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).
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Patent number: 10593519Abstract: 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: GrantFiled: July 27, 2017Date of Patent: March 17, 2020Assignee: TOKYO ELECTRON LIMITEDInventors: Norikazu Yamada, Toshifumi Tachikawa, Koichi Nagami
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Patent number: 10109461Abstract: 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: GrantFiled: July 6, 2017Date of Patent: October 23, 2018Assignees: TOKYO ELECTRON LIMITED, DAIHEN CORPORATIONInventors: Norikazu Yamada, Toshifumi Tachikawa, Koichi Nagami, Satoru Hamaishi, Koji Itadani
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Publication number: 20180012736Abstract: 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: ApplicationFiled: July 27, 2017Publication date: January 11, 2018Inventors: Norikazu Yamada, Toshifumi Tachikawa, Koichi Nagami
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Publication number: 20170372873Abstract: 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: ApplicationFiled: July 6, 2017Publication date: December 28, 2017Inventors: Norikazu Yamada, Toshifumi Tachikawa, Koichi Nagami, Satoru Hamaishi, Koji Itadani
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Patent number: 9754768Abstract: 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: GrantFiled: December 3, 2012Date of Patent: September 5, 2017Assignee: TOKYO ELECTRON LIMITEDInventors: Norikazu Yamada, Toshifumi Tachikawa, Koichi Nagami
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Patent number: 9734992Abstract: 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: GrantFiled: December 5, 2012Date of Patent: August 15, 2017Assignees: TOKYO ELECTRON LIMITED, DAIHEN CORPORATIONInventors: Norikazu Yamada, Toshifumi Tachikawa, Koichi Nagami, Satoru Hamaishi, Koji Itadani
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Patent number: 9355822Abstract: 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: GrantFiled: December 13, 2012Date of Patent: May 31, 2016Assignees: TOKYO ELECTRON LIMITED, DAIHEN CORPORATIONInventors: Norikazu Yamada, Toshifumi Tachikawa, Koichi Nagami, Tatsuya Ikenari, Daisuke Maehara
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Publication number: 20150000841Abstract: 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: ApplicationFiled: December 5, 2012Publication date: January 1, 2015Inventors: Norikazu Yamada, Toshifumi Tachikawa, Koichi Nagami, Satoru Hamaishi, Koji Itadani
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Publication number: 20140361690Abstract: 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: ApplicationFiled: December 13, 2012Publication date: December 11, 2014Inventors: Norikazu Yamada, Toshifumi Tachikawa, Koichi Nagami, Tatsuya Ikenari, Daisuke Maehara
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Publication number: 20140305905Abstract: 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: ApplicationFiled: December 3, 2012Publication date: October 16, 2014Inventors: Norikazu Yamada, Toshifumi Tachikawa, Koichi Nagami