Patents by Inventor Kensuke Kasahara

Kensuke Kasahara 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: 12219296
    Abstract: A projection apparatus capable of, when an image input from an external device and an OSD image are rotated by rotation of a projection lens, performing rotation correction suitable for the respective images is provided. A projection apparatus (1) includes a housing; a projection lens (3) that has a holder and that is rotatably attached to the housing; a first rotation position detection unit (70A) and a second rotation position detection unit (70B) that detect rotation states of the holder; a DMD (22B) that outputs, to the projection lens (3), a composite image of a projection image output from an external device and an OSD image including a character output from an internal memory; and a control unit that performs rotation correction on the OSD image and that does not perform rotation correction on the projection image based on detection results of the first rotation position detection unit (70A) and the second rotation position detection unit (70B) when the holder of the projection lens (3) rotates.
    Type: Grant
    Filed: April 29, 2021
    Date of Patent: February 4, 2025
    Assignee: FUJIFILM Corporation
    Inventors: Hitoshi Shimizu, Takeharu Omata, Kensuke Masui, Shoki Kasahara
  • Patent number: 7863648
    Abstract: A field effect transistor (100) exhibiting good performance at high voltage operation and high frequency includes a first field plate electrode (116) and a second field plate electrode (118). The second field plate electrode includes a shielding part (119) located in the region between the first field plate electrode and a drain electrode (114), and serves to shield the first field plate electrode from the drain electrode. When in the cross sectional view in the gate length direction, the length in the gate length direction of an overlap region where the second field plate electrode (118) overlap the upper part of a structure including the first field plate electrode and a gate electrode (113) is designated as Lol, and the gate length is Lg, the relation expressed as 0 ?Lol/Lg?1 holds.
    Type: Grant
    Filed: June 12, 2006
    Date of Patent: January 4, 2011
    Assignee: NEC Corporation
    Inventors: Hironobu Miyamoto, Yuji Ando, Yasuhiro Okamoto, Tatsuo Nakayama, Takashi Inoue, Kazuki Ota, Akio Wakejima, Kensuke Kasahara, Yasuhiro Murase, Kohji Matsunaga, Katsumi Yamanoguchi, Hidenori Shimawaki
  • Patent number: 7800131
    Abstract: A field effect transistor includes a layer structure made of compound semiconductor (111) provided on a semiconductor substrate (110) made of GaAs or InP, as an operation layer, and employs a first field plate electrode (116) and a second field plate electrode (118). The second field plate electrode includes a shielding part (119) located in the region between the first field plate electrode and a drain electrode (114), and serves to shield the first field plate electrode from the drain electrode. When, in the cross sectional view in the gate length direction, the length in the gate length direction of an overlap region, in which the second field plate electrode overlaps the upper part of a structure composed of the first field plate electrode and a gate electrode (113), is designated as Lol, and the gate length is Lg, the relation expressed as 0?Lol/Lg?1 holds.
    Type: Grant
    Filed: June 12, 2006
    Date of Patent: September 21, 2010
    Assignee: NEC Corporation
    Inventors: Hironobu Miyamoto, Yuji Ando, Yasuhiro Okamoto, Tatsuo Nakayama, Takashi Inoue, Kazuki Ota, Akio Wakejima, Kensuke Kasahara, Yasuhiro Murase, Kohji Matsunaga, Katsumi Yamanoguchi, Hidenori Shimawaki
  • Publication number: 20090230430
    Abstract: A field effect transistor includes a layer structure made of compound semiconductor (111) provided on a semiconductor substrate (110) made of GaAs or InP, as an operation layer, and employs a first field plate electrode (116) and a second field plate electrode (118). The second field plate electrode includes a shielding part (119) located in the region between the first field plate electrode and a drain electrode (114), and serves to shield the first field plate electrode from the drain electrode. When, in the cross sectional view in the gate length direction, the length in the gate length direction of an overlap region, in which the second field plate electrode overlaps the upper part of a structure composed of the first field plate electrode and a gate electrode (113), is designated as Lol, and the gate length is Lg, the relation expressed as 0?Lol/Lg?1 holds.
    Type: Application
    Filed: June 12, 2006
    Publication date: September 17, 2009
    Applicant: NEC CORPRORATION
    Inventors: Hironobu Miyamoto, Yuji Ando, Yasuhiro Okamoto, Tatsuo Nakayama, Takashi Inoue, Kazuki Ota, Aklo Wakejima, Kensuke Kasahara, Yasuhiro Murase, Kohji Matsunaga, Katsumi Yamanoguchi, Hidenori Shimawaki
  • Publication number: 20090230429
    Abstract: A field effect transistor (100) exhibiting good performance at high voltage operation and high frequency includes a first field plate electrode (116) and a second field plate electrode (118). The second field plate electrode includes a shielding part (119) located in the region between the first field plate electrode and a drain electrode (114), and serves to shield the first field plate electrode from the drain electrode. When in the cross sectional view in the gate length direction, the length in the gate length direction of an overlap region where the second field plate electrode (118) overlap the upper part of a structure including the first field plate electrode and a gate electrode (113) is designated as Lol, and the gate length is Lg, the relation expressed as 0?Lol/Lg?1 holds.
    Type: Application
    Filed: June 12, 2006
    Publication date: September 17, 2009
    Applicant: NEC CORPORATION
    Inventors: Hironobu Miyamoto, Yuji Ando, Yasuhiro Okamoto, Tasuo Nakayama, Takashi Inoue, Kazuki Ota, Akio Wakejima, Kensuke Kasahara, Yasuhiro Murase, Kohji Matsunaga, Katsumi Yamanoguchi, Hidenori Shimawaki
  • Patent number: 7071526
    Abstract: A GaN semiconductor device with improved heat resistance of the Schottky junction electrode and excellent power performance and reliability is provided. In this semiconductor device having a Schottky gate electrode 17 which is in contact with an AlGaN electron supplying layer 14, a gate electrode 17 comprises a laminated structure wherein a first metal layer 171 formed of any of Ni, Pt and Pd, a second metal layer 172 formed of any of Mo, Pt, W, Ti, Ta, MoSi, PtSi, WSi, TiSi, TaSi, MoN, WN, TiN and TaN, and a third metal layer formed of any of Au, Cu, Al and Pt. Since the second metal layer comprises a metal material having a high melting point, it works as a barrier to the interdiffusion between the first metal layer and the third metal layer, and the deterioration of the gate characteristics caused by high temperature operation is suppressed.
    Type: Grant
    Filed: June 17, 2003
    Date of Patent: July 4, 2006
    Assignee: NEC Corporation
    Inventors: Yuji Ando, Hironobu Miyamoto, Yasuhiro Okamoto, Kensuke Kasahara, Tatsuo Nakayama, Masaaki Kuzuhara
  • Publication number: 20060054929
    Abstract: A semiconductor device includes, on a substrate (101), a buffer layer (102), and an channel layer (104), consisting essentially of semiconductor of a wultzite compound of group III-V, having a (0001) plane as a principal plane. The channel layer is subjected to compressive strain. A carrier supplying layer (103) is interposed between the channel layer (104) and the buffer layer (102). The carrier supplying layer (103) consists essentially of semiconductor of a wultzite compound of group III-V as a main component. N-type impurities are doped into the entire or part of the carrier supplying layer (103).
    Type: Application
    Filed: November 29, 2004
    Publication date: March 16, 2006
    Inventors: Tatsuo Nakayama, Yuji Ando, Hironobu Miyamoto, Kensuke Kasahara, Yasuhiro Okamoto, Masaaki Kuzuhara
  • Publication number: 20050151255
    Abstract: A GaN semiconductor device with improved heat resistance of the Schottky junction electrode and excellent power performance and reliability is provided. In this semiconductor device having a Schottky gate electrode 17 which is in contact with an AlGaN electron supplying layer 14, a gate electrode 17 comprises a laminated structure wherein a first metal layer 171 formed of any of Ni, Pt and Pd, a second metal layer 172 formed of any of Mo, Pt, W, Ti, Ta, MoSi, PtSi, WSi, TiSi, TaSi, MoN, WN, TiN and TaN, and a third metal layer formed of any of Au, Cu, Al and Pt. Since the second metal layer comprises a metal material having a high melting point, it works as a barrier to the interdiffusion between the first metal layer and the third metal layer, and the deterioration of the gate characteristics caused by high temperature operation is suppressed.
    Type: Application
    Filed: June 17, 2003
    Publication date: July 14, 2005
    Inventors: Yuji Ando, Hironobu Miyamoto, Yasuhiro Okamoto, Kensuke Kasahara, Tatsuo Nakayama, Masaaki Kuzuhara
  • Patent number: 6765241
    Abstract: A group III nitride semiconductor device of field effect transistor type having improved productivity, reduced parasitic capacitances adapted for excellent device performance in high-speed operation as well as good heat diffusion characteristics. The device includes an epitaxial growth layer of a group III nitride semiconductor with a buffer layer laid under it, formed on an A plane (an (11-20) plane) of a sapphire. Thereon a gate electrode, a source electrode, a drain electrode, and pad electrodes are formed, and a ground conductor layer is formed on the back face of the sapphire substrate. A thickness of said sapphire substrate tsub satisfies the following Equation (1).
    Type: Grant
    Filed: February 27, 2003
    Date of Patent: July 20, 2004
    Assignee: NEC Corporation
    Inventors: Yasuo Ohno, Nobuyuki Hayama, Kensuke Kasahara, Tatsuo Nakayama, Hironobu Miyamoto, Yuji Takahashi, Yuji Ando, Kohji Matsunaga, Masaaki Kuzuhara
  • Publication number: 20030151064
    Abstract: An object of the present invention is to improve, in a group III nitride semiconductor device, the productivity, the heat diffusion characteristic and the device performance in high-speed operation, and, therefor, in a group III nitride semiconductor device of the present invention, an epitaxial growth layer 13 of a group III nitride semiconductor with a buffer layer 12 laid under it is formed on a sapphire substrate 11 in which an A plane (an (11-20) plane) is set to be the principal plane, and thereon a gate electrode 16, a source electrode 15 and a drain electrode 17 are formed, wherein a thickness of the single crystalline sapphire substrate is specifically set to be 100 &mgr;m or less.
    Type: Application
    Filed: February 27, 2003
    Publication date: August 14, 2003
    Inventors: Yasuo Ohno, Nobuyuki Hayama, Kensuke Kasahara, Tatsuo Nakayama, Hironobu Miyamoto, Yuji Takahashi, Yuji Ando, Kohji Matsunaga, Masaaki Kuzuhara
  • Patent number: 6552373
    Abstract: A hetero-junction FET has an intermediate layer including n-type-impurity doped layer between an electron supply layer and an n-type cap layer. The intermediate layer cancels the polarized negative charge generated between the electron supply layer and the n-type cap layer by ionized positive charge, thereby reducing the barrier against the electrons and source/drain resistance.
    Type: Grant
    Filed: March 28, 2001
    Date of Patent: April 22, 2003
    Assignee: NEC Corporation
    Inventors: Yuji Ando, Hironobu Miyamoto, Naotaka Iwata, Koji Matsunaga, Masaaki Kuzuhara, Kensuke Kasahara, Kazuaki Kunihiro, Yuji Takahashi, Tatsuo Nakayama, Nobuyuki Hayama, Yasuo Ohno
  • Patent number: 6492669
    Abstract: A carrier travel layer is formed on the substrate of a semiconductor device with a buffer layer interposed, and a spacer layer and carrier supply layer are then formed on this carrier travel layer. On the carrier supply layer are provided a source electrode and a drain electrode, and a gate electrode is provided on an interposed Schottky layer. The carrier supply layer is composed of AlGaN and has tensile strain. The Schottky layer is composed of InGaN and has compressive strain. A negative piezoelectric charge is induced on the carrier supply layer side of the Schottky layer, and a positive piezoelectric charge is induced on the opposite side of the Schottky layer, whereby a sufficient Schottky barrier height is obtained and leakage current is suppressed.
    Type: Grant
    Filed: June 28, 2001
    Date of Patent: December 10, 2002
    Assignee: NEC Corporation
    Inventors: Tatsuo Nakayama, Yuji Ando, Hironobu Miyamoto, Kazuaki Kunihiro, Yuji Takahashi, Kensuke Kasahara, Nobuyuki Hayama, Yasuo Ohno, Kouji Matsunaga, Masaaki Kuzuhara
  • Patent number: 6476431
    Abstract: A p-type layer and an n-type layer which constitute a barrier layer are provided, and a leak of the holes at the time of the negative bias accompanying the p-type layer buffer required for the higher tolerance voltage is suppressed, and the discharge of the holes at the positive bias can be efficiently carried out. The tolerance voltage at the time of the OFF state is raised at the p-type layer buffer, and the tolerance voltage at the time of the ON state at the discharge of the holes is raised. Since no leak is generated from the p-type layer, the drain current is not lowered, and a higher output can be realized both in terms of the current and in terms of the voltage.
    Type: Grant
    Filed: November 12, 1999
    Date of Patent: November 5, 2002
    Assignee: NEC Corporation
    Inventors: Yasuo Ohno, Kensuke Kasahara, Kazuaki Kunihiro, Yuji Takahashi
  • Patent number: 6465814
    Abstract: A semiconductor device of the present invention comprises Al0.3Ga0.7N layer 4 and Al0.1Ga0.9N layer 5 having different Al contents as an electron supply layer on GaN layer 6 serving as an active layer. An area where Al0.3Ga0.7N layer 4 is formed is used as a low resistance area, while an area where Al0.1Ga0.9N layer 5 is formed is used as a high resistance area. As a result, a distribution of two-dimensional electrons serving as carriers is produced within a horizontal plane perpendicular to the thickness direction of the layers to form a desired device configuration. For example, when the configuration is applied to a transistor configuration, a channel concentration under a gate is reduced to improve withstand voltage between the gate and a drain, and at the same time, a channel concentration in source and drain areas is increased to realize low contact resistance.
    Type: Grant
    Filed: June 27, 2001
    Date of Patent: October 15, 2002
    Assignee: NEC Corporation
    Inventors: Kensuke Kasahara, Yasuo Ohno, Masaaki Kuzuhara, Hironobu Miyamoto, Yuji Ando, Tatsuo Nakayama, Kazuaki Kunihiro, Nobuyuki Hayama, Yuji Takahashi, Kouji Matsunaga
  • Patent number: 6441391
    Abstract: An object of the present invention is to improve, in a group III nitride semiconductor device, the productivity, heat radiation characteristic and performance in the element high speed operation; upon a sapphire substrate in which an A plane (an (11-20) plane) is set to be the basal plane, an epitaxial growth layer of a group III nitride semiconductor is formed and, thereon, a gate electrode 16, a source electrode 15 and a drain electrode 17 are formed; these electrodes are disposed in such a way that a direction along which they are laid makes an angle within 20° with respect to a C axis of sapphire.
    Type: Grant
    Filed: August 29, 2001
    Date of Patent: August 27, 2002
    Assignee: NEC Corporation
    Inventors: Yasuo Ohno, Nobuyuki Hayama, Kensuke Kasahara, Tatsuo Nakayama, Hironobu Miyamoto, Yuji Takahashi, Yuji Ando, Kohji Matsunaga, Masaaki Kuzuhara
  • Patent number: 6440822
    Abstract: In a method of manufacturing a semiconductor device, trench sections are formed on a side of one of opposing surface portions of a substrate. At lest a part of each of the trench sections is covered by a power supply metal layer which is formed on the one surface portion of the substrate. The substrate is fixed to a support such that the one surface of the substrate fits to the support. A chip is separated from the substrate using the trench sections. A conductive film is formed on side surface portions of the chip and the other surface portion of the chip. Then, the chip is separated from the support.
    Type: Grant
    Filed: July 9, 2001
    Date of Patent: August 27, 2002
    Assignee: NEC Corporation
    Inventors: Nobuyuki Hayama, Masaaki Kuzuhara, Kouji Matsunaga, Tatsuo Nakayama, Yuji Takahashi, Yasuo Ohno, Kazuaki Kunihiro, Kensuke Kasahara, Hironobu Miyamoto, Yuji Ando
  • Publication number: 20020048889
    Abstract: In a method of manufacturing a semiconductor device, trench sections are formed on a side of one of opposing surface portions of a substrate. At least a part of each of the trench sections is covered by a power supply metal layer which is formed on the one surface portion of the substrate. The substrate is fixed to a support such that the one surface of the substrate fits to the support. A chip is separated from the substrate using the trench sections. A conductive film is formed on side surface portions of the chip and the other surface portion of the chip. Then, the chip is separated from the support.
    Type: Application
    Filed: July 9, 2001
    Publication date: April 25, 2002
    Applicant: NEC Corporation
    Inventors: Nobuyuki Hayama, Masaaki Kuzuhara, Kouji Matsunaga, Tatsuo Nakayama, Yuji Takahashi, Yasuo Ohno, Kazuaki Kunihiro, Kensuke Kasahara, Hironobu Miyamoto, Yuji Ando
  • Publication number: 20020047113
    Abstract: An object of the present invention is to improve, in a group III nitride semiconductor device, the productivity, heat radiation characteristic and performance in the element high speed operation; upon a sapphire substrate in which an A plane (an (11-20) plane) is set to be the basal plane, an epitaxial growth layer of a group III nitride semiconductor is formed and, thereon, a gate electrode 16, a source electrode 15 and a drain electrode 17 are formed; these electrodes are disposed in such a way that a direction along which they are laid makes an angle within 20° with respect to a C axis of sapphire.
    Type: Application
    Filed: August 29, 2001
    Publication date: April 25, 2002
    Applicant: NEC CORPORATION
    Inventors: Yasuo Ohno, Nobuyuki Hayama, Kensuke Kasahara, Tatsuo Nakayama, Hironobu Miyamoto, Yuji Takahashi, Yuji Ando, kohji Matsunaga, Masaaki Kuzuhara
  • Publication number: 20020017696
    Abstract: A carrier travel layer is formed on the substrate of a semiconductor device with a buffer layer interposed, and a spacer layer and carrier supply layer are then formed on this carrier travel layer. On the carrier supply layer are provided a source electrode and a drain electrode, and a gate electrode is provided on an interposed Schottky layer. The carrier supply layer is composed of AlGaN and has tensile strain. The Schottky layer is composed of InGaN and has compressive strain. A negative piezoelectric charge is induced on the carrier supply layer side of the Schottky layer, and a positive piezoelectric charge is induced on the opposite side of the Schottky layer, whereby a sufficient Schottky barrier height is obtained and leakage current is suppressed.
    Type: Application
    Filed: June 28, 2001
    Publication date: February 14, 2002
    Inventors: Tatsuo Nakayama, Yuji Ando, Hironobu Miyamoto, Kazuaki Kunihiro, Yuji Takahashi, Kensuke Kasahara, Nobuyuki Hayama, Yasuo Ohno, Kouji Matsunaga, Masaaki Kuzuhara
  • Publication number: 20020017648
    Abstract: A semiconductor device of the present invention comprises Al0.3Ga0.7N layer 4 and Al0.1Ga0.9N layer 5 having different Al contents as an electron supply layer on GaN layer 6 serving as an active layer. An area where Al0.3Ga0.7N layer 4 is formed is used as a low resistance area, while an area where Al0.1Ga0.9N layer 5 is formed is used as a high resistance area. As a result, a distribution of two-dimensional electrons serving as carriers is produced within a horizontal plane perpendicular to the thickness direction of the layers to form a desired device configuration. For example, when the configuration is applied to a transistor configuration, a channel concentration under a gate is reduced to improve withstand voltage between the gate and a drain, and at the same time, a channel concentration in source and drain areas is increased to realize low contact resistance.
    Type: Application
    Filed: June 27, 2001
    Publication date: February 14, 2002
    Inventors: Kensuke Kasahara, Yasuo Ohno, Masaaki Kuzuhara, Hironobu Miyamoto, Yuji Ando, Tatsuo Nakayama, Kazuaki Kunihiro, Nobuyuki Hayama, Yuji Takahashi, Kouji Matsunaga