Patents by Inventor Kiyotaka Imai

Kiyotaka Imai 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: 7754570
    Abstract: Threshold voltage of a field effect transistor is successfully adjusted with a smaller dose of an impurity, as compared with a conventional adjustment of the threshold voltage only by doping an impurity into the channel region. A semiconductor device 100 has a silicon substrate 101 and a P-type MOSFET 103 comprising a SiON film 113 formed on the silicon substrate 101, and a polycrystalline silicon film 106. Any one of, or two or more of metals selected from the group consisting of Hf, Zr, Al, La, Pr, Y, Ti, Ta and W are allowed to reside at the interface 115 between the polycrystalline silicon film 106 and the SiON film 113, and concentration of the metal(s) at the interface 115 is adjusted to 5×1013 atoms/cm2 or more and less than 1.4×1015 atoms/cm2.
    Type: Grant
    Filed: August 25, 2005
    Date of Patent: July 13, 2010
    Assignees: NEC Electronics Corporation, NEC Corporation
    Inventors: Naohiko Kimizuka, Kiyotaka Imai, Yuri Masuoka, Toshiyuki Iwamoto
  • Publication number: 20100117156
    Abstract: A semiconductor device includes a first transistor, a second transistor, a first interconnect, a second interconnect, and a first gate electrode. The first gate electrode is a gate electrode of the first and second transistors and extends linearly over first and second channel regions. In addition, a first source of the first transistor is located at the opposite side of a second source of the second transistor with the first gate electrode interposed therebetween, and a first drain of the first transistor is located at the opposite side of a second drain of the second transistor with the first gate electrode interposed therebetween.
    Type: Application
    Filed: November 12, 2009
    Publication date: May 13, 2010
    Applicant: NEC ELECTRONICS CORPORATION
    Inventors: Gen TSUTSUI, Kiyotaka IMAI
  • Publication number: 20080093699
    Abstract: The semiconductor device includes a plurality of transistors at least having different channel widths from each other. Threshold voltages of those transistors are set to be substantially equal to each other, by using both of substantially the same channel dose for each of those transistors, and work function control using a predetermined metal to be deposited on a gate insulating of those transistors and/or a gate electrode material of each of those transistors (that is, work function control based on a gate structure (gate insulating film and/or gate electrode) with respect to a channel region of each of those transistors).
    Type: Application
    Filed: October 18, 2007
    Publication date: April 24, 2008
    Applicant: NEC ELECTRONICS CORPORATION
    Inventors: Tomohisa ABE, Gen Tsutsui, Tadashi Fukase, Yasushi Nakahara, Kiyotaka Imai
  • Patent number: 7238996
    Abstract: A semiconductor device 100 comprises a silicon substrate 102, an N-type MOSFET 118 including a high concentration-high dielectric constant film 108b formed on the silicon substrate 102 and a polycrystalline silicon film 114, and a P-type MOSFET 120 including a low concentration-high dielectric constant film 108a and a polycrystalline silicon film 114 formed on the semiconductor substrate 102 to be juxtaposed to the N-type MOSFET 118. The low concentration-high dielectric constant film 108a and the high concentration-high dielectric constant film 108b are composed of a material containing one or more element (s) selected from a group consisting of Hf and Zr. The concentration of the above-described metallic element contained in the low concentration-high dielectric constant film 108a is lower than that contained in the high concentration-high dielectric constant film 108b.
    Type: Grant
    Filed: May 16, 2005
    Date of Patent: July 3, 2007
    Assignees: NEC Electronics Corporation, NEC Corporation
    Inventors: Naohiko Kimizuka, Kiyotaka Imai, Yuri Masuoka, Toshiyuki Iwamoto, Motofumi Saitoh, Hirohito Watanabe, Ayuka Tada
  • Patent number: 7157322
    Abstract: A semiconductor device including an NMOSFET which has an n-type source/drain main region containing arsenic and an n-type source/drain buffer region having arsenic and phosphorous of which a concentration is lower than that of the source/drain main region, and the concentration of the phosphorous in the source/drain buffer region is smaller than the concentration of the arsenic therein. The semiconductor device has a suppressed reverse short channel effect and reduced p-n junction leakage current. Further, the semiconductor device has a larger margin to a certain gate length and a specified threshold voltage to elevate a production yield.
    Type: Grant
    Filed: April 10, 2001
    Date of Patent: January 2, 2007
    Assignee: NEC Electronics Corporation
    Inventor: Kiyotaka Imai
  • Publication number: 20060252264
    Abstract: A semiconductor device includes: a semiconductor substrate; a semiconductor element formed on the semiconductor substrate and containing a gate electrode; impurity diffusion layers formed at both sides, in a cross-section in a gate length direction of the gate electrode, of a region on which the semiconductor element is formed of the semiconductor substrate; first silicide films formed respectively at the surface of the impurity diffusion layers, composed of a silicide compound of a first metal; and a second silicide film, formed at least at the surface of the gate electrode, composed of a silicide compound of a second metal different to the first metal. The silicide compound of the second metal has a silicidation temperature lower than the silicidation temperature of the silicide compound of the first metal.
    Type: Application
    Filed: May 3, 2006
    Publication date: November 9, 2006
    Applicant: NEC ELECTRONICS CORPORATION
    Inventors: Naohiko Kimizuka, Kiyotaka Imai
  • Patent number: 7102183
    Abstract: In P-channel MOS transistor comprising a gate insulating film composed of a high dielectric constant material and the gate electrode composed of polycrystalline silicon, a technology for preventing Fermi level pinning and providing a stable reduction of the threshold voltage is provided. The MOS transistor functions as a buried channel transistor formed by implanting In as a P-type impurity into the channel region. In addition, the gate electrode is composed of the polycrystalline silicon film, which is doped with N-type impurity. Thus, the gate depletion caused by Fermi level pinning can be effectively inhibited. Therefore the depletion in the gate electrode can be avoided and the threshold voltage can be stably diminished. In this case, the threshold voltage is stably reduced since electric charge is induced by applying a constant voltage to the gate electrode.
    Type: Grant
    Filed: December 2, 2004
    Date of Patent: September 5, 2006
    Assignee: NEC Electronics Corporation
    Inventors: Naohiko Kimizuka, Kiyotaka Imai, Yuri Masuoka
  • Publication number: 20060145265
    Abstract: While forming an N-type MOSFET 118 and a P-type MOSFET 120 within regions operating using the same power supply voltage, thickness of a gate insulating film 106a of an N-type MOSFET 118 is made to be thicker than thickness of a gate insulating film 106b of a P-type MOSFET 120.
    Type: Application
    Filed: December 15, 2005
    Publication date: July 6, 2006
    Inventors: Yuri Masuoka, Naohiko Kimizuka, Kiyotaka Imai, Toshiyuki Iwamoto
  • Publication number: 20060043497
    Abstract: Threshold voltage of a field effect transistor is successfully adjusted with a smaller dose of an impurity, as compared with a conventional adjustment of the threshold voltage only by doping an impurity into the channel region. A semiconductor device 100 has a silicon substrate 101 and a P-type MOSFET 103 comprising a SiON film 113 formed on the silicon substrate 101, and a polycrystalline silicon film 106. Any one of, or two or more of metals selected from the group consisting of Hf, Zr, Al, La, Pr, Y, Ti, Ta and W are allowed to reside at the interface 115 between the polycrystalline silicon film 106 and the SiON film 113, and concentration of the metal(s) at the interface 115 is adjusted to 5×1013 atoms/cm2 or more and less than 1.4×1015 atoms/cm2.
    Type: Application
    Filed: August 25, 2005
    Publication date: March 2, 2006
    Applicants: NEC ELECTRONICS CORPORATION, NEC CORPORATION
    Inventors: Naohiko Kimizuka, Kiyotaka Imai, Yuri Masuoka, Toshiyuki Iwamoto
  • Publication number: 20050263802
    Abstract: A semiconductor device 100 comprises a silicon substrate 102, an N-type MOSFET 118 including a high concentration-high dielectric constant film 108b formed on the silicon substrate 102 and a polycrystalline silicon film 114, and a P-type MOSFET 120 including a low concentration-high dielectric constant film 108a and a polycrystalline silicon film 114 formed on the semiconductor substrate 102 to be juxtaposed to the N-type MOSFET 118. The low concentration-high dielectric constant film 108a and the high concentration-high dielectric constant film 108b are composed of a material containing one or more element (s) selected from a group consisting of Hf and Zr. The concentration of the above-described metallic element contained in the low concentration-high dielectric constant film 108a is lower than that contained in the high concentration-high dielectric constant film 108b.
    Type: Application
    Filed: May 16, 2005
    Publication date: December 1, 2005
    Applicants: NEC ELECTRONICS CORPORATION, NEC CORPORATION
    Inventors: Naohiko Kimizuka, Kiyotaka Imai, Yuri Masuoka, Toshiyuki Iwamoto, Motofumi Saitoh, Hirohito Watanabe, Ayuka Tada
  • Publication number: 20050253181
    Abstract: The semiconductor device 100 comprises a silicon substrate 102, an N-type MOSFET 118 including a first high dielectric constant film 111 and a polycrystalline silicon film 114 formed on the silicon substrate 102, and a P-type MOSFET 120 including a second high dielectric constant film 112 and a polycrystalline silicon film 114 juxtaposed to N-type MOSFET 118 on the silicon substrate 102. The second high dielectric constant film 112 is formed to have the film thickness thinner than the film thickness of the first high dielectric constant film 111. The first high dielectric constant film 111 and the second high dielectric constant film 112 contains one or more element(s) selected from a group consisting of Hf and Zr.
    Type: Application
    Filed: May 16, 2005
    Publication date: November 17, 2005
    Applicants: NEC ELECTRONICS CORPORATION, NEC CORPORATION
    Inventors: Naohiko Kimizuka, Kiyotaka Imai, Yuri Masuoka, Toshiyuki Iwamoto, Motofumi Saitoh, Hirohito Watanabe, Masayuki Terai
  • Publication number: 20050224857
    Abstract: In P-channel MOS transistor comprising a gate insulating film composed of a high dielectric constant material and the gate electrode composed of polycrystalline silicon, a technology for preventing Fermi level pinning and providing a stable reduction of the threshold voltage is provided. The MOS transistor functions as a buried channel transistor formed by implanting In as a P-type impurity into the channel region. In addition, the gate electrode is composed of the polycrystalline silicon film, which is doped with N-type impurity. Thus, the gate depletion caused by Fermi level pinning can be effectively inhibited. Therefore the depletion in the gate electrode can be avoided and the threshold voltage can be stably diminished. In this case, the threshold voltage is stably reduced since electric charge is induced by applying a constant voltage to the gate electrode.
    Type: Application
    Filed: December 2, 2004
    Publication date: October 13, 2005
    Applicant: NEC ELECTRONICS CORPORATION
    Inventors: Naohiko Kimizuka, Kiyotaka Imai, Yuri Masuoka
  • Patent number: 6756676
    Abstract: In a semiconductor device having a multilayer metallization structure using SiOF film as an interlayer insulating film, with respect to the interlayer insulating film, the fluorine concentration of SiOF films (11, 16) in a wiring gap portion in the same layer wiring is set to be higher than the fluorine concentration of SiOF films (12, 17) between the upper and lower layer wirings (8, 15; 15, 20).
    Type: Grant
    Filed: May 23, 2001
    Date of Patent: June 29, 2004
    Assignee: NEC Electronics Corporation
    Inventors: Noriaki Oda, Kiyotaka Imai
  • Patent number: 6664148
    Abstract: In an integrated circuit device, third transistors having the thickest gate insulation film are driven at high voltage and thus operate at high speed with minimal gate leak current. First transistors having the thinnest gate insulation film and second transistors which do not have the thinnest gate insulation film are driven at low voltage, the second transistors being driven at all times and the first transistors being halted as appropriate. The second transistors operate constantly at low speed and with minimal gate leak current, and the first transistors, which have significant gate leak current, operate at high speed while halting as appropriate.
    Type: Grant
    Filed: February 12, 2002
    Date of Patent: December 16, 2003
    Assignee: NEC Corporation
    Inventors: Yoshiro Goto, Kiyotaka Imai, Naohiko Kimizuka
  • Publication number: 20030227059
    Abstract: A BOX layer and an SOI layer are formed on a P type silicon substrate and a P well and an N well are formed in the SOI layer. First P type diffusion regions positioned below S/D regions, a second P type diffusion region positioned below a channel region, a third P type diffusion region positioned between an STI region 4 and a BOX layer 2, and a fourth P type diffusion region as a body contact are formed within the P well, and the second and third P type diffusion regions are positioned at the same level, and further, the second and third P type diffusion regions are formed to have a dopant concentration higher than that of the first P type diffusion region.
    Type: Application
    Filed: June 10, 2003
    Publication date: December 11, 2003
    Applicant: NEC ELECTRONICS CORPORATION
    Inventors: Shinichi Miyake, Kiyotaka Imai, Masahiro Ikeda, Tomohiko Kudo
  • Publication number: 20030183880
    Abstract: According to a present invention, a gate electrode and a lower electrode are formed on a semiconductor substrate and a silicide layer is formed on the gate electrode and the lower electrode. Then, a capacitor insulating film functioning as an etching stopper is formed on the entire surface and a silicide layer is formed on the entire surface. After selectively forming the silicide layer to form the upper electrode and a silicide resistance element, a layer insulating film is on the entire surface and then contact holes are formed in the layer insulating film until the capacitor insulating film is exposed. Then, the capacitor insulating film is removed to expose the gate electrode, the lower electrode, the upper electrode and the resistance element.
    Type: Application
    Filed: March 25, 2003
    Publication date: October 2, 2003
    Inventors: Yoshiro Goto, Kiyotaka Imai
  • Patent number: 6627490
    Abstract: A core section complementary transistor and a memory cell section complementary transistor are formed on a semiconductor substrate of a first conductivity type. The core section complementary transistor has a first well of a second conductivity type provided in the semiconductor substrate, a first core section MOS transistor provided on the first well of the second conductivity type, a second core section MOS transistor provided on the semiconductor substrate a device separation film which separates the first core section MOS transistor and the second core section MOS transistor from each other, and a well of the first conductivity type provided under a part of the device separation film which is closer to the second core section MOS transistor. The first core section MOS transistor has source-drain regions of the first conductivity type. The second core section MOS transistor has source-drain regions of the second conductivity type.
    Type: Grant
    Filed: August 16, 2002
    Date of Patent: September 30, 2003
    Assignee: NEC Electronics Corporation
    Inventors: Sadaaki Masuoka, Kiyotaka Imai
  • Patent number: 6573027
    Abstract: The present invention relates to a method of manufacturing a semiconductor device; which comprises the steps of forming a film of a hard mask material, on a pattern-forming film which is to be used to form a prescribed pattern, and then forming a photoresist film over said film of the hard mask material; carrying out a first exposure using a first mask with a phase shifter and subsequently making a development; etching said film of the hard mask material using the formed resist pattern as a mask; forming a photoresist film so as to cover the formed hard mask pattern; carrying out a second exposure using a second mask with a pattern which enables a portion of the photoresist covering only a required part of said hard mask pattern to remain after the exposure and the development, and subsequently making a development; removing, by means of etching, an unrequited part of the hard mask which is not covered with any portion of said photoresist; and etching said pattern-forming film using the remaining hard mask pa
    Type: Grant
    Filed: February 3, 2000
    Date of Patent: June 3, 2003
    Assignee: NEC Corporation
    Inventor: Kiyotaka Imai
  • Publication number: 20030032250
    Abstract: In accordance with the present invention, the gate length and the gate insulation film thickness are different between the p-channel MOS field effect transistors serving as the driver gates and the n-channel MOS field effect transistors forming the flip flop. Namely, the p-channel MOS field effect transistors serving as the driver gates have a larger gate length and a smaller gate oxide film thickness than the n-channel MOS field effect transistors forming the flip flop.
    Type: Application
    Filed: October 18, 1999
    Publication date: February 13, 2003
    Inventor: KIYOTAKA IMAI
  • Publication number: 20030001175
    Abstract: A core section complementary transistor and a memory cell section complementary transistor are formed on a semiconductor substrate of a first conductivity type. The core section complementary transistor has a first well of a second conductivity type provided in the semiconductor substrate, a first core section MOS transistor provided on the first well of the second conductivity type, a second core section MOS transistor provided on the semiconductor substrate a device separation film which separates the first core section MOS transistor and the second core section MOS transistor from each other, and a well of the first conductivity type provided under a part of the device separation film which is closer to the second core section MOS transistor. The first core section MOS transistor has source-drain regions of the first conductivity type. The second core section MOS transistor has source-drain regions of the second conductivity type.
    Type: Application
    Filed: August 16, 2002
    Publication date: January 2, 2003
    Inventors: Sadaaki Masuoka, Kiyotaka Imai