Patents by Inventor Kenji Imanishi

Kenji Imanishi 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: 20130256683
    Abstract: An embodiment of a compound semiconductor device includes: a substrate; an electron transport layer and an electron supply layer formed over the substrate; a gate electrode, a source electrode and a drain electrode formed over the electron supply layer; a p-type semiconductor layer formed between the electron supply layer and the gate electrode; and a hole canceling layer formed between the electron supply layer and the p-type semiconductor layer, the hole canceling layer containing a donor or a recombination center and canceling a hole.
    Type: Application
    Filed: December 21, 2012
    Publication date: October 3, 2013
    Applicant: FUJITSU LIMITED
    Inventor: Kenji IMANISHI
  • Publication number: 20130248872
    Abstract: A semiconductor device includes: a nucleation layer formed over a substrate; a buffer layer formed over the nucleation layer; a first nitride semiconductor layer formed over the buffer layer; and a second nitride semiconductor layer formed over the first nitride semiconductor layer, wherein the ratio of yellow luminescence emission to band edge emission in photoluminescence is 400% or less and the twist value in an X-ray rocking curve is 1,000 arcsec or less.
    Type: Application
    Filed: February 8, 2013
    Publication date: September 26, 2013
    Applicant: FUJITSU LIMITED
    Inventors: Norikazu NAKAMURA, Atsushi YAMADA, Tetsuro ISHIGURO, Toyoo MIYAJIMA, Kenji IMANISHI
  • Patent number: 8507329
    Abstract: A compound semiconductor device is provided with a substrate, an AlN layer formed over the substrate, an AlGaN layer formed over the AlN layer and larger in electron affinity than the AlN layer, another AlGaN layer formed over the AlGaN layer and smaller in electron affinity than the AlGaN layer. Furthermore, there are provided an i-GaN layer formed over the latter AlGaN layer, and an i-AlGaN layer and an n-AlGaN layer formed over the i-GaN layer.
    Type: Grant
    Filed: August 22, 2012
    Date of Patent: August 13, 2013
    Assignee: Fujitsu Limited
    Inventors: Toshihide Kikkawa, Kenji Imanishi
  • Patent number: 8466674
    Abstract: A magnetic testing apparatus has a magnetizing device applying a rotating magnetic field to a material to be tested, a testing signal detecting device, and a signal processing device applying signal processing to the testing signal. The signal processing device has a first synchronous detecting device detecting a testing signal by using the first current as a reference signal, a second synchronous detecting device detecting an output signal of the first synchronous detecting device by using the second current as a reference signal to extract a candidate flaw signal, and a testing image display device displaying a testing image in which each of pixels has a gray level corresponding to an intensity of the candidate flaw signal at each of positions of the material to be tested, and a phase of the candidate flaw signal at each of the positions is capable of being identified.
    Type: Grant
    Filed: May 14, 2009
    Date of Patent: June 18, 2013
    Assignee: Nippon Steel & Sumitomo Metal Corporation
    Inventors: Toshiyuki Suzuma, Kenji Imanishi
  • Publication number: 20130139950
    Abstract: A rotational misalignment between semiconductor wafers constituting a bonded wafer is calculated. A light source is arranged at a position which is on a front side of an opening of a notch and which is separated from an outer edge portion of a bonded wafer by a predetermined interval, and outputs light to irradiate the outer edge portion of the bonded wafer including the notch. A camera receives and photoelectrically converts reflected light that is specularly-reflected by the outer edge portion of the bonded wafer including the notch among the light outputted by the light source in order to output a brightness distribution of the reflected light as an image. A computer analyzes positions of notches from the image outputted by the camera to obtain a notch position misalignment, and further calculates a rotational misalignment between semiconductor wafers using a center position misalignment between the semiconductor wafers.
    Type: Application
    Filed: November 30, 2012
    Publication date: June 6, 2013
    Applicants: Kobelco Research Institute, Inc., Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.)
    Inventors: Masato KANNAKA, Masakazu Kajita, Eiji Takahashi, Yuji Yamamoto, Masaru Akamatsu, Kunio Iba, Kenji Imanishi
  • Patent number: 8440549
    Abstract: A semiconductor epitaxial substrate includes: a single crystal substrate; an AlN layer epitaxially grown on the single crystal substrate; and a nitride semiconductor layer epitaxially grown on the AlN layer, wherein an interface between the AlN layer and nitride semiconductor layer has a larger roughness than an interface between the single crystal substrate and AlN layer, and a skewness of the upper surface of the AlN layer is positive.
    Type: Grant
    Filed: September 20, 2011
    Date of Patent: May 14, 2013
    Assignees: Fujitsu Limited, Hitachi Cable Co., Ltd.
    Inventors: Kenji Imanishi, Toshihide Kikkawa, Takeshi Tanaka, Yoshihiko Moriya, Yohei Otoki
  • Patent number: 8426260
    Abstract: A compound semiconductor device includes: an electron transport layer formed over a substrate; an electron supply layer formed over the electron transport layer; and a cap layer formed over the electron supply layer; the cap layer includes a first compound semiconductor layer containing GaN; a second compound semiconductor layer containing AlN, which is formed over the first compound semiconductor layer; a third compound semiconductor layer containing GaN, which is formed over the second compound semiconductor layer; and at least one of a first AlGaN-containing layer and a second AlGaN-containing layer, with the first AlGaN-containing layer formed between the first compound semiconductor layer and the second compound semiconductor layer and the Al content increases toward the second compound semiconductor layer, and the second AlGaN-containing layer formed between the second compound semiconductor layer and the third compound semiconductor layer and the Al content increases toward the second compound semicond
    Type: Grant
    Filed: November 11, 2011
    Date of Patent: April 23, 2013
    Assignee: Fujitsu Limited
    Inventors: Toyoo Miyajima, Toshihide Kikkawa, Kenji Imanishi, Toshihiro Ohki, Masahito Kanamura
  • Patent number: 8426892
    Abstract: A compound semiconductor device has a buffer layer formed on a conductive SiC substrate, an AlxGa1-xN layer formed on the buffer layer in which an impurity for reducing carrier concentration from an unintentionally doped donor impurity is added and in which the Al composition x is 0<x<1, a GaN-based carrier transit layer formed on the AlxGa1-xN layer, a carrier supply layer formed on the carrier transit layer, a source electrode and a drain electrode formed on the carrier supply layer, and a gate electrode formed on the carrier supply layer between the source electrode and the drain electrode. Therefore, a GaN-HEMT that is superior in device characteristics can be realized in the case of using a relatively less expensive conductive SiC substrate compared with a semi-insulating SiC substrate.
    Type: Grant
    Filed: February 20, 2008
    Date of Patent: April 23, 2013
    Assignee: Fujitsu Limited
    Inventors: Kenji Imanishi, Toshihide Kikkawa
  • Publication number: 20130082360
    Abstract: A compound semiconductor multilayer structure is formed on a Si substrate. The compound semiconductor multilayer structure includes an electrode transit layer, an electrode donor layer formed above the electron transit layer, and a cap layer formed above the electron donor layer. The cap layer contains a first crystal polarized in the same direction as the electron transit layer and the electron donor layer and a second crystal polarized in the direction opposite to the polarization direction of the electron transit layer and the electron donor layer.
    Type: Application
    Filed: July 18, 2012
    Publication date: April 4, 2013
    Applicant: FUJITSU LIMITED
    Inventors: Toyoo MIYAJIMA, Kenji IMANISHI, Atsushi YAMADA, Norikazu NAKAMURA
  • Publication number: 20130076442
    Abstract: An embodiment of a compound semiconductor device includes: a substrate; a compound semiconductor stacked structure formed over the substrate; and an amorphous insulating film formed between the substrate and the compound semiconductor stacked structure.
    Type: Application
    Filed: July 10, 2012
    Publication date: March 28, 2013
    Applicant: FUJITSU LIMITED
    Inventors: Norikazu Nakamura, Atsushi Yamada, Shiro Ozaki, Kenji Imanishi
  • Publication number: 20130075751
    Abstract: An embodiment of a compound semiconductor device includes: a substrate; an electron channel layer and an electron supply layer formed over the substrate; a gate electrode, a source electrode and a drain electrode formed on or above the electron supply layer; a p-type semiconductor layer formed between the electron supply layer and the gate electrode; and a hole barrier layer formed between the electron supply layer and the p-type semiconductor layer, a band gap of the hole barrier layer being larger than that of the electron supply layer.
    Type: Application
    Filed: August 15, 2012
    Publication date: March 28, 2013
    Applicant: Fujitsu Limited
    Inventor: Kenji IMANISHI
  • Publication number: 20120320642
    Abstract: A compound semiconductor device includes a substrate; and a compound semiconductor multilayer structure which is formed above the substrate and which contains compound semiconductors containing Group III elements, wherein the compound semiconductor multilayer structure has a thickness of 10 ?m or less and a percentage of aluminum atoms is 50% or more of the number of atoms of the Group III elements.
    Type: Application
    Filed: May 11, 2012
    Publication date: December 20, 2012
    Applicant: FUJITSU LIMITED
    Inventor: Kenji IMANISHI
  • Publication number: 20120315743
    Abstract: A compound semiconductor device is provided with a substrate, an AlN layer formed over the substrate, an AlGaN layer formed over the AlN layer and larger in electron affinity than the AlN layer, another AlGaN layer formed over the AlGaN layer and smaller in electron affinity than the AlGaN layer. Furthermore, there are provided an i-GaN layer formed over the latter AlGaN layer, and an i-AlGaN layer and an n-AlGaN layer formed over the i-GaN layer.
    Type: Application
    Filed: August 22, 2012
    Publication date: December 13, 2012
    Applicant: FUJITSU LIMITED
    Inventors: Toshihide KIKKAWA, Kenji IMANISHI
  • Patent number: 8294181
    Abstract: A compound semiconductor device is provided with a substrate, an AlN layer formed over the substrate, an AlGaN layer formed over the AlN layer and larger in electron affinity than the AlN layer, another AlGaN layer formed over the AlGaN layer and smaller in electron affinity than the AlGaN layer. Furthermore, there are provided an i-GaN layer formed over the latter AlGaN layer, and an i-AlGaN layer and an n-AlGaN layer formed over the i-GaN layer.
    Type: Grant
    Filed: February 1, 2010
    Date of Patent: October 23, 2012
    Assignee: Fujitsu Limited
    Inventors: Toshihide Kikkawa, Kenji Imanishi
  • Patent number: 8264006
    Abstract: A semiconductor epitaxial substrate includes: a single crystal substrate; an AlN layer epitaxially grown on the single crystal substrate; and a nitride semiconductor layer epitaxially grown on the AlN layer, wherein an interface between the AlN layer and nitride semiconductor layer has a larger roughness than an interface between the single crystal substrate and AlN layer, and a skewness of the upper surface of the AlN layer is positive.
    Type: Grant
    Filed: May 3, 2010
    Date of Patent: September 11, 2012
    Assignees: Fujitsu Limited, Hitachi Cable Co., Ltd.
    Inventors: Kenji Imanishi, Toshihide Kikkawa, Takeshi Tanaka, Yoshihiko Moriya, Yohei Otoki
  • Patent number: 8264005
    Abstract: A semiconductor epitaxial substrate includes: a single crystal substrate; an AlN layer epitaxially grown on the single crystal substrate; and a nitride semiconductor layer epitaxially grown on the AlN layer, wherein an interface between the AlN layer and nitride semiconductor layer has a larger roughness than an interface between the single crystal substrate and AlN layer, and a skewness of the upper surface of the AlN layer is positive.
    Type: Grant
    Filed: May 3, 2010
    Date of Patent: September 11, 2012
    Assignee: Fujitsu Limited
    Inventors: Kenji Imanishi, Toshihide Kikkawa, Takeshi Tanaka, Yoshihiko Moriya, Yohei Otoki
  • Publication number: 20120208351
    Abstract: A cleaning apparatus for a semiconductor manufacturing apparatus includes: a oxide removal unit that removes an oxide over a surface of a deposit adhered to components of the semiconductor manufacturing apparatus, and a deposit removal unit that removes the deposit after the oxide over the surface is removed by the oxide removal unit.
    Type: Application
    Filed: January 25, 2012
    Publication date: August 16, 2012
    Applicant: FUJITSU LIMITED
    Inventors: Norikazu Nakamura, Atsushi Yamada, Masayuki Takeda, Keiji Watanabe, Kenji Imanishi
  • Publication number: 20120205662
    Abstract: A semiconductor device includes: a semiconductor layer formed over a substrate; an insulating film formed over the semiconductor layer; and an electrode formed over the insulating film, wherein the insulating film includes an amorphous film including carbon.
    Type: Application
    Filed: January 25, 2012
    Publication date: August 16, 2012
    Applicant: FUJITSU LIMITED
    Inventors: Norikazu Nakamura, Shirou Ozaki, Masayuki Takeda, Toyoo Miyajima, Toshihiro Ohki, Masahito Kanamura, Kenji Imanishi, Toshihide Kikkawa, Keiji Watanabe
  • Publication number: 20120138944
    Abstract: A compound semiconductor device includes: a compound semiconductor layer; a first film formed over the compound semiconductor layer, the first film being in a negatively charged state or a non-charged state at an interface with the compound semiconductor layer; a second film formed over the first film, the second film being in a positively charged state at an interface with the first film; and a gate electrode to be embedded in an opening formed in the second film.
    Type: Application
    Filed: November 11, 2011
    Publication date: June 7, 2012
    Applicant: FUJITSU LIMITED
    Inventors: Masahito KANAMURA, Toshihide KIKKAWA, Kenji IMANISHI
  • Publication number: 20120138956
    Abstract: A compound semiconductor device includes: a substrate; an electron transit layer formed over the substrate; an electron supply layer formed over the electron transit layer; and a buffer layer formed between the substrate and the electron transit layer and including AlxGa1-xN(0?x?1), wherein the x value represents a plurality of maximums and a plurality of minimums in the direction of the thickness of the buffer layer, and the variation of x in any area having a 1 nm thickness in the buffer layer is 0.5 or less.
    Type: Application
    Filed: November 21, 2011
    Publication date: June 7, 2012
    Applicant: FUJITSU LIMITED
    Inventors: Sanae SHIMIZU, Kenji Imanishi, Atsushi Yamada, Toyoo Miyajima