Patents by Inventor Masaki Kurasawa
Masaki Kurasawa 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: 8652854Abstract: There are provided a capacitor lower electrode formed on an adhesive layer, whose surface roughness is 0.79 nm or less, and having a (111) orientation that is inclined from a perpendicular direction to an upper surface of a substrate by 2.3° or less, a ferroelectric layer having a structure the (111) orientation of which is inclined from the perpendicular direction to the upper surface of the substrate by 3.5° or less, and a capacitor upper electrode.Type: GrantFiled: March 12, 2012Date of Patent: February 18, 2014Assignee: Fujitsu Semiconductor LimitedInventors: Tomohiro Takamatsu, Junichi Watanabe, Ko Nakamura, Wensheng Wang, Naoyuki Sato, Aki Dote, Kenji Nomura, Yoshimasa Horii, Masaki Kurasawa, Kazuaki Takai
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Publication number: 20120276659Abstract: An impurity-doped PZT film in an amorphous state doped with La, Ca, Sr, Si, Nb and/or the like is formed on a Pt film composing a bottom electrode film. Next, crystallization annealing for the impurity-doped PZT film is performed. Next, a PZT film is formed on the impurity-doped PZT film by an MOCVD method. Thereafter, an IrOX film, an IrOY film and an Ir film are formed on the PZT film.Type: ApplicationFiled: July 10, 2012Publication date: November 1, 2012Applicant: Fujitsu Semiconductor LimitedInventors: Wensheng WANG, Masaki Kurasawa
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Publication number: 20120171785Abstract: There are provided a capacitor lower electrode formed on an adhesive layer, whose surface roughness is 0.79 nm or less, and having a (111) orientation that is inclined from a perpendicular direction to an upper surface of a substrate by 2.3° or less, a ferroelectric layer having a structure the (111) orientation of which is inclined from the perpendicular direction to the upper surface of the substrate by 3.5° or less, and a capacitor upper electrode.Type: ApplicationFiled: March 12, 2012Publication date: July 5, 2012Applicant: FUJITSU SEMICONDUCTOR LIMITEDInventors: Tomohiro Takamatsu, Junichi Watanabe, Ko Nakamura, Wensheng Wang, Naoyuki Sato, Aki Dote, Kenji Nomura, Yoshimasa Horii, Masaki Kurasawa, Kazuaki Takai
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Patent number: 8153448Abstract: There are provided a capacitor lower electrode formed on an adhesive layer, whose surface roughness is 0.79 nm or less, and having a (111) orientation that is inclined from a perpendicular direction to an upper surface of a substrate by 2.3° or less, a ferroelectric layer having a structure the (111) orientation of which is inclined from the perpendicular direction to the upper surface of the substrate by 3.5° or less, and a capacitor upper electrode.Type: GrantFiled: May 12, 2009Date of Patent: April 10, 2012Assignee: Fujitsu Semiconductor LimitedInventors: Tomohiro Takamatsu, Junichi Watanabe, Ko Nakamura, Wensheng Wang, Naoyuki Sato, Aki Dote, Kenji Nomura, Yoshimasa Horii, Masaki Kurasawa, Kazuaki Takai
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Patent number: 7883961Abstract: A manufacturing method for a ferroelectric memory device including: forming a lower electrode; forming an electrode oxide film composed of an oxide of a constituent material of the lower electrode; forming a first ferroelectric layer on the lower electrode by reaction between organometallic source material gas and oxygen gas; forming a second ferroelectric layer on the first ferroelectric layer by reaction between organometallic source material gas and oxygen gas; and forming an upper electrode on the second ferroelectric layer. In the method, the oxygen gas in the forming of the first ferroelectric layer is in an amount less than the amount of oxygen necessary for reaction of the organometallic source material gas. In the method, the oxygen gas in the forming of the second ferroelectric layer is in an amount greater than the amount of oxygen necessary for reaction of the organometallic source material gas.Type: GrantFiled: November 28, 2007Date of Patent: February 8, 2011Assignees: Seiko Epson Corporation, Fujitsu Semiconductor LimitedInventors: Hiroaki Tamura, Masaki Kurasawa, Hideki Yamawaki
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Patent number: 7674634Abstract: A semiconductor device incorporating a capacitor structure that includes a ferroelectric thin film is obtained by forming, on a single crystalline substrate 10 having a surface suited for growing thereon a thin film layer of ferroelectric single crystal having a plane (111), a ferroelectric single crystalline thin film 12? containing Pb and having a plane (111) 11 in parallel with the surface of the substrate (or a ferroelectric polycrystalline thin film containing Pb and oriented parallel with the plane (111) in parallel with the surface of the substrate) and part 16 of a circuit of a semiconductor device, to thereby fabricate the single crystalline substrate 10 having said ferroelectric thin film containing Pb and said part of the circuit of the semiconductor device; and bonding said single crystalline substrate 10 to another substrate on which the other circuit of the semiconductor device has been formed in advance, to couple the two circuits together.Type: GrantFiled: November 5, 2003Date of Patent: March 9, 2010Assignee: Fujitsu LimitedInventors: Kenji Maruyama, Masaki Kurasawa, Masao Kondo, Yoshihiro Arimoto
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Publication number: 20090280577Abstract: There are provided a capacitor lower electrode formed on an adhesive layer, whose surface roughness is 0.79 nm or less, and having a (111) orientation that is inclined from a perpendicular direction to an upper surface of a substrate by 2.3° or less, a ferroelectric layer having a structure the (111) orientation of which is inclined from the perpendicular direction to the upper surface of the substrate by 3.5° or less, and a capacitor upper electrode.Type: ApplicationFiled: May 12, 2009Publication date: November 12, 2009Applicant: FUJITSU MICROELECTRONICS LIMITEDInventors: Tomohiro TAKAMATSU, Junichi WATANABE, Ko NAKAMURA, Wensheng WANG, Naoyuki SATO, Aki DOTE, Kenji NOMURA, Yoshimasa HORII, Masaki KURASAWA, Kazuaki TAKAI
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Patent number: 7547933Abstract: There are provided a capacitor lower electrode formed on an adhesive layer, whose surface roughness is 0.79 nm or less, and having a (111) orientation that is inclined from a perpendicular direction to an upper surface of a substrate by 2.3° or less, a ferroelectric layer having a structure the (111) orientation of which is inclined from the perpendicular direction to the upper surface of the substrate by 3.5° or less, and a capacitor upper electrode.Type: GrantFiled: October 29, 2003Date of Patent: June 16, 2009Assignee: Fujitsu Microelectronics LimitedInventors: Tomohiro Takamatsu, Junichi Watanabe, Ko Nakamura, Wensheng Wang, Naoyuki Sato, Aki Dote, Kenji Nomura, Yoshimasa Horii, Masaki Kurasawa, Kazuaki Takai
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Patent number: 7423308Abstract: A ferroelectric capacitor includes a lower electrode, a ferroelectric film provided over the lower electrode and having a perovskite-type structure and an upper electrode provided over the ferroelectric film. The ferroelectric film includes a first ferroelectric film part having a first crystal system and formed along at least one interface with at least one of the lower electrode and the upper electrode and a second ferroelectric film part having a second crystal system that is different from the first crystal system.Type: GrantFiled: October 19, 2004Date of Patent: September 9, 2008Assignee: Fujitsu LimitedInventors: Masaki Kurasawa, Kenji Maruyama
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Publication number: 20080145953Abstract: A manufacturing method for a ferroelectric memory device including: forming a lower electrode; forming an electrode oxide film composed of an oxide of a constituent material of the lower electrode; forming a first ferroelectric layer on the lower electrode by reaction between organometallic source material gas and oxygen gas; forming a second ferroelectric layer on the first ferroelectric layer by reaction between organometallic source material gas and oxygen gas; and forming an upper electrode on the second ferroelectric layer. In the method, the oxygen gas in the forming of the first ferroelectric layer is in an amount less than the amount of oxygen necessary for reaction of the organometallic source material gas. In the method, the oxygen gas in the forming of the second ferroelectric layer is in an amount greater than the amount of oxygen necessary for reaction of the organometallic source material gas.Type: ApplicationFiled: November 28, 2007Publication date: June 19, 2008Inventors: Hiroaki Tamura, Masaki Kurasawa, Hideki Yamawaki
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Publication number: 20080061331Abstract: An impurity-doped PZT film in an amorphous state doped with La, Ca, Sr, Si, Nb and/or the like is formed on a Pt film composing a bottom electrode film. Next, crystallization annealing for the impurity-doped PZT film is performed. Next, a PZT film is formed on the impurity-doped PZT film by an MOCVD method. Thereafter, an IrOX film, an IrOY film and an Ir film are formed on the PZT film.Type: ApplicationFiled: January 25, 2007Publication date: March 13, 2008Applicant: FUJITSU LIMITEDInventors: Wensheng Wang, Masaki Kurasawa
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Patent number: 7176132Abstract: There are provided a step of forming an insulating film over a semiconductor substrate, a step of exciting a plasma of a gas having a molecular structure in which hydrogen and nitrogen are bonded and then irradiating the plasma onto the insulating film, a step of forming a self-orientation layer made of substance having a self-orientation characteristic on the insulating film, and a step of forming a first conductive film made of conductive substance having the self-orientation characteristic on the self-orientation layer.Type: GrantFiled: October 29, 2003Date of Patent: February 13, 2007Assignee: Fujitsu LimitedInventors: Naoya Sashida, Katsuyoshi Matsuura, Yoshimasa Horii, Masaki Kurasawa, Kazuaki Takai
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Patent number: 7153705Abstract: A method of manufacturing an electronic device includes the steps of: (a) preparing a (001) oriented ReO3 layer; and (b) forming a (001) oriented oxide ferroelectric layer having a perovskite structure on the ReO3 layer. Preferably, the step (a) includes the steps of: (a-1) preparing a (001) oriented MgO layer; and (a-2) forming a (001) oriented ReO3 layer on the MgO layer. An electronic device capable of obtaining a ferroelectric layer of a large polarization and a method of manufacturing the same are provided.Type: GrantFiled: April 12, 2004Date of Patent: December 26, 2006Assignee: Fujitsu LimitedInventors: Kenji Maruyama, Masao Kondo, Masaki Kurasawa
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Publication number: 20060166378Abstract: A semiconductor device incorporating a capacitor structure that includes a ferroelectric thin film is obtained by forming, on a single crystalline substrate 10 having a surface suited for growing thereon a thin film layer of ferroelectric single crystal having a plane (111), a ferroelectric single crystalline thin film 12? containing Pb and having a plane (111) 11 in parallel with the surface of the substrate (or a ferroelectric polycrystalline thin film containing Pb and oriented parallel with the plane (111) in parallel with the surface of the substrate) and part 16 of a circuit of a semiconductor device, to thereby fabricate the single crystalline substrate 10 having said ferroelectric thin film containing Pb and said part of the circuit of the semiconductor device; and bonding said single crystalline substrate 10 to another substrate on which the other circuit of the semiconductor device has been formed in advance, to couple the two circuits together.Type: ApplicationFiled: November 5, 2003Publication date: July 27, 2006Inventors: Kenji Maruyama, Masaki Kurasawa, Masao Kondo, Yoshihiro Arimoto
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Patent number: 7029984Abstract: A method is disclosed for fabricating a semiconductor device having a memory employing a ferroelectric capacitor in which the orientation of the ferroelectric film is controlled. The method for fabricating the semiconductor device includes a first film deposition process for forming a first ferroelectric layer, and a second film deposition process for forming a second ferroelectric layer on the first ferroelectric layer. The film deposition temperature of the first film deposition process is set to at least 600° C.Type: GrantFiled: May 25, 2005Date of Patent: April 18, 2006Assignee: Fujitsu LimitedInventors: Yoshimasa Horii, Masaaki Nakabayashi, Masaki Kurasawa, Kou Nakamura, Kazuaki Takai, Hideyuki Noshiro, Shigeyoshi Umemiya
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Patent number: 6974985Abstract: The semiconductor device comprises: a memory cell transistor formed on a semiconductor substrate 10; insulation films 22, 30 covering the memory cell transistor; a buffer structure 40 formed on the insulation film; and a capacitor including a lower electrode 42 formed on the buffer structure 40 and electrically connected to the source/drain diffused layer 20; a capacitor dielectric film 44 formed on the lower electrode 42, and formed of a perovskite ferroelectric material having a smaller thermal expansion coefficient than that of the buffer structure 40 and having a crystal oriented substantially perpendicular to a surface of the lower electrode 42. The buffer structure for mitigating the influence of the stress from the substrate is formed below the lower electrode, whereby a polarization direction of the capacitor dielectric film can be made parallel with a direction of an electric field applied between the upper electrode and the lower electrode.Type: GrantFiled: September 24, 2001Date of Patent: December 13, 2005Assignee: Fujitsu LimitedInventors: Masaki Kurasawa, Kazuaki Kurihara, Kenji Maruyama
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Publication number: 20050215006Abstract: A method is disclosed for fabricating a semiconductor device having a memory employing a ferroelectric capacitor in which the orientation of the ferroelectric film is controlled. The method for fabricating the semiconductor device includes a first film deposition process for forming a first ferroelectric layer, and a second film deposition process for forming a second ferroelectric layer on the first ferroelectric layer. The film deposition temperature of the first film deposition process is set to at least 600° C.Type: ApplicationFiled: May 25, 2005Publication date: September 29, 2005Applicant: FUJITSU LIMITEDInventors: Yoshimasa Horii, Masaaki Nakabayashi, Masaki Kurasawa, Kou Nakamura, Kazuaki Takai, Hideyuki Noshiro, Shigeyoshi Umemiya
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Patent number: 6943397Abstract: A device having a capacitor element includes: an underlying body having a non-orientated first surface; a lower electrode formed on the first surface of the underlying body, the lower electrode containing conductive metal oxide and not containing noble metal, such as LaNiO3, the conductive metal oxide having a (0 0 1) orientated ABO3 type pervskite structure; a ferroelectric layer formed on the lower electrode, having a rhombohedral ABO3 type pervskite structure, the ferroelectric layer being preferentially (0 0 1) orientated in conformity with the orientation of the lower electrode, and an upper electrode formed on the ferroelectric layer.Type: GrantFiled: August 26, 2003Date of Patent: September 13, 2005Assignee: Fujitsu LimitedInventors: Masao Kondo, Hideki Yamawaki, Kenji Maruyama, Kazuaki Kurihara, Masaharu Hida, Shigeyoshi Umemiya, Masaki Kurasawa
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Publication number: 20050167713Abstract: A ferroelectric capacitor including a bottom electrode layer, a ferroelectric layer on the bottom electrode layer, and a top electrode layer on the ferroelectric layer, in which a ferroelectric is formed on the bottom electrode layer so as to have a dominant axis of orientation, the bottom electrode layer has a multilayer structure, and the layers of the bottom electrode have larger coefficients of diffusion of component elements of the ferroelectric or compounds comprised of the component elements to the bottom electrode the closer the layers to the ferroelectric layer.Type: ApplicationFiled: February 23, 2005Publication date: August 4, 2005Applicant: FUJITSU LIMITEDInventor: Masaki Kurasawa
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Publication number: 20050052823Abstract: A ferroelectric capacitor includes a lower electrode, a ferroelectric film provided over the lower electrode and having a perovskite-type structure and an upper electrode provided over the ferroelectric film. The ferroelectric film includes a first ferroelectric film part having a first crystal system and formed along at least one interface with at least one of the lower electrode and the upper electrode and a second ferroelectric film part having a second crystal system that is different from the first crystal system.Type: ApplicationFiled: October 19, 2004Publication date: March 10, 2005Applicant: FUJITSU LIMITEDInventors: Masaki Kurasawa, Kenji Maruyama