Patents by Inventor Toshifumi Tachikawa

Toshifumi Tachikawa 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: 10593519
    Abstract: At a time point T0 when starting a process, a duty ratio of a high frequency power RF1 to which power modulation is performed is set to be an initial value (about 90%) which allows plasma to be ignited securely under any power modulating conditions. At the substantially same time of starting the process, the duty ratio of the high frequency power RF1 is gradually reduced from the initial value (about 90%) in a regular negative gradient or in a ramp waveform. At a time point t2 after a lapse of a preset time Td, the duty ratio has an originally set value Ds for an etching process. After the time point t2, the duty ratio is fixed or maintained at the set value Ds until the end (time point T4) of the process.
    Type: Grant
    Filed: July 27, 2017
    Date of Patent: March 17, 2020
    Assignee: TOKYO ELECTRON LIMITED
    Inventors: Norikazu Yamada, Toshifumi Tachikawa, Koichi Nagami
  • Patent number: 10109461
    Abstract: A plasma processing method for performing a plasma process on a substrate in a plasma processing apparatus is provided. The plasma processing method comprises: a sampling-average-value calculating process of sampling voltage detection signals and electric current detection signals and calculating an average value of these signals during a first monitoring time; a moving-average-value calculating process of calculating a moving average value of the voltage detection signals and the electric current detection signals; a load impedance-measurement-value calculating process of calculating a measurement value of a load impedance with respect to a first high frequency power supply; and a reactance control process of controlling a reactance of a variable reactance element such that the measurement value of the load impedance is equal or approximate to a preset matching point corresponding to impedance on the side of the first high frequency power supply.
    Type: Grant
    Filed: July 6, 2017
    Date of Patent: October 23, 2018
    Assignees: TOKYO ELECTRON LIMITED, DAIHEN CORPORATION
    Inventors: Norikazu Yamada, Toshifumi Tachikawa, Koichi Nagami, Satoru Hamaishi, Koji Itadani
  • Publication number: 20180012736
    Abstract: At a time point T0 when starting a process, a duty ratio of a high frequency power RF1 to which power modulation is performed is set to be an initial value (about 90%) which allows plasma to be ignited securely under any power modulating conditions. At the substantially same time of starting the process, the duty ratio of the high frequency power RF1 is gradually reduced from the initial value (about 90%) in a regular negative gradient or in a ramp waveform. At a time point t2 after a lapse of a preset time Td, the duty ratio has an originally set value Ds for an etching process. After the time point t2, the duty ratio is fixed or maintained at the set value Ds until the end (time point T4) of the process.
    Type: Application
    Filed: July 27, 2017
    Publication date: January 11, 2018
    Inventors: Norikazu Yamada, Toshifumi Tachikawa, Koichi Nagami
  • Publication number: 20170372873
    Abstract: A plasma processing method for performing a plasma process on a substrate in a plasma processing apparatus is provided. The plasma processing method comprises: a sampling-average-value calculating process of sampling voltage detection signals and electric current detection signals and calculating an average value of these signals during a first monitoring time; a moving-average-value calculating process of calculating a moving average value of the voltage detection signals and the electric current detection signals; a load impedance-measurement-value calculating process of calculating a measurement value of a load impedance with respect to a first high frequency power supply; and a reactance control process of controlling a reactance of a variable reactance element such that the measurement value of the load impedance is equal or approximate to a preset matching point corresponding to impedance on the side of the first high frequency power supply.
    Type: Application
    Filed: July 6, 2017
    Publication date: December 28, 2017
    Inventors: Norikazu Yamada, Toshifumi Tachikawa, Koichi Nagami, Satoru Hamaishi, Koji Itadani
  • Patent number: 9754768
    Abstract: At a time point T0 when starting a process, a duty ratio of a high frequency power RF1 to which power modulation is performed is set to be an initial value (about 90%) which allows plasma to be ignited securely under any power modulating conditions. At the substantially same time of starting the process, the duty ratio of the high frequency power RF1 is gradually reduced from the initial value (about 90%) in a regular negative gradient or in a ramp waveform. At a time point t2 after a lapse of a preset time Td, the duty ratio has an originally set value Ds for an etching process. After the time point t2, the duty ratio is fixed or maintained at the set value Ds until the end (time point T4) of the process.
    Type: Grant
    Filed: December 3, 2012
    Date of Patent: September 5, 2017
    Assignee: TOKYO ELECTRON LIMITED
    Inventors: Norikazu Yamada, Toshifumi Tachikawa, Koichi Nagami
  • Patent number: 9734992
    Abstract: A plasma processing apparatus performs a stable and accurate matching operation with high reproducibility in a power modulation process of modulating of a high frequency power to be supplied into a processing vessel in a pulse shape. In the plasma processing apparatus, an impedance sensor 96A provided in a matching device performs a dual sampling averaging process on a RF voltage measurement value and an electric current measurement value respectively obtained from a RF voltage detector 100A of a voltage sensor system and a RF electric current detector 108A of an electric current sensor system by sampling-average-value calculating circuits 104A and 112A and by moving-average-value calculating circuits 106A and 114A. Thus, an update speed of a load impedance measurement value outputted from the impedance sensor 96A can be matched well with a driving control speed of a motor in a matching controller.
    Type: Grant
    Filed: December 5, 2012
    Date of Patent: August 15, 2017
    Assignees: TOKYO ELECTRON LIMITED, DAIHEN CORPORATION
    Inventors: Norikazu Yamada, Toshifumi Tachikawa, Koichi Nagami, Satoru Hamaishi, Koji Itadani
  • Patent number: 9355822
    Abstract: In a capacitively coupled plasma processing apparatus, a susceptor (lower electrode) 16 within a decompression chamber 10 faces an upper electrode 46 serving as a shower head. The susceptor 16 is electrically connected with a first high frequency power supply 36 and a second high frequency power supply 38 via matching devices 40 and 42, respectively. The first high frequency power supply 36 is formed of a linear amplifier type high frequency power supply and outputs a first high frequency power RF1 for plasma generation. The second high frequency power supply 38 is formed of a switching type high frequency power supply and outputs a second high frequency power RF2 for ion attraction. A residual high frequency power removing unit 74 is connected to a high frequency power supply line 45 on a side of the second high frequency power supply 38.
    Type: Grant
    Filed: December 13, 2012
    Date of Patent: May 31, 2016
    Assignees: TOKYO ELECTRON LIMITED, DAIHEN CORPORATION
    Inventors: Norikazu Yamada, Toshifumi Tachikawa, Koichi Nagami, Tatsuya Ikenari, Daisuke Maehara
  • Publication number: 20150000841
    Abstract: A plasma processing apparatus performs a stable and accurate matching operation with high reproducibility in a power modulation process of modulating of a high frequency power to be supplied into a processing vessel in a pulse shape. In the plasma processing apparatus, an impedance sensor 96A provided in a matching device performs a dual sampling averaging process on a RF voltage measurement value and an electric current measurement value respectively obtained from a RF voltage detector 100A of a voltage sensor system and a RF electric current detector 108A of an electric current sensor system by sampling-average-value calculating circuits 104A and 112A and by moving-average-value calculating circuits 106A and 114A. Thus, an update speed of a load impedance measurement value outputted from the impedance sensor 96A can be matched well with a driving control speed of a motor in a matching controller.
    Type: Application
    Filed: December 5, 2012
    Publication date: January 1, 2015
    Inventors: Norikazu Yamada, Toshifumi Tachikawa, Koichi Nagami, Satoru Hamaishi, Koji Itadani
  • Publication number: 20140361690
    Abstract: In a capacitively coupled plasma processing apparatus, a susceptor (lower electrode) 16 within a decompression chamber 10 faces an upper electrode 46 serving as a shower head. The susceptor 16 is electrically connected with a first high frequency power supply 36 and a second high frequency power supply 38 via matching devices 40 and 42, respectively. The first high frequency power supply 36 is formed of a linear amplifier type high frequency power supply and outputs a first high frequency power RF1 for plasma generation. The second high frequency power supply 38 is formed of a switching type high frequency power supply and outputs a second high frequency power RF2 for ion attraction. A residual high frequency power removing unit 74 is connected to a high frequency power supply line 45 on a side of the second high frequency power supply 38.
    Type: Application
    Filed: December 13, 2012
    Publication date: December 11, 2014
    Inventors: Norikazu Yamada, Toshifumi Tachikawa, Koichi Nagami, Tatsuya Ikenari, Daisuke Maehara
  • Publication number: 20140305905
    Abstract: At a time point T0 when starting a process, a duty ratio of a high frequency power RF1 to which power modulation is performed is set to be an initial value (about 90%) which allows plasma to be ignited securely under any power modulating conditions. At the substantially same time of starting the process, the duty ratio of the high frequency power RF1 is gradually reduced from the initial value (about 90%) in a regular negative gradient or in a ramp waveform. At a time point t2 after a lapse of a preset time Td, the duty ratio has an originally set value Ds for an etching process. After the time point t2, the duty ratio is fixed or maintained at the set value Ds until the end (time point T4) of the process.
    Type: Application
    Filed: December 3, 2012
    Publication date: October 16, 2014
    Inventors: Norikazu Yamada, Toshifumi Tachikawa, Koichi Nagami