Patents by Inventor Tatsuo Nishita

Tatsuo Nishita 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: 8569186
    Abstract: A plasma processing apparatus generates plasma by introducing microwaves into a processing chamber by using a planar antenna having a plurality of slots. By using the plasma processing apparatus, a nitrogen containing gas and a silicon containing gas introduced into the processing chamber are brought into the plasma state, and at the time of depositing by using the plasma a silicon nitride film on the surface of the a substrate to be processed, stress to the silicon nitride film to be formed is controlled by the combination of the type and the processing pressure of the nitrogen containing gas.
    Type: Grant
    Filed: November 13, 2012
    Date of Patent: October 29, 2013
    Assignee: Tokyo Electron Limited
    Inventors: Masayuki Kohno, Tatsuo Nishita, Toshio Nakanishi
  • Patent number: 8366953
    Abstract: A plasma cleaning method is performed in a plasma CVD apparatus for depositing a silicon nitride film on a surface of a target substrate, and includes a stage (S1) of supplying a cleaning gas containing NF3 gas into a process container, thereby removing extraneous deposits formed on portions inside the process container; a stage (S2) of supplying a gas containing hydrogen gas into the process container and generating plasma thereof, thereby removing residual fluorine inside the process container; and a stage (S3) of supplying a gas containing a rare gas into the process container and generating plasma thereof, thereby removing residual hydrogen inside the process container.
    Type: Grant
    Filed: September 18, 2007
    Date of Patent: February 5, 2013
    Assignee: Tokyo Electron Limited
    Inventors: Masayuki Kohno, Tatsuo Nishita, Toshio Nakanishi
  • Patent number: 8329596
    Abstract: A plasma processing apparatus generates plasma by introducing microwaves into a processing chamber by using a planar antenna having a plurality of slots. By using the plasma processing apparatus, a nitrogen containing gas and a silicon containing gas introduced into the processing chamber are brought into the plasma state, and at the time of depositing by using the plasma a silicon nitride film on the surface of the a substrate to be processed, stress to the silicon nitride film to be formed is controlled by the combination of the type and the processing pressure of the nitrogen containing gas.
    Type: Grant
    Filed: March 19, 2012
    Date of Patent: December 11, 2012
    Assignee: Tokyo Electron Limited
    Inventors: Masayuki Kohno, Tatsuo Nishita, Toshio Nakanishi
  • Patent number: 8318614
    Abstract: A Plasma processing apparatus (100) introduces microwaves into a chamber (1) by a plane antenna (31) which has a plurality of holes. A material gas, which contains a nitrogen-containing compound and a silicon-containing compound, is introduced into the chamber (1) by using the plasma processing apparatus, and plasma is generated by the microwaves. Then, a silicon nitride film is deposited by the plasma on a surface of an object to be processed. The trap density of the silicon nitride film is controlled by adjusting the conditions of the plasma CVD process.
    Type: Grant
    Filed: March 25, 2008
    Date of Patent: November 27, 2012
    Assignee: Tokyo Electron Limited
    Inventors: Masayuki Kohno, Tatsuo Nishita, Toshio Nakanishi, Yoshihiro Hirota
  • Patent number: 8258571
    Abstract: The invention provides a MOS semiconductor memory device that achieves excellent data retention characteristics while also achieving high-speed data write performance, low-power operation performance, and high reliability. A MOS semiconductor memory device 601 includes a first insulating film 111 and fifth insulating film 115 having large bandgaps 111a and 115a, a third insulating film 113 having the smallest bandgap 113a, and a second insulating film 112 and fourth insulating film 114 interposed between the third insulating film 113 and the first and fifth insulating films 111 and 115, respectively, and having intermediate bandgaps 112a and 114a.
    Type: Grant
    Filed: June 20, 2008
    Date of Patent: September 4, 2012
    Assignees: Tokyo Electron Limited, Tohoku University
    Inventors: Tetsuo Endoh, Masayuki Kohno, Tatsuo Nishita, Minoru Honda, Toshio Nakanishi, Yoshihiro Hirota
  • Publication number: 20120184107
    Abstract: In a semiconductor device manufacturing method, the formation of a sacrificial oxide film and removal thereof by wet etching and/or the formation of a silicon dioxide film and removal thereof by wet etching are performed. In the process for manufacturing a semiconductor device, the formation of the sacrificial oxide film and/or the silicon dioxide film is performed within a processing chamber of a plasma processing apparatus using a plasma in which O(1D2) radicals produced using a processing gas that contains oxygen are dominant.
    Type: Application
    Filed: September 29, 2010
    Publication date: July 19, 2012
    Applicant: TOKYO ELECTRON LIMITED
    Inventors: Yoshihiro Sato, Toshihiko Shiozawa, Tatsuo Nishita, Yoshihiro Hirota
  • Publication number: 20120178268
    Abstract: A plasma processing apparatus generates plasma by introducing microwaves into a processing chamber by using a planar antenna having a plurality of slots. By using the plasma processing apparatus, a nitrogen containing gas and a silicon containing gas introduced into the processing chamber are brought into the plasma state, and at the time of depositing by using the plasma a silicon nitride film on the surface of the a substrate to be processed, stress to the silicon nitride film to be formed is controlled by the combination of the type and the processing pressure of the nitrogen containing gas.
    Type: Application
    Filed: March 19, 2012
    Publication date: July 12, 2012
    Applicant: TOKYO ELECTRON LIMITED
    Inventors: Masayuki KOHNO, Tatsuo NISHITA, Toshio NAKANISHI
  • Patent number: 8138103
    Abstract: A plasma processing apparatus generates plasma by introducing microwaves into a processing chamber by using a planar antenna having a plurality of slots. By using the plasma processing apparatus, a nitrogen containing gas and a silicon containing gas introduced into the processing chamber are brought into the plasma state, and at the time of depositing by using the plasma a silicon nitride film on the surface of the a substrate to be processed, stress to the silicon nitride film to be formed is controlled by the combination of the type and the processing pressure of the nitrogen containing gas.
    Type: Grant
    Filed: May 30, 2007
    Date of Patent: March 20, 2012
    Assignee: Tokyo Electron Limited
    Inventors: Masayuki Kohno, Tatsuo Nishita, Toshio Nakanishi
  • Patent number: 8119545
    Abstract: Provided is a plasma CVD device. In the plasma CVD device, in producing a silicon nitride film while controlling the size of a band gap by CVD, microwaves are introduced into a treatment vessel by a flat antenna having a plurality of holes. The plasma CVD is carried out under a given treatment pressure selected from a pressure range of not less than 0.1 Pa and not more than 1333 Pa at a flow ratio between a silicon-containing compound gas and a nitrogen gas (silicon-containing compound gas flow rate/nitrogen gas flow rate) selected from a range of not less than 0.005 and not more than 0.2, whereby the Si/N ratio in the film is controlled to form a silicon nitride film having a band gap size of not less than 2.5 eV and not more than 7 eV.
    Type: Grant
    Filed: March 30, 2009
    Date of Patent: February 21, 2012
    Assignee: Tokyo Electron Limited
    Inventors: Minoru Honda, Toshio Nakanishi, Masayuki Kohno, Tatsuo Nishita, Junya Miyahara
  • Patent number: 8114790
    Abstract: A plasma processing apparatus includes a process chamber configured to be vacuum-exhausted; a worktable configured to place a target substrate thereon inside the process chamber; a microwave generation source configured to generate microwaves; a planar antenna including a plurality of slots and configured to supply microwaves generated by the microwave generation source through the slots into the process chamber; a gas supply mechanism configured to supply a film formation source gas into the process chamber; and an RF power supply configured to apply an RF power to the worktable. The apparatus is preset to turn a nitrogen-containing gas and a silicon-containing gas supplied in the process chamber into plasma by the microwaves, and to deposit a silicon nitride film on a surface of the target substrate by use of the plasma, while applying the RF power to the worktable.
    Type: Grant
    Filed: May 30, 2007
    Date of Patent: February 14, 2012
    Assignee: Tokyo Electron Limited
    Inventors: Masayuki Kohno, Tatsuo Nishita, Toshio Nakanishi
  • Publication number: 20110189862
    Abstract: Provided is a process of forming a silicon oxynitride film having concentration of hydrogen atoms below or equal to 9.9×1020 atoms/cm3 as measured by using secondary ion mass spectrometry (SIMS), using a plasma CVD device, which generates plasma by introducing microwaves into a process chamber by using a planar antenna having a plurality of apertures, by setting a pressure inside the process chamber within a range from 0.1 Pa to 6.7 Pa, and performing plasma CVD by using process gases including SiCl4 gas, nitrogen gas, and oxygen gas.
    Type: Application
    Filed: September 29, 2009
    Publication date: August 4, 2011
    Applicant: TOKYO ELECTRON LIMITED
    Inventors: Minoru Honda, Tatsuo Nishita, Junya Miyahara, Masayuki Kohno
  • Publication number: 20110086517
    Abstract: Disclosed is a plasma CVD device. In the plasma CVD device, in producing a silicon nitride film while controlling the size of a band gap by CVD, microwaves are introduced into a treatment vessel by a flat antenna having a plurality of holes. The plasma CVD is carried out under a given treatment pressure selected from a pressure range of not less than 0.1 Pa and not more than 1333 Pa at a flow ratio between a silicon-containing compound gas and a nitrogen gas (silicon-containing compound gas flow rate/nitrogen gas flow rate) selected from a range of not less than 0.005 and not more than 0.2, whereby the Si/N ratio in the film is controlled to form a silicon nitride film having a band gap size of not less than 2.5 eV and not more than 7 eV.
    Type: Application
    Filed: March 30, 2009
    Publication date: April 14, 2011
    Applicant: TOKYO ELECTRON LIMITED
    Inventors: Minoru Honda, Toshio Nakanishi, Masayuki Kohno, Tatsuo Nishita, Junya Miyahara
  • Patent number: 7915177
    Abstract: In the present invention, when a gate insulation film in a DRAM is formed, an oxide film constituting a base of the gate insulation film is plasma-nitrided. The plasma nitridation is performed with microwave plasma generated by using a plane antenna having a large number of through holes. Nitrogen concentration in the gate insulation film formed by the plasma nitridation is 5 to 20% in atomic percentage. Even without subsequent annealing, it is possible to effectively prevent a boron penetration phenomenon in the DRAM and to reduce traps in the film causing deterioration in driving capability of the device.
    Type: Grant
    Filed: January 27, 2010
    Date of Patent: March 29, 2011
    Assignee: Toyko Electron Limited
    Inventors: Tatsuo Nishita, Shuuichi Ishizuka, Yutaka Fujino, Toshio Nakanishi, Yoshihiro Sato
  • Publication number: 20100283097
    Abstract: The invention provides a MOS semiconductor memory device that achieves excellent data retention characteristics while also achieving high-speed data write performance, low-power operation performance, and high reliability. A MOS semiconductor memory device 601 includes a first insulating film 111 and fifth insulating film 115 having large bandgaps 111a and 115a, a third insulating film 113 having the smallest bandgap 113a, and a second insulating film 112 and fourth insulating film 114 interposed between the third insulating film 113 and the first and fifth insulating films 111 and 115, respectively, and having intermediate bandgaps 112a and 114a.
    Type: Application
    Filed: June 20, 2008
    Publication date: November 11, 2010
    Applicant: TOKYO ELECTRON LIMITED
    Inventors: Tetsuo Endoh, Masayuki Kohno, Tatsuo Nishita, Minoru Honda, Toshio Nakanishi, Yoshihiro Hirota
  • Publication number: 20100140683
    Abstract: Provided is a silicon nitride film which has an excellent charge storage capacity and thus is useful as a charge storage layer of a semiconductor memory device. The silicon nitride film having substantially uniform trap density in the film thickness direction has high charge storage performance. The silicon nitride film is formed by plasma CVD by using a plasma processing apparatus (100), wherein microwaves are introduced into a chamber (1) by a plane antenna having a plurality of holes, plasma is generated by the microwaves while a source gas including nitrogen-containing compound and silicon-containing compound is introduced into the chamber (1), and the silicon nitride film is deposited on the surface of a processing object by the plasma.
    Type: Application
    Filed: March 26, 2008
    Publication date: June 10, 2010
    Applicants: TOKYO ELECTRON LIMITED, HIROSHIMA UNIVERSITY
    Inventors: Seiichi Miyazaki, Masayuki Kohno, Tatsuo Nishita, Toshio Nakanishi, Yoshihiro Hirota
  • Publication number: 20100130023
    Abstract: In the present invention, when a gate insulation film in a DRAM is formed, an oxide film constituting a base of the gate insulation film is plasma-nitrided. The plasma nitridation is performed with microwave plasma generated by using a plane antenna having a large number of through holes. Nitrogen concentration in the gate insulation film formed by the plasma nitridation is 5 to 20% in atomic percentage. Even without subsequent annealing, it is possible to effectively prevent a boron penetration phenomenon in the DRAM and to reduce traps in the film causing deterioration in driving capability of the device.
    Type: Application
    Filed: January 27, 2010
    Publication date: May 27, 2010
    Applicant: TOKYO ELECTRON LIMITED
    Inventors: Tatsuo Nishita, Shuuichi Ishizuka, Yutaka Fujino, Toshio Nakanishi, Yoshihiro Sato
  • Patent number: 7674722
    Abstract: In the present invention, when a gate insulation film in a DRAM is formed, an oxide film constituting a base of the gate insulation film is plasma-nitrided. The plasma nitridation is performed with microwave plasma generated by using a plane antenna having a large number of through holes. Nitrogen concentration in the gate insulation film formed by the plasma nitridation is 5 to 20% in atomic percentage. Even without subsequent annealing, it is possible to effectively prevent a boron penetration phenomenon in the DRAM and to reduce traps in the film causing deterioration in driving capability of the device.
    Type: Grant
    Filed: October 27, 2005
    Date of Patent: March 9, 2010
    Assignee: Tokyo Electron Limited
    Inventors: Tatsuo Nishita, Shuuichi Ishizuka, Yutaka Fujino, Toshio Nakanishi, Yoshihiro Sato
  • Publication number: 20100052040
    Abstract: A Plasma processing apparatus (100) introduces microwaves into a chamber (1) by a plane antenna (31) which has a plurality of holes. A material gas, which contains a nitrogen-containing compound and a silicon-containing compound, is introduced into the chamber (1) by using the plasma processing apparatus, and plasma is generated by the microwaves. Then, a silicon nitride film is deposited by the plasma on a surface of an object to be processed. The trap density of the silicon nitride film is controlled by adjusting the conditions of the plasma CVD process.
    Type: Application
    Filed: March 25, 2008
    Publication date: March 4, 2010
    Applicant: Tokyo Electron Limited
    Inventors: Masayuki Kohno, Tatsuo Nishita, Toshio Nakanishi, Yoshihiro Hirota
  • Publication number: 20090308840
    Abstract: A plasma cleaning method is performed in a plasma CVD apparatus for depositing a silicon nitride film on a surface of a target substrate, and includes a stage (S1) of supplying a cleaning gas containing NF3 gas into a process container, thereby removing extraneous deposits formed on portions inside the process container; a stage (S2) of supplying a gas containing hydrogen gas into the process container and generating plasma thereof, thereby removing residual fluorine inside the process container; and a stage (S3) of supplying a gas containing a rare gas into the process container and generating plasma thereof, thereby removing residual hydrogen inside the process container.
    Type: Application
    Filed: September 18, 2007
    Publication date: December 17, 2009
    Applicant: TOKYO ELECTRON LIMITED
    Inventors: Masayuki Kohno, Tatsuo Nishita, Toshio Nakanishi
  • Publication number: 20090239364
    Abstract: Disclosed is a method for forming a gate insulating film comprising an oxidation step wherein a silicon oxide film is formed by having an oxygen-containing plasma act on silicon in the surface of an object to be processed in a processing chamber of a plasma processing apparatus. The processing temperature in the oxidation step is more than 600° C. and not more than 1000° C., and the oxygen-containing plasma is formed by introducing an oxygen-containing processing gas containing at least a rare gas and an oxygen gas into the process chamber while introducing a high frequency wave or microwave into the process chamber through an antenna.
    Type: Application
    Filed: March 28, 2006
    Publication date: September 24, 2009
    Applicant: TOKYO ELECTRON LIMITED
    Inventors: Tatsuo Nishita, Toshio Nakanishi, Shuuichi Ishizuka, Tomoe Nakayama, Yutaka Fujino