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).
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Patent number: 9231081Abstract: 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: GrantFiled: February 28, 2013Date of Patent: January 5, 2016Assignee: SEIKO INSTRUMENTS INC.Inventor: Naoto Saitoh
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Patent number: 8710626Abstract: 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: GrantFiled: July 18, 2012Date of Patent: April 29, 2014Assignee: Seiko Instruments Inc.Inventors: Ayako Inoue, Naoto Saitoh
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Publication number: 20130244385Abstract: 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: ApplicationFiled: February 28, 2013Publication date: September 19, 2013Applicant: SEIKO INSTRUMENTS INC.Inventor: Naoto SAITOH
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Patent number: 8450797Abstract: 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: GrantFiled: September 6, 2011Date of Patent: May 28, 2013Assignee: Seiko Instruments Inc.Inventor: Naoto Saitoh
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Publication number: 20120280359Abstract: 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: ApplicationFiled: July 18, 2012Publication date: November 8, 2012Inventors: Ayako INOUE, Naoto SAITOH
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Patent number: 8247303Abstract: 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: GrantFiled: March 23, 2011Date of Patent: August 21, 2012Assignee: Seiko Instruments Inc.Inventors: Ayako Inoue, Naoto Saitoh
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Patent number: 8237222Abstract: 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: GrantFiled: February 16, 2010Date of Patent: August 7, 2012Assignee: Seiko Instruments Inc.Inventors: Ayako Inoue, Naoto Saitoh
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Publication number: 20120074490Abstract: 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: ApplicationFiled: September 6, 2011Publication date: March 29, 2012Inventor: Naoto Saitoh
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Publication number: 20110233724Abstract: 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: ApplicationFiled: March 23, 2011Publication date: September 29, 2011Inventors: Ayako Inoue, Naoto Saitoh
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Patent number: 7964457Abstract: 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: GrantFiled: August 4, 2009Date of Patent: June 21, 2011Assignee: Seiko Instruments Inc.Inventors: Naoto Saitoh, Yuichiro Kitajima
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Patent number: 7880235Abstract: 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: GrantFiled: December 12, 2006Date of Patent: February 1, 2011Assignee: Seiko Instruments Inc.Inventor: Naoto Saitoh
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Publication number: 20100219472Abstract: 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: ApplicationFiled: February 16, 2010Publication date: September 2, 2010Inventors: Ayako Inoue, Naoto Saitoh
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Patent number: 7575967Abstract: 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: GrantFiled: October 18, 2006Date of Patent: August 18, 2009Assignee: Seiko Instruments Inc.Inventors: Naoto Saitoh, Yuichiro Kitajima
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Publication number: 20070138558Abstract: 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: ApplicationFiled: December 12, 2006Publication date: June 21, 2007Inventor: Naoto Saitoh
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Publication number: 20070085137Abstract: 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: ApplicationFiled: October 18, 2006Publication date: April 19, 2007Inventors: Naoto Saitoh, Yuichiro Kitajima
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Patent number: 7161198Abstract: 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: GrantFiled: September 6, 2002Date of Patent: January 9, 2007Assignee: Seiko Instruments Inc.Inventors: Toshihiko Omi, Hitomi Watanabe, Kazutoshi Ishii, Naoto Saitoh
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Publication number: 20030049907Abstract: 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: ApplicationFiled: September 6, 2002Publication date: March 13, 2003Inventors: Toshihiko Omi, Hitomi Watanabe, Kazutoshi Ishii, Naoto Saitoh
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Patent number: 6156617Abstract: 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: GrantFiled: May 26, 1999Date of Patent: December 5, 2000Assignee: Seiko Instruments Inc.Inventor: Naoto Saitoh
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Patent number: 5905291Abstract: 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: GrantFiled: July 18, 1995Date of Patent: May 18, 1999Assignee: Seiko Instruments Inc.Inventors: Fumiyasu Utsunomiya, Yutaka Saitoh, Naoto Saitoh, Jun Osanai, Haruo Konishi, Masanori Miyagi