Patents by Inventor Takahiro Yajima
Takahiro Yajima 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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Publication number: 20030124819Abstract: The photovoltaic element of the present invention is a photovoltaic element comprised of a semiconductor-junctioned element, characterized in that the element includes a first electrically conductive type semiconductor layer, a non-crystalline i type semiconductor layer, a microcrystalline i type semiconductor layer and a microcrystalline second electrically conductive type semiconductor layer and is pin-junctioned, and a method of and an apparatus for manufacturing the same are characterized by efficiently and continuously mass-producing the photovoltaic element having an excellent current-voltage characteristic and excellent photoelectric conversion efficiency.Type: ApplicationFiled: March 1, 2002Publication date: July 3, 2003Inventors: Shotaro Okabe, Yasushi Fujioka, Masahiro Kanai, Akira Sakai, Tadashi Sawayama, Yuzo Kohda, Tadashi Hori, Takahiro Yajima
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Patent number: 6531654Abstract: In a semiconductor thin-film formation process comprising feeding a semiconductor thin-film material gas into a discharge space, and applying a high-frequency power thereto to cause plasma to take place and decompose the material gas to form an amorphous semiconductor thin film on a desired substrate, the high-frequency power is applied changing its power density continuously or stepwise from a high power density to a low power density and thereafter again changing the power density continuously or stepwise from a low power density to a high power density, to form a semiconductor thin film made different in film quality in the direction of layer thickness while retaining the same conductivity type. This process enable formation of high-quality semiconductor thin films by plasma CVD.Type: GrantFiled: May 22, 2001Date of Patent: March 11, 2003Assignee: Canon Kabushiki KaishaInventors: Shuichiro Sugiyama, Masahiro Kanai, Takahiro Yajima
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Patent number: 6530341Abstract: A deposition apparatus of the present invention is arranged so that a surface area of a radio-frequency power applying cathode electrode disposed in a glow discharge space, in a space in contact with discharge is greater than a surface area of the whole of a ground electrode (anode electrode) including a beltlike member in the discharge space. This structure can maintain the potential (self-bias) of the cathode electrode disposed in the glow discharge space automatically at a positive potential with respect to the ground (anode) electrode including the beltlike member. As a result, the bias is applied in the direction of irradiation of ions with positive charge to a deposit film on the beltlike member, so that the ions existing in the plasma discharge are accelerated more efficiently toward the beltlike member, thereby effectively giving energy to the surface of deposit film by ion bombardment.Type: GrantFiled: February 25, 1999Date of Patent: March 11, 2003Assignee: Canon Kabushiki KaishaInventors: Yuzo Kohda, Shotaro Okabe, Masahiro Kanai, Akira Sakai, Tadashi Hori, Tomonori Nishimoto, Takahiro Yajima
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Patent number: 6526910Abstract: A film-forming apparatus by means of plasma CVD, comprising at least a vacuum chamber, a power application electrode for introducing a discharging power into said vacuum chamber, and a raw material gas supply means for supplying a film-forming raw material gas into said vacuum chamber, said power application electrode being arranged in said vacuum chamber so as to oppose to a substrate arranged in said vacuum chamber, characterized in that said power application electrode has a reinforcing member or said power application electrode comprises a power application electrode with no reinforcing member which has a thickness which is greater than a distance between said substrate and said power application electrode. A film-forming method using said film-forming apparatus.Type: GrantFiled: December 4, 2000Date of Patent: March 4, 2003Assignee: Canon Kabushiki KaishaInventors: Takahiro Yajima, Masahiro Kanai, Takeshi Shishido
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Publication number: 20030022519Abstract: The invention provides a process for producing a semiconductor layer by introducing a raw gas into a discharge chamber and supplying high-frequency power to the chamber to decompose the raw gas by discharge, thereby forming a semiconductor layer on a substrate within the discharge chamber, the process comprising the steps of supplying high-frequency power of at least very high frequency (VHF) as the high-frequency power; supplying bias power of direct current power and/or high-frequency power of radio-frequency (RF) together with the high-frequency power of VHF to the discharge chamber; and controlling a direct current component of an electric current flowing into an electrode, to which the bias power is supplied, so as to fall within a range of from 0.1 A/m2 to 10 A/m2 in terms of a current density based on the area of an inner wall of the discharge chamber. A good-quality semiconductor layer can be deposited over a large area at a high speed.Type: ApplicationFiled: September 11, 2002Publication date: January 30, 2003Inventors: Yasushi Fujioka, Shotaro Okabe, Masahiro Kanai, Akira Sakai, Tadashi Sawayama, Yuzo Yoda, Takahiro Yajima
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Patent number: 6495392Abstract: A process for producing a semiconductor device such as a photovoltaic element including a solar cell or a photosensor having a photoelectric conversion semiconductor layer formed by sequentially forming a p-type or n-type semiconductor layer composed of a non-single crystalline silicon series semiconductor material, an i-type semiconductor layer composed of a non-single crystalline silicon series semiconductor material, and an n-type or p-type semiconductor layer composed of a non-single crystalline silicon series semiconductor material on a substrate by means of plasma CVD, characterized in that at least one i-type semiconductor as said i-type semiconductor layer is formed in a discharge chamber having a cathode electrode by means of VHF plasma CVD using a silicon-containing raw material gas, wherein a VHF power of a wattage which is two times or less that of a VHF power required for decomposing 100% of said silicon-containing raw material gas is applied to said cathode electrode.Type: GrantFiled: July 23, 2001Date of Patent: December 17, 2002Assignee: Canon Kabushiki KaishaInventors: Akira Sakai, Yasushi Fujioka, Shotaro Okabe, Masahiro Kanai, Tadashi Sawayama, Yuzo Koda, Takahiro Yajima
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Patent number: 6472296Abstract: A process for producing a semiconductor layer by introducing a raw gas into a discharge chamber and supplying high-frequency power to the chamber to decompose the raw gas by discharge, thereby forming a semiconductor layer on a substrate within the discharge chamber, the process comprising the steps of supplying high-frequency power of at least very high frequency (VHF) as the high-frequency power; supplying bias power of direct current power and/or high-frequency power of radio-frequency (RF) together with the high-frequency power of VHF to the discharge chamber; and controlling a direct current component of an electric current flowing into an electrode, to which the bias power is supplied, so as to fall within a range of from 0.1 A/m2 to 10 A/m2 in terms of a current density based on the area of an inner wall of the discharge chamber. A good-quality semiconductor layer can be deposited over a large area at a high speed.Type: GrantFiled: July 26, 2001Date of Patent: October 29, 2002Assignee: Canon Kabushiki KaishaInventors: Yasushi Fujioka, Shotaro Okabe, Masahiro Kanai, Akira Sakai, Tadashi Sawayama, Yuzo Koda, Takahiro Yajima
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Patent number: 6470823Abstract: A film-forming apparatus comprising a vacuum chamber, a power application electrode, a raw material gas introduction portion through which a raw material gas is introduced into the vacuum chamber, and an exhaustion portion through which the vacuum chamber is exhausted, the power application electrode being arranged so as to oppose a substrate for film formation positioned in the vacuum chamber, characterized in that at least said raw material gas introduction portion or the exhaustion portion is provided with an opening adjusting member having a desired thickness for intercepting the plasma, and the power application electrode and the opening adjusting member are arranged to satisfy an equation a or c≧b, with a being a shortest distance between the power application electrode and the opening adjusting member provided at the raw material gas introduction portion, c being a shortest distance between the power application electrode and the opening adjusting member provided at the exhaustion portion, and b beiType: GrantFiled: January 30, 2001Date of Patent: October 29, 2002Assignee: Canon Kabushiki KaishaInventors: Takahiro Yajima, Masahiro Kanai, Yuzo Koda, Takeshi Shishido
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Patent number: 6399411Abstract: A method for forming a non-single-crystal semiconductor thin film and a photovoltaic device using an apparatus, which has a film deposition chamber with a film-forming space surrounded by a film deposition chamber wall and a belt-like substrate. An external chamber surrounding the deposition chamber wall is provided in the apparatus. While the belt-like substrate is moved in a longitudinal direction, a film-forming gas is introduced through a gas supply device into the film-forming space and microwave energy is radiated from a microwave applicator into the film-forming space to induce a microwave plasma, and thereby form a non-single-crystal semiconductor thin film on a surface of the belt-like substrate. A cooling mechanism and a temperature-increasing mechanism covering a part of an outside surface of the deposition chamber wall provide temperature control.Type: GrantFiled: June 15, 2000Date of Patent: June 4, 2002Assignee: Canon Kabushiki KaishaInventors: Tadashi Hori, Shotaro Okabe, Akira Sakai, Yuzo Kohda, Takahiro Yajima
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Patent number: 6368944Abstract: The photovoltaic element of the present invention is a photovoltaic element comprised of a semiconductor-junctioned element, characterized in that the element includes a first electrically conductive type semiconductor layer, a non-crystalline i type semiconductor layer, a microcrystalline i type semiconductor layer and a microcrystalline second electrically conductive type semiconductor layer and is pin-junctioned, and a method of and an apparatus for manufacturing the same are characterized by efficiently and continuously mass-producing the photovoltaic element having an excellent current-voltage characteristic and excellent photoelectric conversion efficiency.Type: GrantFiled: September 18, 2000Date of Patent: April 9, 2002Assignee: Canon Kabushiki KaishaInventors: Shotaro Okabe, Yasushi Fujioka, Masahiro Kanai, Akira Sakai, Tadashi Sawayama, Yuzo Kohda, Tadashi Hori, Takahiro Yajima
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Publication number: 20020039832Abstract: In a discharge space, a substrate 201 and a cathode 206 are disposed a distance d (cm) apart from each other, and gas containing one or more silicon compounds and hydrogen are introduced into the discharge space, and a product Pd of a film forming pressure P (Pa) and d, and a hydrogen flow rate M (SLM) are set so as to meet a relation:Type: ApplicationFiled: July 9, 2001Publication date: April 4, 2002Inventors: Takahiro Yajima, Masahiro Kanai, Shuichiro Sugiyama
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Publication number: 20020022349Abstract: In a semiconductor thin-film formation process comprising feeding a semiconductor thin-film material gas into a discharge space, and applying a high-frequency power thereto to cause plasma to take place and decompose the material gas to form an amorphous semiconductor thin film on a desired substrate, the high-frequency power is applied changing its power density continuously or stepwise from a high power density to a low power density and thereafter again changing the power density continuously or stepwise from a low power density to a high power density, to form a semiconductor thin film made different in film quality in the direction of layer thickness while retaining the same conductivity type This process enables formation of high-quality semiconductor thin films by plasma CVD.Type: ApplicationFiled: May 22, 2001Publication date: February 21, 2002Inventors: Shuichiro Sugiyama, Masahiro Kanai, Takahiro Yajima
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Publication number: 20020016017Abstract: A process for producing a semiconductor device such as a photovoltaic element including a solar cell or a photosensor hating a photoelectric conversion semiconductor layer formed by sequentially forming a p-type or n-type semiconductor layer composed of a non-single crystalline silicon series semiconductor material, an i-type semiconductor layer composed of a non-single crystalline silicon series semiconductor material, and an n-type or p-type semiconductor layer composed of a non-single crystalline silicon series semiconductor material on a substrate by means of plasma CVD, characterized in that at least one i-type semiconductor as said i-type semiconductor layer is formed in a discharge chamber having a cathode electrode by means of VHF plasma CVD using a silicon-containing raw material gas, wherein a VHF power of a wattage which is two times or less that of a VHF power required for decomposing 100% of said silicon-containing raw material gas is applied to said cathode electrode.Type: ApplicationFiled: July 23, 2001Publication date: February 7, 2002Inventors: Akira Sakai, Yasushi Fujioka, Shotaro Okabe, Masahiro Kanai, Tadashi Sawayama, Yuzo Koda, Takahiro Yajima
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Publication number: 20020006476Abstract: A film-forming apparatus by means of plasma CVD, comprising at least a vacuum chamber, a power application electrode for introducing a discharging power into said vacuum chamber, and a raw material gas supply means for supplying a film-forming raw material gas into said vacuum chamber, said power application electrode being arranged in said vacuum chamber so as to oppose to a substrate arranged in said vacuum chamber, characterized in that said power application electrode has a reinforcing member or said power application electrode comprises a power application electrode with no reinforcing member which has a thickness which is greater than a distance between said substrate and said power application electrode. A film-forming method using said film-forming apparatus.Type: ApplicationFiled: December 4, 2000Publication date: January 17, 2002Inventors: Takahiro Yajima, Masahiro Kanai, Takeshi Shishido
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Publication number: 20020001924Abstract: The invention provides a process for producing a semiconductor layer by introducing a raw gas into a discharge chamber and supplying high-frequency power to the chamber to decompose the raw gas by discharge, thereby forming a semiconductor layer on a substrate within the discharge chamber, the process comprising the steps of supplying high-frequency power of at least very high frequency (VHF) as the high-frequency power; supplying bias power of direct current power and/or high-frequency power of radio-frequency (RF) together with the high-frequency power of VHF to the discharge chamber; and controlling a direct current component of an electric current flowing into an electrode, to which the bias power is supplied, so as to fall within a range of from 0.1 A/m2 to 10 A/m2 in terms of a current density based on the area of an inner wall of the discharge chamber. A good-quality semiconductor layer can be deposited over a large area at a high speed.Type: ApplicationFiled: July 26, 2001Publication date: January 3, 2002Inventors: Yasushi Fujioka, Shotaro Okabe, Masahiro Kanai, Akira Sakai, Tadashi Sawayama, Yuzo Koda, Takahiro Yajima
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Publication number: 20010029893Abstract: A deposited film forming apparatus is provided which has a power applying electrode disposed above a flat plate type base member grounded, in a vacuum chamber, and a power source for supplying a power to the power applying electrode, the deposited film forming apparatus being constructed to supply the power from the power source to the power applying electrode so as to generate a plasma in a discharge space between the power applying electrode and a substrate disposed in opposition to the power applying electrode in the vacuum chamber and serving as an electrode in a pair with the power applying electrode, thereby decomposing a source gas introduced into the vacuum chamber to form a deposited film on the substrate, wherein the power applying electrode is fixed to the base member with the power applying electrode being isolated from the base member. A deposited film forming method using the apparatus is also provided.Type: ApplicationFiled: January 31, 2001Publication date: October 18, 2001Inventors: Takahiro Yajima, Masahiro Kanai, Takeshi Shishido
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Publication number: 20010025601Abstract: A film-forming apparatus comprising a vacuum chamber, a power application electrode, a raw material gas introduction portion through which a raw material gas is introduced into said vacuum chamber, and an exhaustion portion through which said vacuum chamber is exhausted, said power application electrode being arranged so as to oppose a substrate for film formation positioned in said vacuum chamber, characterized in that at least said raw material gas introduction portion or said exhaustion portion is provided with an opening adjusting member having a desired thickness for intercepting said plasma, and said power application electrode and said opening adjusting member are arranged to satisfy an equation a or c≧b.Type: ApplicationFiled: January 30, 2001Publication date: October 4, 2001Inventors: Takahiro Yajima, Masahiro Kanai, Yuzo Koda, Takeshi Shishido
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Publication number: 20010022991Abstract: A two-layer structured electric power application electrode including a non-split electrode consisting of a single planar plate and six split electrodes arranged on the non-split electrode so as to be electrically in contact with the non-split electrode is arranged on the upper side of a discharge chamber provided within a vacuum container such that the power application electrode faces a strip substrate in parallel. The split electrodes are arranged in such a manner as to form a planar plane, and the distance between the surfaces of the split electrodes facing the strip substrate and the strip substrate is uniform. The total area of the surfaces of the split electrodes facing the strip substrate is the same as the area of the non-split electrode on which the split electrodes are mounted. This improves the uniformity in plasma generated in the apparatus for forming a deposited film and enables cutting-down of the costs required to form deposited films.Type: ApplicationFiled: January 24, 2001Publication date: September 20, 2001Inventors: Takeshi Shishido, Masahiro Kanai, Yuzo Koda, Takahiro Yajima
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Publication number: 20010022996Abstract: The surface shape of a power-applying electrode is altered in agreement with the curving of a substrate so that the electrode-substrate distance can be kept at a constant value. This enables formation of thin films having uniform film thickness in the substrate width direction even when the electrode-substrate distance is shortened in order to make film formation rate higher in deposited-film formation apparatus of a roll-to-roll system.Type: ApplicationFiled: January 26, 2001Publication date: September 20, 2001Inventors: Takahiro Yajima, Masahiro Kanai, Takeshi Shishido
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Patent number: 6287943Abstract: The invention provides a process for producing a semiconductor layer by introducing a raw gas into a discharge chamber and supplying high-frequency power to the chamber to decompose the raw gas by discharge, thereby forming a semiconductor layer on a substrate within the discharge chamber, the process comprising the steps of supplying high-frequency power of at least very high frequency (VHF) as the high-frequency power; supplying bias power of direct current power and/or high-frequency power of radio-frequency (RF) together with the high-frequency power of VHF to the discharge chamber; and controlling a direct current component of an electric current flowing into an electrode, to which the bias power is supplied, so as to fall within a range of from 0.1 A/m2 to 10 A/m2 in terms of a current density based on the area of an inner wall of the discharge chamber. A good-quality semiconductor layer can be deposited over a large area at a high speed.Type: GrantFiled: July 30, 1999Date of Patent: September 11, 2001Assignee: Canon Kabushiki KaishaInventors: Yasushi Fujioka, Shotaro Okabe, Masahiro Kanai, Akira Sakai, Tadashi Sawayama, Yuzo Koda, Takahiro Yajima