Patents by Inventor Katsumi Nakagawa

Katsumi Nakagawa 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).

  • Publication number: 20020005158
    Abstract: Provided are a liquid phase growth method of silicon crystal comprising a step of injecting a source gas containing at least silicon atoms into a solvent to decompose the source gas and, simultaneously therewith, dissolving the silicon atoms into the solvent, thereby supplying the silicon atoms into the solvent, and a step of dipping or contacting a substrate into or with the solvent, thereby growing a silicon crystal on the substrate; and a method of producing a solar cell utilizing the aforementioned method. Also provided is a liquid phase growth apparatus of a silicon crystal comprising means for holding a solvent in which silicon atoms are dissolved, and means for dipping or contacting a substrate into or with the solvent, the apparatus further comprising means for injecting a source gas containing at least silicon atoms into the solvent.
    Type: Application
    Filed: December 10, 1998
    Publication date: January 17, 2002
    Inventors: SHOJI NISHIDA, KATSUMI NAKAGAWA, NORITAKA UKIYO, MASAAKI IWANE
  • Publication number: 20010051387
    Abstract: The method of the present invention of growing single crystal silicon in a liquid phase comprises preparing a melt by dissolving a solid of silicon containing boron, aluminum, phosphorus or arsenic at a predetermined concentration into indium melted in a carbon boat or a quartz crucible, supersaturating the melt, and submerging a substrate into the melt, thereby growing a silicon crystal containing a dopant element. This method can provide a method of growing a thin film of crystalline silicon having a high crystallinity and a dopant concentration favorably controlled, thereby serving for mass production of inexpensive solar cells which have high performance as well as image displays which have high contrast and are free from color ununiformity.
    Type: Application
    Filed: November 24, 1998
    Publication date: December 13, 2001
    Inventors: KATSUMI NAKAGAWA, SHOJI NISHIDA, NORITAKA UKIYO, MASAAKI IWANE
  • Publication number: 20010041423
    Abstract: A method for transferring a porous layer includes forming a porous layer on one side of a crystalline silicon member by anodization, fixing a supporting substrate onto the surface of the porous layer, and applying force to any one of the supporting substrate and the porous layer, whereby at least part of the porous layer is cleaved from the crystalline silicon member and is transferred onto the supporting substrate. The crystalline silicon member can be recycled and this method is suitable for mass production of semiconductor devices or solar batteries at low cost.
    Type: Application
    Filed: January 26, 2001
    Publication date: November 15, 2001
    Inventors: Shoji Nishida, Katsumi Nakagawa, Takao Yonehara, Kiyofumi Sakaguchi
  • Publication number: 20010023702
    Abstract: The solar cell module of the present invention comprises a plurality of unit cells connected in series, each of the unit cells comprising in this order an electrode, a first semiconductor layer having a first conductivity type and a second semiconductor layer having a second conductivity type, wherein the electrode has a region not covered with the first semiconductor layer, wherein the second semiconductor layer has a main region and a subregion which are separated by a groove, wherein the main region of the second semiconductor layer in one unit cell of the unit cells is electrically connected to the region of the electrode not covered with the first semiconductor layer in another unit cell adjacent to the one unit cell, and wherein the region of the electrode not covered with the first semiconductor layer in the one unit cell is electrically connected to the subregion of the second semiconductor layer in the another unit cell, whereby it is possible to simplify a step of forming a bypass diode and the pres
    Type: Application
    Filed: February 23, 2001
    Publication date: September 27, 2001
    Inventors: Katsumi Nakagawa, Shoji Nishida, Yukiko Iwasaki
  • Publication number: 20010018949
    Abstract: Provided is a method of producing a semiconductor thin film wherein while a semiconductor thin film formed on a substrate is supported on a curved surface of a support member having the curved surface, the support member is rotated, thereby peeling the semiconductor thin film away from the substrate. Also provided is a method of producing a semiconductor thin film having the step of peeling a semiconductor thin film formed on a substrate away from the substrate, wherein the peeling step is carried out after the substrate is secured on a substrate support member without an adhesive. These provide the method of peeling the semiconductor thin film away from the substrate without damage and the method of holding the substrate without contamination.
    Type: Application
    Filed: March 21, 2001
    Publication date: September 6, 2001
    Inventors: Masaki Mizutani, Isao Tanikawa, Katsumi Nakagawa, Tatsumi Shoji, Noritaka Ukiyo, Yukiko Iwasaki
  • Patent number: 6258698
    Abstract: A process for producing a semiconductor substrate is provided which comprises a first step of anodizing a surface of a first substrate to form a porous layer on the surface, a second step of simultaneously forming a semiconductor layer on the surface of the porous layer and a semiconductor layer on a surface of the first substrate on its side opposite to the porous layer side, a third step of bonding the surface of the semiconductor layer formed on the surface of the porous layer to a surface of a second substrate, and a fourth step of separating the first substrate and the second substrate at the part of the porous layer to transfer to the second substrate the semiconductor layer formed on the surface of the porous layer, thereby providing the semiconductor layer on the surface of the second substrate. This makes it possible to produce semiconductor substrates at a low cost while making good use of expensive substrate materials.
    Type: Grant
    Filed: March 24, 1998
    Date of Patent: July 10, 2001
    Assignee: Canon Kabushiki Kaisha
    Inventors: Yukiko Iwasaki, Katsumi Nakagawa, Takao Yonehara, Shoji Nishida, Kiyofumi Sakaguchi
  • Patent number: 6258666
    Abstract: Provided is a method of producing a semiconductor thin film wherein while a semiconductor thin film formed on a substrate is supported on a curved surface of a support member having the curved surface, the support member is rotated, thereby peeling the semiconductor thin film away from the substrate. Also provided is a method of producing a semiconductor thin film having the step of peeling a semiconductor thin film formed on a substrate away from the substrate, wherein the peeling step is carried out after the substrate is secured on a substrate support member without an adhesive. These provide the method of peeling the semiconductor thin film away from the substrate without damage and the method of holding the substrate without contamination.
    Type: Grant
    Filed: June 15, 1999
    Date of Patent: July 10, 2001
    Assignee: Canon Kabushiki Kaisha
    Inventors: Masaki Mizutani, Isao Tanikawa, Katsumi Nakagawa, Tatsumi Shoji, Noritaka Ukiyo, Yukiko Iwasaki
  • Patent number: 6258702
    Abstract: A film-forming method for forming a cuprous oxide film includes the steps of immersing a substrate having at least an electrically conductive surface in a solution containing copper ion and nitrate ion which are coexistent therein, and causing deposition of the cuprous oxide film on the electrically conductive surface of the substrate by way of cathodic reaction. A process for producing a semiconductor device such as a solar cell or a rectifier also is provided using the film-forming method.
    Type: Grant
    Filed: November 12, 1998
    Date of Patent: July 10, 2001
    Assignee: Canon Kabushiki Kaisha
    Inventors: Katsumi Nakagawa, Kozo Arao, Yukiko Iwasaki
  • Patent number: 6248948
    Abstract: A solar cell module comprises a plurality of unit cells connected in series, each of the unit cells comprising in this order an electrode, a first semiconductor layer having a first conductivity type and a second semiconductor layer having a second conductivity type. The electrode has a region not covered with the first semiconductor layer. The second semiconductor layer has a main region and a subregion which are separated by a groove. The main region of the second semiconductor layer in one unit cell is electrically connected to the region of the electrode not covered with the first semiconductor layer in another unit cell adjacent to the one unit cell. The region of the electrode not covered with the first semiconductor layer in the one unit cell is electrically connected to the subregion of the second semiconductor layer in the another unit cell. With this structure, it is possible to simplify the formation of a bypass diode and therefore provide a solar cell module with high reliability at a low cost.
    Type: Grant
    Filed: May 13, 1999
    Date of Patent: June 19, 2001
    Assignee: Canon Kabushiki Kaisha
    Inventors: Katsumi Nakagawa, Shoji Nishida, Yukiko Iwasaki
  • Patent number: 6231667
    Abstract: A liquid phase growth apparatus of a dipping system has a plurality of liquid phase growth chambers and liquid phase growth operations of semiconductors are carried out on a plurality of substrates in the growth chambers. Another liquid phase growth apparatus of the dipping system has a liquid phase growth chamber and an annealing chamber, and is constructed in such structure that liquid phase growth of a semiconductor on one substrate is carried out in the liquid phase growth chamber and that an annealing operation of another substrate different from the aforementioned substrate is carried out in the annealing chamber. Another liquid phase growth apparatus of the dipping system has a liquid phase growth chamber and an annealing chamber, and is constructed in such structure that a semiconductor material is dissolved into a solvent in the liquid phase growth chamber and that the annealing operation of a substrate is carried out in the annealing chamber.
    Type: Grant
    Filed: November 27, 1998
    Date of Patent: May 15, 2001
    Assignee: Canon Kabushiki Kaisha
    Inventors: Masaaki Iwane, Isao Tanikawa, Katsumi Nakagawa, Tatsumi Shoji, Shoji Nishida, Noritaka Ukiyo
  • Patent number: 6211038
    Abstract: A method for manufacturing a thin-film crystalline solar cell includes the steps of (i) forming a porous layer including a large number of fine pores in a surface portion of a crystalline substrate, (ii) transforming a part of the porous layer including the surface thereof into a smooth layer which does not include fine pores by providing the porous layer with excitation energy, and (iii) peeling the smooth layer from the substrate. The excitation energy is provided, for example, by performing heat treatment in a hydrogen atmosphere, irradiating with light having a wavelength equal to or less than 600 nm, or irradiating with an electron beam. It is thereby possible to form a thin-film crystalline semiconductor layer on an inexpensive and flexible substrate by simple processes.
    Type: Grant
    Filed: March 25, 1998
    Date of Patent: April 3, 2001
    Assignee: Canon Kabushiki Kaisha
    Inventors: Katsumi Nakagawa, Takao Yonehara, Shoji Nishida, Kiyofumi Sakaguchi, Yukiko Iwasaki
  • Patent number: 6190937
    Abstract: To accomplish both higher performance of a crystal and lower cost in a semiconductor member, and to produce a solar cell having a high efficiency and a flexible shape at low cost, the semiconductor member is produced by the following steps, (a) forming a porous layer in the surface region of a substrate, (b) immersing the porous layer into a melting solution in which elements for forming a semiconductor layer to be grown is dissolved, under a reducing atmosphere at a high temperature, to grow a crystal semiconductor layer on the surface of the porous layer, (c) bonding another substrate onto the surface of the substrate on which the porous layer and the semiconductor layer are formed and (d) separating the substrate from the another substrate at the porous layer.
    Type: Grant
    Filed: December 29, 1997
    Date of Patent: February 20, 2001
    Assignee: Canon Kabushiki Kaisha
    Inventors: Katsumi Nakagawa, Takao Yonehara, Shoji Nishida, Kiyofumi Sakaguchi
  • Patent number: 6110347
    Abstract: A method for forming an indium oxide film on an electrically conductive substrate by immersing the substrate and a counter electrode in an aqueous solution containing at least nitrate and indium ions and flowing an electric current between the substrate and the couter electrode, thereby causing indium oxide film formation on the substrate, is provided. A substrate for a semiconductor element and a photovoltaic element produced using the film forming method are also provided. An aqueous solution for the formation of an indium oxide film by an electroless deposition process, containing at least nitrate and indium ions and tartrate, is also disclosed. A film-forming method for the formation of an indium oxide film on a substrate by an electroless deposition process, using the aqueous solution, and a substrate for a semiconductor element and a photovoltaic element produced using the film-forming method are further provided.
    Type: Grant
    Filed: October 15, 1998
    Date of Patent: August 29, 2000
    Assignee: Canon Kabushiki Kashia
    Inventors: Kozo Arao, Katsumi Nakagawa, Yukiko Iwasaki
  • Patent number: 6080928
    Abstract: An insulating film is formed on a conductive substrate, a conductor film is deposited on the insulating film, and a plurality of first electrodes are formed by forming at least one groove in the conductor film. A transparent layer is so formed as to cover the first electrodes and bury the groove formed in the conductor film. A photovoltaic layer is formed on the transparent layer, and an ITO film is deposited on the photovoltaic layer. A plurality of second electrodes are formed by forming at least one groove in the ITO film in parallel with the groove formed in the conductor film. A groove or a hole extending through at least the photovoltaic layer is formed between the two parallel grooves, and a conductive material is filled in this groove or hole, thereby electrically connecting the first and second electrodes adjacent to each other. Since the groove for separating the adjacent first electrodes is buried with the transparent layer, no defects occur due to the step in the groove.
    Type: Grant
    Filed: September 9, 1996
    Date of Patent: June 27, 2000
    Assignee: Canon Kabushiki Kaisha
    Inventor: Katsumi Nakagawa
  • Patent number: 6061977
    Abstract: A photovoltaic device comprises a metal with a smooth surface; a transparent conductive layer formed on the smooth surface; and a photoelectric conversion layer formed on the transparent conductive layer. The transparent conductive layer has an irregular surface at a side opposite to the smooth surface.
    Type: Grant
    Filed: April 16, 1998
    Date of Patent: May 16, 2000
    Assignee: Canon Kabushiki Kaisha
    Inventors: Noboru Toyama, Katsumi Nakagawa
  • Patent number: 5986204
    Abstract: By using an improved back reflecting layer, a photovoltaic cell having excellent migration resistance and a high photoelectric conversion efficiency is provided at high productivity. The photovoltaic cell includes a metal layer comprising a silver-aluminum alloy having a content of silver equal to or less than 30 atomic percent, the rest being aluminum, or a metal layer comprising a copper-aluminum alloy having a content of copper between 30 and 50 atomic percent, the rest being aluminum. It is preferable to form these layers at a relatively low temperature by sputtering, particularly at a temperature equal to or less than 110.degree. C. for the silver-aluminum alloy and at a temperature equal to or less than 120.degree. C. for the copper-aluminum alloy.
    Type: Grant
    Filed: March 19, 1997
    Date of Patent: November 16, 1999
    Assignee: Canon Kabushiki Kaisha
    Inventors: Yukiko Iwasaki, Katsumi Nakagawa, Kozo Arao
  • Patent number: 5981864
    Abstract: A metal layer (102) is formed on an insulating substrate (101), and a first transparent conductive layer (103) containing fluorine is formed on the metal layer (102). The metal layer (102) and the transparent conductive layer (103) are electrically divided by laser irradiation to prepare lower electrodes. A photoelectric conversion layer (105) is formed on the first transparent conductive layer (103), and a second transparent conductive layer (106) is formed on the photoelectric conversion layer (105). The transparent conductive layer (106) is electrically divided by laser irradiation to form upper electrodes. Then, lower and upper electrodes adjacent to each other are electrically connected by laser irradiation. According to this method of fabricating a photovoltaic element array, the resistivity of a connecting portion which electrically connects the lower and upper electrodes can be decreased.
    Type: Grant
    Filed: March 14, 1997
    Date of Patent: November 9, 1999
    Assignee: Canon Kabushiki Kaisha
    Inventors: Masaki Mizutani, Katsumi Nakagawa
  • Patent number: 5981867
    Abstract: A photovoltaic device comprises a metal with a smooth surface; a transparent conductive layer formed on the smooth surface; and a photoelectric conversion layer formed on the transparent conductive layer. The transparent conductive layer has an irregular surface at a side opposite to the smooth surface.
    Type: Grant
    Filed: April 16, 1998
    Date of Patent: November 9, 1999
    Assignee: Canon Kabushiki Kaisha
    Inventors: Noboru Toyama, Katsumi Nakagawa
  • Patent number: 5885725
    Abstract: A photovoltaic device comprises a metal with a smooth surface; a transparent conductive layer formed on the smooth surface; and a photoelectric conversion layer formed on the transparent conductive layer. The transparent conductive layer has an irregular surface at a side opposite to the smooth surface.
    Type: Grant
    Filed: August 28, 1996
    Date of Patent: March 23, 1999
    Assignee: Canon Kabushiki Kaisha
    Inventors: Noboru Toyama, Katsumi Nakagawa
  • Patent number: 5874350
    Abstract: A method for forming a functional silicon- or germanium-containing amorphous deposited film on a substrate which comprises a film-forming chamber having a film-forming space, a substrate holder and an electric heater for positioning the substrate in the film-forming chamber, an exhaust pipe in fluid communication with the film-forming chamber, a first gas-introducing portion for providing an active species (H), having an activation space for generating the active species (H), a microwave discharge supply source and a passage for providing a gaseous hydrogen-containing material into the activation space in order to produce the active species (H), a second gas-introducing portion for providing a gaseous silicon- or germanium-containing material (X), capable of reacting with the active species (H) to form a reaction product (HX) that is capable of forming the functional deposited film on the substrate, and a transportation path having a mixing space and a second microwave discharge energy supply source for promo
    Type: Grant
    Filed: October 13, 1994
    Date of Patent: February 23, 1999
    Assignee: Canon Kabushiki Kaisha
    Inventor: Katsumi Nakagawa