and connected to the fine holes, and an electrode embedded in the disk-shaped member. The vacuum source is operated to produce a vacuum on the holding surface through the fine holes and thereby hold the wafer through the tape on the holding surface under suction, where the asperities formed on the holding surface function as a suction passage communicating with the fine holes.
    Type: Grant
    Filed: July 13, 2018
    Date of Patent: January 19, 2021
    Assignee: DISCO CORPORATION
    Inventors: Kenta Chito, Hidekazu Iida, Tomohiro Yamada, Yoshiteru Nishida, Hiroyuki Takahashi, Ryoko Fujiya, Susumu Yokoo
  • Patent number: 10790192
    Abstract: A method for processing a wafer in which patterns including a metal layer are formed on streets. The method includes: a step of applying a laser beam along the streets formed with the patterns to form laser processed grooves while removing the patterns; a step of forming cut grooves having a depth in excess of a finished thickness of the wafer, inside the laser processed grooves; a step of grinding the back surface side of the wafer to thin the wafer to the finished thickness and to expose the cut grooves to the back surface of the wafer, thereby dividing the wafer into a plurality of device chips; a step of removing a crushed layer formed on the back surface side of the wafer; and a step of forming a strain layer on the back surface side of the wafer by plasma processing using an inert gas.
    Type: Grant
    Filed: April 4, 2019
    Date of Patent: September 29, 2020
    Assignee: DISCO CORPORATION
    Inventors: Yoshiteru Nishida, Hidekazu Iida, Susumu Yokoo, Hiroyuki Takahashi, Kenta Chito
  • Patent number: 10790193
    Abstract: A method for processing a wafer in which patterns including a metal layer are formed on streets. The method includes: a step of applying a laser beam along the streets formed with the patterns to form laser processed grooves having a depth in excess of a finished thickness of the wafer while removing the patterns; a step of grinding a back surface side of the wafer to thin the wafer to the finished thickness, and to expose the laser processed grooves to the back surface of the wafer, thereby dividing the wafer into a plurality of device chips; a step of removing a crushed layer formed on the back surface side of the wafer; and a step of forming a strain layer on the back surface side of the wafer by plasma processing using an inert gas.
    Type: Grant
    Filed: April 4, 2019
    Date of Patent: September 29, 2020
    Assignee: DISCO Corporation
    Inventors: Yoshiteru Nishida, Hidekazu Iida, Susumu Yokoo, Hiroyuki Takahashi, Kenta Chito
  • Publication number: 20200176313
    Abstract: A method of processing a wafer includes a grinding step of grinding a wafer that has first insulating films covering via electrodes, from a reverse side thereof, an electrode protruding step of protruding the via electrodes covered with the first insulating films from the reverse side by way of etching, a distorted layer forming step of forming a distorted layer on the reverse side of the wafer, an insulating film forming step of forming a second insulating film on the reverse side of the wafer, and an electrode forming step of removing the first insulating films and the second insulating film from the regions where they overlap the via electrodes, and forming reverse-side electrodes connected to the via electrodes.
    Type: Application
    Filed: December 2, 2019
    Publication date: June 4, 2020
    Inventors: Yoshiteru NISHIDA, Hidekazu IIDA, Kenta CHITO, Youngsuk KIM
  • Patent number: 10665492
    Abstract: Disclosed herein is a wafer unloading method for unloading a wafer from an electrostatic chuck table electrostatically holding the wafer by applying a voltage to the electrostatic chuck table. The wafer unloading method includes a voltage application stopping step of stopping the application of the voltage to the electrostatic chuck table electrostatically holding the wafer, a static eliminating voltage applying step of passing a current reverse in direction to a current passed to the electrostatic chuck table for electrostatically holding the wafer after performing the voltage application stopping step, thereby applying a static eliminating voltage for canceling peeling electrification to the electrostatic chuck table, and an unholding step of unholding the wafer from the electrostatic chuck table in the condition where the static eliminating voltage is kept applied to the electrostatic chuck table, after performing the static eliminating voltage applying step.
    Type: Grant
    Filed: April 11, 2018
    Date of Patent: May 26, 2020
    Assignee: DISCO CORPORATION
    Inventor: Kenta Chito
  • Patent number: 10453719
    Abstract: Disclosed herein is a plasma etching method for plasma-etching a ground surface of a wafer after the wafer with a tape attached to its lower surface is ground. The plasma etching method includes a drying step of applying heat to the tape to remove water present in the tape, an electrostatic holding step of electrostatically holding the wafer by an electrostatic force generated by supplying DC power to electrodes of an electrostatic chuck, after the drying step, and an etching step of reducing the pressure of a reduced-pressure chamber and plasma-etching the ground surface of the wafer by a reaction gas brought into a plasma state, after the electrostatic holding step.
    Type: Grant
    Filed: February 15, 2018
    Date of Patent: October 22, 2019
    Assignee: DISCO CORPORATION
    Inventor: Kenta Chito
  • Publication number: 20190311952
    Abstract: A method for processing a wafer in which patterns including a metal layer are formed on streets. The method includes: a step of applying a laser beam along the streets formed with the patterns to form laser processed grooves having a depth in excess of a finished thickness of the wafer while removing the patterns; a step of grinding a back surface side of the wafer to thin the wafer to the finished thickness, and to expose the laser processed grooves to the back surface of the wafer, thereby dividing the wafer into a plurality of device chips; a step of removing a crushed layer formed on the back surface side of the wafer; and a step of forming a strain layer on the back surface side of the wafer by plasma processing using an inert gas.
    Type: Application
    Filed: April 4, 2019
    Publication date: October 10, 2019
    Inventors: Yoshiteru NISHIDA, Hidekazu IIDA, Susumu YOKOO, Hiroyuki TAKAHASHI, Kenta CHITO
  • Publication number: 20190311951
    Abstract: A method for processing a wafer in which patterns including a metal layer are formed on streets. The method includes: a step of applying a laser beam along the streets formed with the patterns to form laser processed grooves while removing the patterns; a step of forming cut grooves having a depth in excess of a finished thickness of the wafer, inside the laser processed grooves; a step of grinding the back surface side of the wafer to thin the wafer to the finished thickness and to expose the cut grooves to the back surface of the wafer, thereby dividing the wafer into a plurality of device chips; a step of removing a crushed layer formed on the back surface side of the wafer; and a step of forming a strain layer on the back surface side of the wafer by plasma processing using an inert gas.
    Type: Application
    Filed: April 4, 2019
    Publication date: October 10, 2019
    Inventors: Yoshiteru NISHIDA, Hidekazu IIDA, Susumu YOKOO, Hiroyuki TAKAHASHI, Kenta CHITO
  • Publication number: 20190019712
    Abstract: Disclosed herein is an electrostatic chuck having a holding surface for holding a wafer with a tape attached to one side of the wafer in the condition where the tape is in contact with the holding surface. The electrostatic chuck includes a disk-shaped member having a plurality of fine holes communicating with a vacuum source, the fine holes being exposed to the holding surface, a plurality of asperities formed on the holding surface and connected to the fine holes, and an electrode embedded in the disk-shaped member. When the vacuum source is operated to produce a vacuum on the holding surface through the fine holes and thereby hold the wafer through the tape on the holding surface under suction, the asperities formed on the holding surface function as a suction passage communicating with the fine holes.
    Type: Application
    Filed: July 13, 2018
    Publication date: January 17, 2019
    Inventors: Kenta Chito, Hidekazu Iida, Tomohiro Yamada, Yoshiteru Nishida, Hiroyuki Takahashi, Ryoko Fujiya, Susumu Yokoo
  • Publication number: 20180301363
    Abstract: Disclosed herein is a wafer unloading method for unloading a wafer from an electrostatic chuck table electrostatically holding the wafer by applying a voltage to the electrostatic chuck table. The wafer unloading method includes a voltage application stopping step of stopping the application of the voltage to the electrostatic chuck table electrostatically holding the wafer, a static eliminating voltage applying step of passing a current reverse in direction to a current passed to the electrostatic chuck table for electrostatically holding the wafer after performing the voltage application stopping step, thereby applying a static eliminating voltage for canceling peeling electrification to the electrostatic chuck table, and an unholding step of unholding the wafer from the electrostatic chuck table in the condition where the static eliminating voltage is kept applied to the electrostatic chuck table, after performing the static eliminating voltage applying step.
    Type: Application
    Filed: April 11, 2018
    Publication date: October 18, 2018
    Inventor: Kenta Chito
  • Publication number: 20180240690
    Abstract: Disclosed herein is a plasma etching method for plasma-etching a ground surface of a wafer after the wafer with a tape attached to its lower surface is ground. The plasma etching method includes a drying step of applying heat to the tape to remove water present in the tape, an electrostatic holding step of electrostatically holding the wafer by an electrostatic force generated by supplying DC power to electrodes of an electrostatic chuck, after the drying step, and an etching step of reducing the pressure of a reduced-pressure chamber and plasma-etching the ground surface of the wafer by a reaction gas brought into a plasma state, after the electrostatic holding step.
    Type: Application
    Filed: February 15, 2018
    Publication date: August 23, 2018
    Inventor: Kenta Chito
  • Publication number: 20180025928
    Abstract: Disclosed herein is a hold checking method for checking whether or not a wafer is held by an electrostatic chuck in loading the wafer to the electrostatic chuck by operating a transfer unit holding the wafer. The hold checking method includes a connecting step of bringing the wafer held by a transfer pad into contact with the electrostatic chuck to thereby connect the transfer pad through the wafer to the electrostatic chuck, and a hold determining step of supplying electric power from a DC power source through first wiring to the electrostatic chuck after performing the connecting step, and next determining that the wafer is held by the electrostatic chuck when the voltage across a resistor inserted in the first wiring has reached a predetermined voltage value.
    Type: Application
    Filed: July 13, 2017
    Publication date: January 25, 2018
    Inventor: Kenta Chito