Patents by Inventor Tomoyoshi Kushida

Tomoyoshi Kushida 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: 10680091
    Abstract: In a semiconductor device having a heterojunction type superjunction structure, a drain portion and a source portion are electrically connected to one of a two-dimensional electron gas layer and a two-dimensional hole gas layer, and a gate portion is prevented by an insulating region from directly contacting the one of the two-dimensional election gas layer and the two-dimensional hole gas layer.
    Type: Grant
    Filed: December 21, 2018
    Date of Patent: June 9, 2020
    Assignees: Toyota Jidosha Kabushiki Kaisha, Toyota School Foundation
    Inventors: Tomoyoshi Kushida, Yoshitaka Nagasato, Naotaka Iwata, Hiroyuki Sakaki
  • Publication number: 20190198652
    Abstract: In a semiconductor device having a heterojunction type superjunction structure, a drain portion and a source portion are electrically connected to one of a two-dimensional electron gas layer and a two-dimensional hole gas layer, and a gate portion is prevented by an insulating region from directly contacting the one of the two-dimensional election gas layer and the two-dimensional hole gas layer.
    Type: Application
    Filed: December 21, 2018
    Publication date: June 27, 2019
    Applicants: Toyota Jidosha Kabushiki Kaisha, Toyota School Foundation
    Inventors: Tomoyoshi Kushida, Yoshitaka Nagasato, Naotaka Iwata, Hiroyuki Sakaki
  • Patent number: 9653621
    Abstract: A semiconductor apparatus (10) includes: a layered structure (100) that includes double junction structures that have a first junction (151, 153) where a wide-bandgap layer (102, 104) and a narrow-bandgap layer (101, 103, 105) are layered on each other and a second junction (152, 154) where a narrow-bandgap layer (101, 103, 105) and a wide-bandgap layer (102, 104) are layered on each other, and electrode semiconductor layers (110, 120) are joined to each layer of the layered structure. Each double junction structure includes a pair of a first region (131, 133) that has negative fixed charge and a second region (132, 134) that has positive fixed charge. The first region is closer to the first junction than to a center of the wide-bandgap layer. The second region is closer to the second junction than to the center of the wide-bandgap layer. A 2DEG or a 2DHG is formed at each junction. The semiconductor apparatus functions as an electric energy storage device such as a capacitor.
    Type: Grant
    Filed: March 14, 2013
    Date of Patent: May 16, 2017
    Assignees: TOYOTA JIDOSHA KABUSHIKI KAISHA, TOYOTA SCHOOL FOUNDATION
    Inventors: Tomoyoshi Kushida, Hiroyuki Sakaki, Masato Ohmori
  • Publication number: 20150108609
    Abstract: A semiconductor apparatus (10) includes: a layered structure (100) that includes double junction structures that have a first junction (151, 153) where a wide-bandgap layer (102, 104) and a narrow-bandgap layer (101, 103, 105) are layered on each other and a second junction (152, 154) where a narrow-bandgap layer (101, 103, 105) and a wide-bandgap layer (102, 104) are layered on each other, and electrode semiconductor layers (110, 120) are joined to each layer of the layered structure. Each double junction structure includes a pair of a first region (131, 133) that has negative fixed charge and a second region (132, 134) that has positive fixed charge. The first region is closer to the first junction than to a center of the wide-bandgap layer. The second region is closer to the second junction than to the center of the wide-bandgap layer. A 2DEG or a 2DHG is formed at each junction. The semiconductor apparatus functions as an electric energy storage device such as a capacitor.
    Type: Application
    Filed: March 14, 2013
    Publication date: April 23, 2015
    Applicants: TOYOTA SCHOOL FOUNDATION, TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Tomoyoshi Kushida, Hiroyuki Sakaki, Masato Ohmori
  • Patent number: 8830114
    Abstract: A mobile object detecting apparatus includes first radiation detecting means; and second radiation detecting means for radiating an electromagnetic wave having the same frequency as the electromagnetic wave radiated by the first radiation detecting means such that the radiated electromagnetic wave passes near a point in the first radiation detecting means from which the electromagnetic wave is radiated, and detecting a standing wave which is generated due to reflection of the radiated electromagnetic wave at an object; wherein a distance, over which the electromagnetic wave radiated by the first radiation detecting means travels until it reaches near the first radiation detecting means, corresponds to a distance of an integral multiple of a wave length of a half cycle of the electromagnetic waves radiated by the radiation detecting means plus a wave length of a predetermined period which is smaller than the half cycle.
    Type: Grant
    Filed: September 30, 2010
    Date of Patent: September 9, 2014
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventors: Tomoyoshi Yasue, Tomoyoshi Kushida
  • Publication number: 20120235850
    Abstract: A mobile object detecting apparatus includes first radiation detecting means ; and second radiation detecting means for radiating an electromagnetic wave having the same frequency as the electromagnetic wave radiated by the first radiation detecting means such that the radiated electromagnetic wave passes near a point in the first radiation detecting means from which the electromagnetic wave is radiated, and detecting a standing wave which is generated due to reflection of the radiated electromagnetic wave at an object; wherein a distance, over which the electromagnetic wave radiated by the first radiation detecting means travels until it reaches near the first radiation detecting means, corresponds to a distance of an integral multiple of a wave length of a half cycle of the electromagnetic waves radiated by the radiation detecting means plus a wave length of a predetermined period which is smaller than the half cycle.
    Type: Application
    Filed: September 30, 2010
    Publication date: September 20, 2012
    Inventors: Tomoyoshi Yasue, Tomoyoshi Kushida
  • Patent number: 7569914
    Abstract: With conventional device, the quantity of complex defects differs with each semiconductor device because the concentration of impurities intrinsically contained differs for each silicon wafer. Consequently, there is an undesirable variation in characteristics among the semiconductor devices. The invention provides a method for manufacturing PIN type diode which comprises an intermediate semiconductor region in which complex defects are formed. The method comprises introducing impurities (for example, carbon), which are the same kind of impurities intrinsically contained in the intermediate semiconductor region, into the intermediate semiconductor region, and irradiating the intermediate semiconductor region with helium ions to form point defects.
    Type: Grant
    Filed: September 27, 2007
    Date of Patent: August 4, 2009
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventors: Shinya Yamazaki, Tomoyoshi Kushida, Takahide Sugiyama
  • Patent number: 7507646
    Abstract: With conventional device, the quantity of complex defects differs with each semiconductor device because the concentration of impurities intrinsically contained differs for each silicon wafer. Consequently, there is an undesirable variation in characteristics among the semiconductor devices. The invention provides a method for manufacturing PIN type diode which comprises an intermediate semiconductor region in which complex defects are formed. The method comprises introducing impurities (for example, carbon), which are the sane kind of impurities intrinsically contained in the intermediate semiconductor region, into the intermediate semiconductor region, and irradiating the intermediate semiconductor region with helium ions to form point defects.
    Type: Grant
    Filed: May 19, 2006
    Date of Patent: March 24, 2009
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventors: Shinya Yamazaki, Tomoyoshi Kushida, Takahide Sugiyama
  • Publication number: 20080023795
    Abstract: With conventional device, the quantity of complex defects differs with each semiconductor device because the concentration of impurities intrinsically contained differs for each silicon wafer. Consequently, there is an undesirable variation in characteristics among the semiconductor devices. The invention provides a method for manufacturing PIN type diode which comprises an intermediate semiconductor region in which complex defects are formed. The method comprises introducing impurities (for example, carbon), which are the same kind of impurities intrinsically contained in the intermediate semiconductor region, into the intermediate semiconductor region, and irradiating the intermediate semiconductor region with helium ions to form point defects.
    Type: Application
    Filed: September 27, 2007
    Publication date: January 31, 2008
    Inventors: Shinya YAMAZAKI, Tomoyoshi KUSHIDA, Takahide SUGIYAMA
  • Publication number: 20060281263
    Abstract: With conventional device, the quantity of complex defects differs with each semiconductor device because the concentration of impurities intrinsically contained differs for each silicon wafer. Consequently, there is an undesirable variation in characteristics among the semiconductor devices. The invention provides a method for manufacturing PIN type diode which comprises an intermediate semiconductor region in which complex defects are formed. The method comprises introducing impurities (for example, carbon), which are the sane kind of impurities intrinsically contained in the intermediate semiconductor region, into the intermediate semiconductor region, and irradiating the intermediate semiconductor region with helium ions to form point defects.
    Type: Application
    Filed: May 19, 2006
    Publication date: December 14, 2006
    Inventors: Shinya Yamazaki, Tomoyoshi Kushida, Takahide Sugiyama
  • Patent number: 7038275
    Abstract: An object of this invention is to provide a buried gate-type semiconductor device in which its gate interval is minimized so as to improve channel concentration thereby realizing low ON-resistance, voltage-resistance depression due to convergence of electrical fields in the vicinity of the bottom of the gate is prevented and further prevention of voltage-resistance depression and OFF characteristic are achieved at the same time. A plurality of gate electrodes 106 each having a rectangular section are disposed in its plan section. The interval 106T between the long sides of the gate electrodes 106 is made shorter than the interval 106S between the short sides thereof. Further, a belt-like contact opening 108 is provided between the short sides of the gate electrode 106, so that P+ source region 100 and N+ source region 104 are in contact with a source electrode. Consequently, the interval 106T between the long sides of the gate electrode 106 can be set up regardless of the width of the contact opening 108.
    Type: Grant
    Filed: December 11, 2003
    Date of Patent: May 2, 2006
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventor: Tomoyoshi Kushida
  • Patent number: 6930353
    Abstract: It is intended to provide a field-effective-type semiconductor device that can let low ON-resistance and non-excessive short-circuit current go together by effectively using its channel width and prevents device from destruction. In a field-effective-type semiconductor device, a semiconductor region arranged between gate electrodes 106 has stripe-patterned structure consisting of an N+ emitter region 104 and a P emitter region. The P emitter region is constituted by P channel region 103 of low concentration and P+ emitter region 100 of high concentration. The N+ emitter region 104, the P channel region 103, and the P+ emitter region 100 are in contact with the emitter electrode 109. Thereby, a channel width X is limited to the extent that is enough for ON current under normal operation state. That is, low ON-resistance and not excessive short-circuit current can go together in the field-effective-type semiconductor device.
    Type: Grant
    Filed: October 29, 2003
    Date of Patent: August 16, 2005
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventors: Katsuhiko Nishiwaki, Tomoyoshi Kushida
  • Patent number: 6921941
    Abstract: It is intended to provide a high withstand voltage field effect type semiconductor device that relaxes electric fields in a semiconductor substrate without thickening thickness of a drift region and achieves withstand-ability against high voltage without sacrificing ON-voltage, switch-OFF characteristics, and miniaturization. A field effective type semiconductor device comprises emitter regions 100, 104 and gate electrodes 106 and the like on a surface (upper surface in FIG. 2), a collector region 101 and the like on the other surface (lower surface in FIG. 2), wherein N? field dispersion regions 111 of low impurity concentration are arranged between P body regions 103 facing to gate electrodes 106 and an N drift region 102 below P body regions 103. Thereby, electric field between collector and emitter is relaxed and high withstand voltage field effect type semiconductor device is realized.
    Type: Grant
    Filed: February 13, 2004
    Date of Patent: July 26, 2005
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventors: Katsuhiko Nishiwaki, Tomoyoshi Kushida, Sachiko Kawaji
  • Patent number: 6855983
    Abstract: A trench gate type semiconductor device has an ON resistance that has been reduced. The device has a drain electrode on one side of the substrate and has a drift region, channel region, source region, and a source electrode on the other side. The channel region is sandwiched between a trench gate region covered with insulating film. Current passes when a positive bias voltage is applied to the trench region, and current is cut off when a negative bias voltage is applied.
    Type: Grant
    Filed: November 8, 1999
    Date of Patent: February 15, 2005
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventor: Tomoyoshi Kushida
  • Publication number: 20040164349
    Abstract: It is intended to provide a high withstand voltage field effect type semiconductor device that relaxes electric fields in a semiconductor substrate without thickening thickness of a drift region and achieves withstand-ability against high voltage without sacrificing ON-voltage, switch-OFF characteristics, and miniaturization. A field effective type semiconductor device comprises emitter regions 100, 104 and gate electrodes 106 and the like on a surface (upper surface in FIG. 2), a collector region 101 and the like on the other surface (lower surface in FIG. 2), wherein N− field dispersion regions 111 of low impurity concentration are arranged between P body regions 103 facing to gate electrodes 106 and an N drift region 102 below P body regions 103. Thereby, electric field between collector and emitter is relaxed and high withstand voltage field effect type semiconductor device is realized.
    Type: Application
    Filed: February 13, 2004
    Publication date: August 26, 2004
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Katsuhiko Nishiwaki, Tomoyoshi Kushida, Sachiko Kawaji
  • Patent number: 6774407
    Abstract: The present invention provides a semiconductor device wherein the turning-off time thereof can be reduced substantially and, at the same time, the turned-on resistance thereof can also be prevented effectively from increasing as well. Lattice defects are distributed at a high concentration in a defect region an area in close proximity to the boundary surface between an n drift region and a p+ substrate. The half-value width of the distribution is set at a value which is large enough for the defect region to include a non-depletion region in the n drift region. However, the defect region is not spread to cover a diffusion layer. In this way, the turning-off time of the semiconductor device can be reduced considerably without being accompanied by an increase in turned-on resistance thereof. In addition, by employing an absorber with an uneven surface, the distribution of lattice defects can be obtained by carrying out radiation of ions at only one time.
    Type: Grant
    Filed: January 2, 2001
    Date of Patent: August 10, 2004
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventor: Tomoyoshi Kushida
  • Publication number: 20040119117
    Abstract: An object of this invention is to provide a buried gate-type semiconductor device in which its gate interval is minimized so as to improve channel concentration thereby realizing low ON-resistance, voltage-resistance depression due to convergence of electrical fields in the vicinity of the bottom of the gate is prevented and further prevention of voltage-resistance depression and OFF characteristic are achieved at the same time. A plurality of gate electrodes 106 each having a rectangular section are disposed in its plan section. The interval 106T between the long sides of the gate electrodes 106 is made shorter than the interval 106S between the short sides thereof. Further, a belt-like contact opening 108 is provided between the short sides of the gate electrode 106, so that P+ source region 100 and N+ source region 104 are in contact with a source electrode.
    Type: Application
    Filed: December 11, 2003
    Publication date: June 24, 2004
    Applicant: Toyoda Jidosha Kabushiki Kaisha
    Inventor: Tomoyoshi Kushida
  • Publication number: 20040084725
    Abstract: It is intended to provide a field-effective-type semiconductor device that can let low ON-resistance and non-excessive short-circuit current go together by effectively using its channel width and prevents device from destruction. In a field-effective-type semiconductor device, a semiconductor region arranged between gate electrodes 106 has stripe-patterned structure consisting of an N+ emitter region 104 and a P emitter region. The P emitter region is constituted by P channel region 103 of low concentration and P+ emitter region 100 of high concentration. The N+ emitter region 104, the P channel region 103, and the P+ emitter region 100 are in contact with the emitter electrode 109. Thereby, a channel width X is limited to the extent that is enough for ON current under normal operation state. That is, low ON-resistance and not excessive short-circuit current can go together in the field-effective-type semiconductor device.
    Type: Application
    Filed: October 29, 2003
    Publication date: May 6, 2004
    Applicant: Toyota Jidosha Kabushiki Kaisha
    Inventors: Katsuhiko Nishiwaki, Tomoyoshi Kushida
  • Patent number: 6518629
    Abstract: In a semiconductor device having high voltage resistance and low ON voltage characteristics, charge-storage regions (insulation layer) are formed in a drift region. Formed above the drift region are a channel region, an emitter region, trench-type gate electrodes, and an emitter electrode. Strips of the insulation layer extend in a direction intersecting a direction of extension of the gate electrodes, and form a stripe pattern. The insulation layer curbs extraction of holes into the channel region. Openings in the stripe pattern of the insulation layer form depletion layers.
    Type: Grant
    Filed: July 3, 2000
    Date of Patent: February 11, 2003
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventors: Tomoyoshi Kushida, Katsuhiko Nishiwaki
  • Publication number: 20010011745
    Abstract: The present invention provides a semiconductor device wherein the turning-off time thereof can be reduced substantially and, at the same time, the turned-on resistance thereof can also be prevented effectively from increasing as well. Lattice defects are distributed at a high concentration in a defect region an area in close proximity to the boundary surface between an n drift region and a p+ substrate. The half-value width of the distribution is set at a value which is large enough for the defect region to include a non-depletion region in the n drift region. However, the defect region is not spread to cover a diffusion layer. In this way, the turning-off time of the semiconductor device can be reduced considerably without being accompanied by an increase in turned-on resistance thereof. In addition, by employing an absorber with an uneven surface, the distribution of lattice defects can be obtained by carrying out radiation of ions at only one time.
    Type: Application
    Filed: January 2, 2001
    Publication date: August 9, 2001
    Applicant: Toyota Jidosha Kabushiki Kaisha
    Inventor: Tomoyoshi Kushida