Patents by Inventor Naoto Saitoh

Naoto Saitoh 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: 9231081
    Abstract: In a method of manufacturing a semiconductor device, a body region is formed in an epitaxial layer provided on a semiconductor substrate. A part of a semiconductor material forming the body region surface is removed to form a convex-type contact region protruding from the body region surface and to form a shallow trench surrounding the convex-type contact region. A deep trench region is formed so as to extend from the shallow trench surface to inside of the epitaxial layer. A gate insulating film is formed on an inner wall of the deep trench region which is filled with polycrystalline silicon that is held in contact with the gate insulating film. A source region and a body contact region are formed in the shallow trench and the convex-type contact region, respectively, and a silicide layer is formed to connect the source region and the body contact region to each other.
    Type: Grant
    Filed: February 28, 2013
    Date of Patent: January 5, 2016
    Assignee: SEIKO INSTRUMENTS INC.
    Inventor: Naoto Saitoh
  • Patent number: 8710626
    Abstract: Provided is a semiconductor capacitor including: a capacitor device forming region having a trapezoidal trench which is formed on a surface of a first conductivity type semiconductor substrate; a second conductivity type lower electrode layer provided along the trapezoidal trenches of the capacitor device forming region; a capacitor insulating film formed at least on a surface of the second conductivity type lower electrode layer; and a second conductivity type upper electrode formed on a surface of the capacitor insulating film.
    Type: Grant
    Filed: July 18, 2012
    Date of Patent: April 29, 2014
    Assignee: Seiko Instruments Inc.
    Inventors: Ayako Inoue, Naoto Saitoh
  • Publication number: 20130244385
    Abstract: Provided is a method of manufacturing a trench MOSFET through use of a simple process having good controllability, which is capable of forming the trench MOSFET on the same substrate as a CMOS transistor and capable of reducing the element area. The method of manufacturing a trench MOSFET includes a formation of a three-dimensional body contact region. Thus, the trench MOSFET can have a structure which can ensure a contact similar to that in a conventional case even in a smaller area.
    Type: Application
    Filed: February 28, 2013
    Publication date: September 19, 2013
    Applicant: SEIKO INSTRUMENTS INC.
    Inventor: Naoto SAITOH
  • Patent number: 8450797
    Abstract: To realize forming a trench MOSFET in which a depth of a P-body is changed on the same surface as a CMOS by employing steps with good controllability and without greatly increasing the number of manufacturing steps, provided is a trench MOSFET including an extended body region (10), which is a part of a P-body region (4) and is provided in a vicinity of a deep trench (5) with a distance, the extended body region (10) being diffused deeper than the P-body region (4).
    Type: Grant
    Filed: September 6, 2011
    Date of Patent: May 28, 2013
    Assignee: Seiko Instruments Inc.
    Inventor: Naoto Saitoh
  • Publication number: 20120280359
    Abstract: Provided is a semiconductor capacitor including: a capacitor device forming region having a trapezoidal trench which is formed on a surface of a first conductivity type semiconductor substrate; a second conductivity type lower electrode layer provided along the trapezoidal trenches of the capacitor device forming region; a capacitor insulating film formed at least on a surface of the second conductivity type lower electrode layer; and a second conductivity type upper electrode formed on a surface of the capacitor insulating film.
    Type: Application
    Filed: July 18, 2012
    Publication date: November 8, 2012
    Inventors: Ayako INOUE, Naoto SAITOH
  • Patent number: 8247303
    Abstract: Provided is a semiconductor capacitor including: a capacitor device forming region having a trapezoidal trench which is formed on a surface of a first conductivity type semiconductor substrate; a second conductivity type lower electrode layer provided along the trapezoidal trenches of the capacitor device forming region; a capacitor insulating film formed at least on a surface of the second conductivity type lower electrode layer; and a second conductivity type upper electrode formed on a surface of the capacitor insulating film.
    Type: Grant
    Filed: March 23, 2011
    Date of Patent: August 21, 2012
    Assignee: Seiko Instruments Inc.
    Inventors: Ayako Inoue, Naoto Saitoh
  • Patent number: 8237222
    Abstract: In a method of manufacturing a high withstanding voltage MOSFET, a region to be doped with impurities and a region to be doped with no impurity are provided when ion implantation of the impurities is performed in the channel forming region, for controlling a threshold voltage. The region to be doped with no impurity is suitably patterned so that impurity concentration of the channel forming region near boundaries between a well region and a source region and between the well region and a drain region having the same conductivity type as the well region may be increased, to thereby induce a reverse short channel effect. By canceling a short channel effect with the reverse short channel effect induced by the above-mentioned method, the short channel effect of the high withstanding voltage MOSFET may be suppressed.
    Type: Grant
    Filed: February 16, 2010
    Date of Patent: August 7, 2012
    Assignee: Seiko Instruments Inc.
    Inventors: Ayako Inoue, Naoto Saitoh
  • Publication number: 20120074490
    Abstract: To realize forming a trench MOSFET in which a depth of a P-body is changed on the same surface as a CMOS by employing steps with good controllability and without greatly increasing the number of manufacturing steps, provided is a trench MOSFET including an extended body region (10), which is a part of a P-body region (4) and is provided in a vicinity of a deep trench (5) with a distance, the extended body region (10) being diffused deeper than the P-body region (4).
    Type: Application
    Filed: September 6, 2011
    Publication date: March 29, 2012
    Inventor: Naoto Saitoh
  • Publication number: 20110233724
    Abstract: Provided is a semiconductor capacitor including: a capacitor device forming region having a trapezoidal trench which is formed on a surface of a first conductivity type semiconductor substrate; a second conductivity type lower electrode layer provided along the trapezoidal trenches of the capacitor device forming region; a capacitor insulating film formed at least on a surface of the second conductivity type lower electrode layer; and a second conductivity type upper electrode formed on a surface of the capacitor insulating film.
    Type: Application
    Filed: March 23, 2011
    Publication date: September 29, 2011
    Inventors: Ayako Inoue, Naoto Saitoh
  • Patent number: 7964457
    Abstract: Provided is a manufacturing method for a power management semiconductor device or an analog semiconductor device both including a CMOS. According to the method, a substance having high thermal conductivity is additionally provided above a semiconductor region constituting a low impurity concentration drain region so as to expand the drain region, which contributes to a promotion of thermal conductivity (or thermal emission) in the drain region during a surge input and leads to suppression of local temperature increase, to thereby prevent thermal destruction. Therefore, it is possible to manufacture a power management semiconductor device or an analog semiconductor device with the extended possibility of transistor design.
    Type: Grant
    Filed: August 4, 2009
    Date of Patent: June 21, 2011
    Assignee: Seiko Instruments Inc.
    Inventors: Naoto Saitoh, Yuichiro Kitajima
  • Patent number: 7880235
    Abstract: A semiconductor integrated circuit device has an SOI substrate comprising an insulating film laminated on a semiconductor support substrate and a semiconductor thin film laminated on the insulating film. A first N-channel MOS transistor, a first P-channel MOS transistor, and a resistor are each disposed on the semiconductor thin film. A second N-channel MOS transistor serving as an electrostatic discharge (ESD) protection element is disposed on a surface of the semiconductor support substrate that is exposed by removing a part of the semiconductor thin film and a part of the insulating film. The second N-channel MOS transistor has a gate electrode, a source region and a drain region surrounding the source region through the gate electrode to maintain a constant distance between the drain region and the source region.
    Type: Grant
    Filed: December 12, 2006
    Date of Patent: February 1, 2011
    Assignee: Seiko Instruments Inc.
    Inventor: Naoto Saitoh
  • Publication number: 20100219472
    Abstract: In a method of manufacturing a high withstanding voltage MOSFET, a region to be doped with impurities and a region to be doped with no impurity are provided when ion implantation of the impurities is performed in the channel forming region, for controlling a threshold voltage. The region to be doped with no impurity is suitably patterned so that impurity concentration of the channel forming region near boundaries between a well region and a source region and between the well region and a drain region having the same conductivity type as the well region may be increased, to thereby induce a reverse short channel effect. By canceling a short channel effect with the reverse short channel effect induced by the above-mentioned method, the short channel effect of the high withstanding voltage MOSFET may be suppressed.
    Type: Application
    Filed: February 16, 2010
    Publication date: September 2, 2010
    Inventors: Ayako Inoue, Naoto Saitoh
  • Patent number: 7575967
    Abstract: In a manufacturing method for a semiconductor device, a first impurity diffusion layer for a low impurity concentration drain of a second conductivity type is formed within a semiconductor layer of a first conductivity type, and a second impurity diffusion layer for a high impurity concentration drain of the second conductivity type is formed adjacent to the first impurity diffusion layer, with the second impurity diffusion layer having a higher impurity concentration than the first impurity diffusion layer. An interlayer insulating film is formed on the semiconductor substrate layer. A drain extension region having a high thermal conductivity is formed on a surface of the first impurity diffusion layer. A contact hole is formed through the interlayer insulating film and up to the second impurity diffusion layer.
    Type: Grant
    Filed: October 18, 2006
    Date of Patent: August 18, 2009
    Assignee: Seiko Instruments Inc.
    Inventors: Naoto Saitoh, Yuichiro Kitajima
  • Publication number: 20070138558
    Abstract: In a protection NMOS transistor serving as an ESD input/output protection element formed on a semiconductor support substrate, a drain region of the N-type protection transistor is formed so as to surround the source region, and a minimum distance between the source and the drain is kept constant, which makes it possible to ensure a sufficient ESD breakdown strength and to realize a structure capable of protecting input/output terminal, particularly an output terminal, of the fully depleted SOI CMOS device vulnerable to ESD noise.
    Type: Application
    Filed: December 12, 2006
    Publication date: June 21, 2007
    Inventor: Naoto Saitoh
  • Publication number: 20070085137
    Abstract: Provided is a manufacturing method for a power management semiconductor device or an analog semiconductor device both including a CMOS. According to the method, a substance having high thermal conductivity is additionally provided above a semiconductor region constituting a low impurity concentration drain region so as to expand the drain region, which contributes to a promotion of thermal conductivity (or thermal emission) in the drain region during a surge input and leads to suppression of local temperature increase, to thereby prevent thermal destruction. Therefore, it is possible to manufacture a power management semiconductor device or an analog semiconductor device with the extended possibility of transistor design.
    Type: Application
    Filed: October 18, 2006
    Publication date: April 19, 2007
    Inventors: Naoto Saitoh, Yuichiro Kitajima
  • Patent number: 7161198
    Abstract: An N-channel MOS transistor of a semiconductor device having a high withstand voltage employs a drain structure with a low concentration and a large diffusion depth, which causes a problem in that a sufficiently high withstand voltage cannot be obtained due to a parasitic NPN transistor formed among the drain, the well, and the semiconductor substrate which are arranged in the stated order.
    Type: Grant
    Filed: September 6, 2002
    Date of Patent: January 9, 2007
    Assignee: Seiko Instruments Inc.
    Inventors: Toshihiko Omi, Hitomi Watanabe, Kazutoshi Ishii, Naoto Saitoh
  • Publication number: 20030049907
    Abstract: An N-channel MOS transistor of a semiconductor device having a high withstand voltage employs a drain structure with a low concentration and a large diffusion depth, which causes a problem in that a sufficiently high withstand voltage cannot be obtained due to a parasitic NPN transistor formed among the drain, the well, and the semiconductor substrate which are arranged in the stated order.
    Type: Application
    Filed: September 6, 2002
    Publication date: March 13, 2003
    Inventors: Toshihiko Omi, Hitomi Watanabe, Kazutoshi Ishii, Naoto Saitoh
  • Patent number: 6156617
    Abstract: When a bipolar transistor having a buried layer is formed, the withstanding pressure of the bipolar transistor is deteriorated by upward diffusion to a great extent from the buried layer. When a buried layer is formed in a semiconductor substrate, by providing a region without impurity introduction, upward diffusion from the buried layer is controlled to prevent deterioration in the withstanding pressure.
    Type: Grant
    Filed: May 26, 1999
    Date of Patent: December 5, 2000
    Assignee: Seiko Instruments Inc.
    Inventor: Naoto Saitoh
  • Patent number: 5905291
    Abstract: A semiconductor integrated circuit device comprises at least two MISFETs formed on a semiconductor substrate and connected in series in a diode connection. Each of the MISFETs has a source, a drain, a channel extending between the source and the drain, and a gate disposed over the channel through a gate insulating film. One of the MISFETs has a first threshold voltage, and the other of the MISFETs has a second threshold voltage lower than the first threshold voltage. A portion of the channel of the semiconductor substrate of each of the MISFETs has an impurity concentration equal to or less than 6.times.10.sup.14 atoms/cc.
    Type: Grant
    Filed: July 18, 1995
    Date of Patent: May 18, 1999
    Assignee: Seiko Instruments Inc.
    Inventors: Fumiyasu Utsunomiya, Yutaka Saitoh, Naoto Saitoh, Jun Osanai, Haruo Konishi, Masanori Miyagi