Patents by Inventor Tadahiro Kato

Tadahiro Kato 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: 20090170406
    Abstract: The present invention is a wafer production method at least comprising a chamfering step of chamfering a wafer sliced from an ingot using a grindstone for chamfering, and a step of obtaining a product wafer thinner than the chamfered wafer by performing at least one or more than one of the following processes on the chamfered wafer: flattening, etching, and polishing, the method at least comprising a correction step of chamfering a dummy wafer equivalent in thickness to the product wafer, measuring the chamfered dummy wafer for its chamfered shape, and correcting the shape of the grindstone for chamfering based on the measured chamfered shape of the dummy wafer, at least before the chamfering step, thereby chamfering the wafer sliced from the ingot using the grindstone for chamfering having its shape corrected. Thus, it is possible to provide a wafer production method allowing a product wafer with a desired chamfered shape to be obtained in a short period of time.
    Type: Application
    Filed: May 11, 2007
    Publication date: July 2, 2009
    Applicant: SHIN-ETSU HANDOTAI CO., LTD.
    Inventor: Tadahiro Kato
  • Patent number: 7507146
    Abstract: The present invention is a method for producing a semiconductor wafer, comprising: at least a double-side polishing step; and a chamfered-portion polishing step; wherein as a first chamfered-portion polishing step, at least, a chamfered portion of the wafer is polished so that a chamfered surface of each of main surface sides in the chamfered portion is in contact with a polishing pad; then the double-side polishing is performed; as a second chamfered-portion polishing step, at least, the chamfered portion of the wafer is polished so that an end surface of the chamfered portion is in contact with a polishing pad and so that both main surfaces of the wafer are not in contact with a polishing pad. Thereby, when a semiconductor wafer is produced, scratch and such generated in the chamfered portion in a double-side polishing process can be removed and, excessive polishing in a peripheral portion of a main surface can be prevented from being caused in polishing a chamfered portion.
    Type: Grant
    Filed: October 12, 2005
    Date of Patent: March 24, 2009
    Assignee: Shin-Etsu Handotai Co., Ltd.
    Inventors: Tadahiro Kato, Masayoshi Sekizawa, Mamoru Okada, Hisashi Kijima
  • Publication number: 20080113510
    Abstract: There is provided a semiconductor wafer fabricating method comprising at least: a double-side polishing step of mirror-polishing a front surface and a back surface of a semiconductor wafer; and a mirror edge polishing step of mirror-polishing a chamfered part of the double-side-polished semiconductor wafer, wherein a protection film made of a resin which suppresses polishing is formed on the front surface or both the front and back surfaces of the semiconductor wafer after the double-side polishing step, then the mirror edge polishing step is carried out, and thereafter the protection film made of a resin is removed. As a result, it is possible to provide a step of eliminating an increase in a cost due to, e.g.
    Type: Application
    Filed: February 7, 2006
    Publication date: May 15, 2008
    Applicant: SHIN-ETSU HANDOTAI CO., LTD.
    Inventors: Tadahiro Kato, Hideo Kudo
  • Publication number: 20080096474
    Abstract: The present invention is a method for producing a semiconductor wafer, comprising: at least a double-side polishing step; and a chamfered-portion polishing step; wherein as a first chamfered-portion polishing step, at least, a chamfered portion of the wafer is polished so that a chamfered surface of each of main surface sides in the chamfered portion is in contact with a polishing pad; then the double-side polishing is performed; as a second chamfered-portion polishing step, at least, the chamfered portion of the wafer is polished so that an end surface of the chamfered portion is in contact with a polishing pad and so that both main surfaces of the wafer are not in contact with a polishing pad. Thereby, when a semiconductor wafer is produced, scratch and such generated in the chamfered portion in a double-side polishing process can be removed and, excessive polishing in a peripheral portion of a main surface can be prevented from being caused in polishing a chamfered portion.
    Type: Application
    Filed: October 12, 2005
    Publication date: April 24, 2008
    Applicant: SHIN-ETSU HANDOTAI CO., LTD.
    Inventors: Tadahiro Kato, Masayoshi Sekizawa, Mamoru Okada, Hisashi Kijima
  • Patent number: 7332437
    Abstract: There is provided a method for processing a semiconductor wafer subjected to a chamfering process, a lapping process, an etching process, and a mirror-polishing process, wherein acid etching is performed after alkaline etching as the etching process, and the acid etching is performed with an acid etchant composed of hydrofluoric acid, nitric acid, phosphoric acid, and water, a method for processing a semiconductor wafer subjected to a chamfering process, a surface grinding process, an etching process, and a mirror-polishing process, wherein the etching process is performed as described above, and a method for processing a semiconductor wafer subjected to a flattening process, an etching process, and a mirror-polishing process, wherein the etching process is performed as described above, a back surface polishing process is performed after the acid etching as the mirror-polishing process, and then a front surface polishing process is performed.
    Type: Grant
    Filed: June 25, 2001
    Date of Patent: February 19, 2008
    Assignee: Shin-Etsu Handotai Co., Ltd.
    Inventors: Takashi Nihonmatsu, Masahiko Yoshida, Yoshinori Sasaki, Masahito Saitoh, Toshiaki Takaku, Tadahiro Kato
  • Patent number: 6883342
    Abstract: There is provided a multiform gas heat pump type of air conditioning system having: a plurality of indoor units that are each provided with an indoor heat exchanger and that perform a heat exchange between air inside a room and refrigerant; an outdoor unit provided with a compressor driven by a gas engine and an outdoor heat exchanger for performing a heat exchange between outside air and the refrigerant; and a split flow control unit for controlling a flow direction of the refrigerant in each of the indoor units and for performing a selection switching between cooling and heating operations. The outdoor heat exchanger that switches selection between cooling and heating operations is divided into a plurality of units that are connected in parallel and there is also provided a refrigerant supply switching means that controls the refrigerant flow in each of the divided portions of the outdoor heat exchanger.
    Type: Grant
    Filed: June 21, 2002
    Date of Patent: April 26, 2005
    Assignee: Mitsubishi Heavy Industries, Ltd.
    Inventors: Tadahiro Kato, Tsukasa Kasagi
  • Patent number: 6787797
    Abstract: In order to improve the productivity or production yield of chips in the process for device fabrication, the present invention provides a wafer or an apparatus of process for fabricating semiconductor devices having the backside of the wafer or the surface of a wafer holding means adjusted so as to have a distribution in contact surface density between the surface of the wafer holding means and the backside of the wafer when the semiconductor wafer is held on the wafer holding means in the process for fabricating devices.
    Type: Grant
    Filed: April 22, 2002
    Date of Patent: September 7, 2004
    Assignee: Shin-Etsu Handotai Co., Ltd.
    Inventors: Kiyoshi Demizu, Tadahiro Kato, Shigeyoshi Netsu
  • Patent number: 6726525
    Abstract: A double side grinding apparatus comprises a pair of grinding wheels (4), work rotating device (1) and moving device (2).
    Type: Grant
    Filed: August 28, 2001
    Date of Patent: April 27, 2004
    Assignees: Shin-Estu Handotai Co., Ltd., Koy Machine Industries Co., Ltd.
    Inventors: Tadahiro Kato, Shunichi Ikeda, Kenji Ohkura
  • Patent number: 6660337
    Abstract: A decorative film for use in plastics molding, said decorative film being a laminate film prepared by outwardly and successively laminating a polyolefin film layer, a primer layer, optionally a topcoating layer and a releasable layer, said primer layer being a coating film formed from an isocyanate-curing type resin composition containing (A) a hydroxyl group-containing resin having a hydroxyl number of 30 to 200 KOH mg/g on an average and a weight average molecular weight of 1000 to 80000, (B) a polyolefin based resin and (C) a (blocked)polyisocyanate compound in such mixing amounts that a number of the isocyanate group in the component (C) is in the range of 0.1 to 0.9 per one hydroxyl group in the component (A) and that the component (B) is in the range of 1 to 90% by weight based on a total weight of the components (A), (B) and (C), and having a static glass transition temperature of 20 to 70° C., an elongation of 10% or more and a tensile strength of 0.
    Type: Grant
    Filed: May 15, 2002
    Date of Patent: December 9, 2003
    Assignee: Kansai Paint Co., Ltd.
    Inventors: Naoya Haruta, Tadahiro Kato, Takesi Tomiyama, Koichi Seike
  • Patent number: 6652358
    Abstract: In a double side simultaneous grinding machine, in which a plate-like workpiece is held and ground simultaneously on both a front surface and a back surface using a pair of grinding stones provided oppositely at both sides of the workpiece, a relative position between at least one of the center of thickness of the plate-like workpiece and the center of the holding means for holding the workpiece, and the center between stone surfaces of the pair of grinding stones is controlled during grinding. In a double side simultaneous grinding method, the generation of warpage of the plate-like workpiece is suppressed and degradation of warpage is prevented. Thereby, the plate-like workpiece can be processed to have high flatness on both sides. Further, the plate-like workpiece can be ground while a degree of warpage is controlled so that the workpiece is processed to have a warpage of a desired degree.
    Type: Grant
    Filed: December 29, 2000
    Date of Patent: November 25, 2003
    Assignee: Shin-Etsu Handotai Co., Ltd.
    Inventors: Shunichi Ikeda, Sadayuki Okuni, Tadahiro Kato
  • Publication number: 20030171075
    Abstract: There is provided a method for processing a semiconductor wafer subjected to a chamfering process, a lapping process, an etching process, and a mirror-polishing process, wherein acid etching is performed after alkaline etching as the etching process, and the acid etching is performed with an acid etchant composed of hydrofluoric acid, nitric acid, phosphoric acid, and water, a method for processing a semiconductor wafer subjected to a chamfering process, a surface grinding process, an etching process, and a mirror-polishing process, wherein the etching process is performed as described above, and a method for processing a semiconductor wafer subjected to a flattening process, an etching process, and a mirror-polishing process, wherein the etching process is performed as described above, a back surface polishing process is performed after the acid etching as the mirror-polishing process, and then a front surface polishing process is performed.
    Type: Application
    Filed: December 27, 2002
    Publication date: September 11, 2003
    Inventors: Takashi Nihonmatsu, Masahiko Yoshida, Yoshinori Sasaki, Masahito Saitoh, Toshiaki Takaku, Tadahiro Kato
  • Publication number: 20030039839
    Abstract: A decorative film for use in plastics molding, said decorative film being a laminate film prepared by outwardly and successively laminating a polyolefin film layer, a primer layer, optionally a topcoating layer and a releasable layer, said primer layer being a coating film formed from an isocyanate-curing type resin composition containing (A) a hydroxyl group-containing resin having a hydroxyl number of 30 to 200 KOH mg/g on an average and a weight average molecular weight of 1000 to 80000, (B) a polyolefin based resin and (C) a (blocked)polyisocyanate compound in such mixing amounts that a number of the isocyanate group in the component (C) is in the range of 0.1 to 0.9 per one hydroxyl group in the component (A) and that the component (B) is in the range of 1 to 90% by weight based on a total weight of the components (A), (B) and (C), and having a static glass transition temperature of 20 to 70° C., an elongation of 10% or more and a tensile strength of 0.
    Type: Application
    Filed: May 15, 2002
    Publication date: February 27, 2003
    Inventors: Naoya Haruta, Tadahiro Kato, Takesi Tomiyama, Koichi Seike
  • Publication number: 20020194857
    Abstract: There is provided a multiform gas heat pump type of air conditioning system having: a plurality of indoor units that are each provided with an indoor heat exchanger and that perform a heat exchange between air inside a room and refrigerant; an outdoor unit provided with a compressor driven by a gas engine and an outdoor heat exchanger for performing a heat exchange between outside air and the refrigerant; and a split flow control unit for controlling a flow direction of the refrigerant in each of the indoor units and for performing a selection switching between cooling and heating operations. The outdoor heat exchanger that switches selection between cooling and heating operations is divided into a plurality of units that are connected in parallel and there is also provided a refrigerant supply switching means that controls the refrigerant flow in each of the divided portions of the outdoor heat exchanger.
    Type: Application
    Filed: June 21, 2002
    Publication date: December 26, 2002
    Applicant: MITSUBISHI HEAVY INDUSTRIES, LTD.
    Inventors: Tadahiro Kato, Tsukasa Kasagi
  • Patent number: 6491836
    Abstract: A method for producing a semiconductor wafer that yields a wafer having high flatness and back surface characteristics to address problems concerning the back surface of a wafer produced by the conventional surface grinding/double side polishing method and observed during the production process. The method comprises flattening both sides of the wafer by surface grinding means, eliminating a mechanically damaged layer by an etching treatment, and then subjecting a front surface of the wafer to a single side polishing treatment, wherein a back surface of the wafer has glossiness in a range of 20-80%.
    Type: Grant
    Filed: June 26, 2000
    Date of Patent: December 10, 2002
    Assignee: Shin-Etsu Handotai Co., Ltd.
    Inventors: Tadahiro Kato, Sadayuki Okuni, Shunichi Ikeda, Keiichi Okabe, Hisashi Oshima
  • Publication number: 20020167006
    Abstract: In order to improve the productivity or production yield of chips in the process for device fabrication, the present invention provides a wafer or an apparatus of process for fabricating semiconductor devices having the backside of the wafer or the surface of a wafer holding means adjusted so as to have a distribution in contact surface density between the surface of the wafer holding means and the backside of the wafer when the semiconductor wafer is held on the wafer holding means in the process for fabricating devices.
    Type: Application
    Filed: April 22, 2002
    Publication date: November 14, 2002
    Inventors: Kiyoshi Demizu, Tadahiro Kato, Shigeyoshi Netsu
  • Patent number: 6444317
    Abstract: A decorative film for use in plastics molding, the decorative film being a laminate film prepared by outwardly and successively laminating a polyolefin film layer, a primer layer, optionally a topcoating layer and a releasable layer, the primer layer being a coating film formed from an isocyanate-curing type resin composition containing (A) a hydroxyl group-containing resin having a hydroxyl number of 30 to 200 KOH mg/g on an average and a weight average molecular weight of 1000 to 80000, (B) a polyolefin based resin and (C) a (blocked) polyisocyanate compound in such mixing amounts that a number of the isocyanate group in the component (C) is in the range of 0.1 to 0.9 per one hydroxyl group in the component (A) and that the component (B) is in the range of 1 to 90% by weight based on a total weight of the components (A), (B) and (C), and having a static glass transition temperature of 20 to 70° C., an elongation of 10% or more and a tensile strength of 0.
    Type: Grant
    Filed: August 6, 1999
    Date of Patent: September 3, 2002
    Assignee: Kansai Paint Co., Ltd.
    Inventors: Naoya Haruta, Tadahiro Kato, Takesi Tomiyama, Koichi Seike
  • Patent number: 6432837
    Abstract: A method of processing a semiconductor wafer sliced from a monocrystalline ingot comprises at least the steps of chamfering, lapping, etching, mirror-polishing, and cleaning. In the etching step, alkali etching is first performed and then acid etching, preferably reaction-controlled acid etching, is performed. The etching amount of the alkali etching is greater than the etching amount of the acid etching. Alternatively, in the etching step, reaction-controlled acid etching is first performed and then diffusion-controlled acid etching is performed. The etching amount of the reaction-controlled acid etching is greater than the etching amount of the diffusion-controlled acid etching.
    Type: Grant
    Filed: February 7, 2001
    Date of Patent: August 13, 2002
    Assignee: Shin-Etsu Handotai Co., Ltd.
    Inventors: Takashi Nihonmatsu, Seiichi Miyazaki, Masahiko Yoshida, Hideo Kudo, Tadahiro Kato
  • Patent number: 6358117
    Abstract: A surface grinding method is provided by which grinding striations are produced so that the striations can fully be removed by a polish-off amount less than required in a conventional way in mirror polishing following surface grinding using an infeed type surface grinder, in which two circular tables, opposite to each other, which are driven and rotate independently from each other, are arranged so that the peripheral end portion of one table coincides with an axial center of a rotary shaft of the other table all time, the two circular tables being located so as to be shifted sideways from each other; not only is a grinding stone held fixedly on an opposite surface of the one table, but the wafer is fixed on an opposite surface of the other table; the two tables are rotated relatively to each other; and at least one table is pressed on the other while at least one table is relatively moved in a direction, so that a surface of the wafer is ground, wherein the surface of the wafer is ground while controlling a
    Type: Grant
    Filed: November 17, 1999
    Date of Patent: March 19, 2002
    Assignee: Shin-Etsu Handotai Co., Ltd.
    Inventors: Tadahiro Kato, Hisashi Oshima, Keiichi Okabe
  • Patent number: 6346485
    Abstract: A method of processing a semiconductor wafer sliced from a monocrystalline ingot comprises at least the steps of chamfering, lapping, etching, mirror-polishing, and cleaning. In the etching step, alkali etching is first performed and then acid etching, preferably reaction-controlled acid etching, is performed. The etching amount of the alkali etching is greater than the etching amount of the acid etching. Alternatively, in the etching step, reaction-controlled acid etching is first performed and then diffusion-controlled acid etching is performed. The etching amount of the reaction-controlled acid etching is greater than the etching amount of the diffusion-controlled acid etching.
    Type: Grant
    Filed: August 7, 2000
    Date of Patent: February 12, 2002
    Assignee: Shin-Etsu Handotai Co., Ltd.
    Inventors: Takashi Nihonmatsu, Seiichi Miyazaki, Masahiko Yoshida, Hideo Kudo, Tadahiro Kato
  • Patent number: 6284658
    Abstract: The present invention has an object to provide a manufacturing process of a semiconductor wafer in which improvement on accuracy in a chamfering portion is realized. The manufacturing process of a semiconductor wafer comprises: a slicing step of obtaining a wafer in the shaped of a thin disk by slicing a single crystal ingot; a surface-grinding step of flattening a surface of the wafer; a chamfering step of chamfering the peripheral edge portions; and mirror-polishing step of mirror-polishing the surface of the wafer, wherein a simultaneous double-side surface-grinding step of grinding both sides of the wafer simultaneously by a double-side grinding machine is existent prior to the chamfering step in order to remove wafer waviness and a secondary grinding step is performed by grinding a single side or simultaneously both sides of the wafer after the chamfering step is carried out, so that improvement on accuracy in a chamfered portion is realized.
    Type: Grant
    Filed: July 7, 1999
    Date of Patent: September 4, 2001
    Assignee: Shin-Etsu Handotai Co., Ltd.
    Inventors: Tadahiro Kato, Sadayuki Okuni, Keiichi Okabe, Hisashi Oshima