Patents by Inventor Masaaki TACHIOKA
Masaaki TACHIOKA 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: 20220310548Abstract: An object is to provide highly reliable semiconductor element bonding portion and semiconductor device that have high heat resistance and improved adhesion between a bonding material and a sealing resin. Provided is a semiconductor element bonding portion in which the semiconductor element 11 and an electrically conductive plate 123a are bonded to each other by a bonding layer 10 and the bonding layer 10 includes a metal nanoparticle sintered body 101 and a coupling agent 102 including an SH group.Type: ApplicationFiled: January 28, 2022Publication date: September 29, 2022Applicant: FUJI ELECTRIC CO., LTD.Inventors: Masaaki TACHIOKA, Takashi SAITO
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Patent number: 9972499Abstract: A method of manufacturing a semiconductor device includes providing a semiconductor substrate having a front surface and a back surface; forming a transition metal layer on a surface of the semiconductor substrate; and exposing the semiconductor substrate having the transition metal layer formed thereon to a hydrogen plasma atmosphere formed by microwaves, to cause the transition metal layer to generate heat. During exposure of the semiconductor substrate, a portion of the semiconductor substrate contacting the transition metal layer is heated by a transfer of heat from the transition metal layer and, at an interface of the transition metal layer and the semiconductor substrate, an ohmic contact is formed by reaction of the transition metal layer and the semiconductor substrate, such as to form a transition metal silicide when the semiconductor substrate is silicon carbide. The ohmic contact provides a lower contact resistivity and device properties can be prevented from degrading.Type: GrantFiled: March 9, 2016Date of Patent: May 15, 2018Assignee: FUJI ELECTRIC CO., LTD.Inventors: Haruo Nakazawa, Masaaki Ogino, Tsunehiro Nakajima, Kenichi Iguchi, Masaaki Tachioka, Kiyokazu Nakagawa
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Patent number: 9922858Abstract: Provided is a semiconductor device manufacturing method that includes joining a support substrate to a back side of a semiconductor wafer across a ceramic adhesive layer and a mask, to form a joined body. The method further includes forming a functional structure on a front side of the semiconductor wafer. The method further includes detaching the support substrate from the semiconductor wafer by removing the ceramic adhesive layer and the mask. The method further includes a back side processing step of carrying out back side processing on the back side of the semiconductor wafer.Type: GrantFiled: August 7, 2015Date of Patent: March 20, 2018Assignee: FUJI ELECTRIC CO., LTD.Inventors: Masaaki Tachioka, Tsunehiro Nakajima
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Patent number: 9892919Abstract: A first nickel film is deposited inside a contact hole of an interlayer dielectric formed on an n+-type SiC substrate. Irradiation with a first laser is carried out, forming an Ohmic contact with a silicon carbide semiconductor. A second nickel film and a front surface electrode film are deposited on the first nickel film, forming a source electrode. The back surface of the n+-type SiC substrate is ground, and a third nickel film is formed on the ground back surface of the n+-type SiC substrate. Irradiation with a second laser is carried out, forming an Ohmic contact with the silicon carbide semiconductor. A fourth nickel film and a back surface electrode film are deposited on the third nickel film, forming a drain electrode. By so doing, it is possible to prevent electrical characteristic deterioration of a semiconductor device, and to prevent warping and cracking of a wafer.Type: GrantFiled: April 9, 2015Date of Patent: February 13, 2018Assignee: FUJI ELECTRIC CO., LTD.Inventors: Haruo Nakazawa, Masaaki Tachioka, Naoto Fujishima, Masaaki Ogino, Tsunehiro Nakajima, Kenichi Iguchi
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Patent number: 9728441Abstract: A method for manufacturing a semiconductor device includes: bonding at least a part of the rear surface of a semiconductor wafer, and a supporting substrate in use of using a silane coupling agent; forming a functional structure on a front surface of the semiconductor wafer; placing a condensation point of laser light transmitted through the semiconductor wafer on a bonding interface between the semiconductor wafer and the supporting substrate, and irradiating the bonding interface with the laser light, thereby forming a fracture layer on at least a part of an outer circumferential section of the bonding interface; separating the bonding interface; and carrying out rear surface processing on the rear surface of the semiconductor wafer.Type: GrantFiled: September 3, 2015Date of Patent: August 8, 2017Assignee: FUJI ELECTRIC CO., LTD.Inventors: Masaaki Tachioka, Tsunehiro Nakajima
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Patent number: 9564334Abstract: A method of manufacturing a semiconductor device includes forming a device structure in a surface of a semiconductor substrate, forming, in a face of the semiconductor substrate, a transition metal layer that contacts the semiconductor substrate, and exposing the semiconductor substrate having the transition metal layer formed thereon to a hydrogen plasma atmosphere formed by microwaves to cause the transition metal layer to generate heat. During exposure of the semiconductor substrate to the hydrogen plasma atmosphere, a portion of the semiconductor substrate contacting the transition metal layer is heated by a transfer of the heat from the transition metal layer, and an ohmic contact is formed at an interface of the transition metal layer and the semiconductor substrate by reaction of the transition metal layer and the semiconductor substrate. When the semiconductor substrate is silicon carbide, the ohmic contact is composed of a silicide, such as a transition metal silicide.Type: GrantFiled: March 9, 2016Date of Patent: February 7, 2017Assignee: FUJI ELECTRIC CO., LTD.Inventors: Kenichi Iguchi, Haruo Nakazawa, Tsunehiro Nakajima, Masaaki Ogino, Masaaki Tachioka
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Patent number: 9548205Abstract: A method of manufacturing a semiconductor device that reduces degradation of device properties includes forming an impurity region in a surface layer of a semiconductor substrate by ion injection; forming a transition metal layer in a surface of the impurity region; and exposing the semiconductor substrate with the transition metal layer formed thereon to a hydrogen plasma atmosphere formed by microwaves. The transition metal layer is heated and the heat is transferred from the transition metal layer to the impurity region to form an ohmic contact at the interface of the transition metal layer and the impurity region by reaction of the transition metal layer and the impurity region, and the impurity region is activated. When the substrate is a silicon carbide substrate, the ohmic contact is composed of a transition metal silicide and the impurity region, which is an ion injection layer, is activated.Type: GrantFiled: March 9, 2016Date of Patent: January 17, 2017Assignee: FUJI ELECTRIC CO., LTD.Inventors: Haruo Nakazawa, Masaaki Ogino, Tsunehiro Nakajima, Kenichi Iguchi, Masaaki Tachioka
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Publication number: 20160189968Abstract: A method of manufacturing a semiconductor device that reduces degradation of device properties includes forming an impurity region in a surface layer of a semiconductor substrate by ion injection; forming a transition metal layer in a surface of the impurity region; and exposing the semiconductor substrate with the transition metal layer formed thereon to a hydrogen plasma atmosphere formed by microwaves. The transition metal layer is heated and the heat is transferred from the transition metal layer to the impurity region to form an ohmic contact at the interface of the transition metal layer and the impurity region by reaction of the transition metal layer and the impurity region, and the impurity region is activated. When the substrate is a silicon carbide substrate, the ohmic contact is composed of a transition metal silicide and the impurity region, which is an ion injection layer, is activated.Type: ApplicationFiled: March 9, 2016Publication date: June 30, 2016Applicant: FUJI ELECTRIC CO., LTD.Inventors: Haruo NAKAZAWA, Masaaki OGINO, Tsunehiro NAKAJIMA, Kenichi IGUCHI, Masaaki TACHIOKA
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Publication number: 20160189967Abstract: A method of manufacturing a semiconductor device includes providing a semiconductor substrate having a front surface and a back surface; forming a transition metal layer in a surface of the semiconductor substrate; and exposing the semiconductor substrate having the transition metal layer formed thereon to a hydrogen plasma atmosphere formed by microwaves, to cause the transition metal layer to generate heat, Thus, during the exposure of the semiconductor substrate, a portion of the semiconductor substrate contacting the transition metal layer is heated by a transfer of heat from the transition metal layer and, at an interface of the transition metal layer and the semiconductor substrate, an ohmic contact is formed by reaction of the transition metal layer and the semiconductor substrate, such as to form a transition metal silicide when the semiconductor substrate is silicon carbide. The ohmic contact provides a lower contact resistivity and device properties can be prevented from degrading.Type: ApplicationFiled: March 9, 2016Publication date: June 30, 2016Applicant: FUJI ELECTRIC CO., LTD.Inventors: Haruo NAKAZAWA, Masaaki OGINO, Tsunehiro NAKAJIMA, Kenichi IGUCHI, Masaaki TACHIOKA, Kiyokazu NAKAGAWA
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Publication number: 20160189969Abstract: A method of manufacturing a semiconductor device includes forming a device structure in a surface of a semiconductor substrate, forming, in a face of the semiconductor substrate, a transition metal layer that contacts the semiconductor substrate, and exposing the semiconductor substrate having the transition metal layer formed thereon to a hydrogen plasma atmosphere formed by microwaves to cause the transition metal layer to generate heat. During exposure of the semiconductor substrate to the hydrogen plasma atmosphere, a portion of the semiconductor substrate contacting the transition metal layer is heated by a transfer of the heat from the transition metal layer, and an ohmic contact is formed at an interface of the transition metal layer and the semiconductor substrate by reaction of the transition metal layer and the semiconductor substrate. When the semiconductor substrate is silicon carbide, the ohmic contact is composed of a silicide, such as a transition metal silicide.Type: ApplicationFiled: March 9, 2016Publication date: June 30, 2016Applicant: FUJI ELECTRIC CO., LTD.Inventors: Kenichi IGUCHI, Haruo NAKAZAWA, Tsunehiro NAKAJIMA, Masaaki OGINO, Masaaki TACHIOKA
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Publication number: 20150380292Abstract: A method for manufacturing a semiconductor device includes: bonding at least a part of the rear surface of a semiconductor wafer, and a supporting substrate in use of using a silane coupling agent; forming a functional structure on a front surface of the semiconductor wafer; placing a condensation point of laser light transmitted through the semiconductor wafer on a bonding interface between the semiconductor wafer and the supporting substrate, and irradiating the bonding interface with the laser light, thereby forming a fracture layer on at least a part of an outer circumferential section of the bonding interface; separating the bonding interface; and carrying out rear surface processing on the rear surface of the semiconductor wafer.Type: ApplicationFiled: September 3, 2015Publication date: December 31, 2015Applicant: FUJI ELECTRIC CO., LTD.Inventors: Masaaki TACHIOKA, Tsunehiro NAKAJIMA
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Publication number: 20150348818Abstract: Provided is a semiconductor device manufacturing method that includes joining a support substrate to a back side of a semiconductor wafer across a ceramic adhesive layer and a mask, to form a joined body. The method further includes forming a functional structure on a front side of the semiconductor wafer. The method further includes detaching the support substrate from the semiconductor wafer by removing the ceramic adhesive layer and the mask. The method further includes a back side processing step of carrying out back side processing on the back side of the semiconductor wafer.Type: ApplicationFiled: August 7, 2015Publication date: December 3, 2015Applicant: FUJI ELECTRIC CO., LTD.Inventors: Masaaki TACHIOKA, Tsunehiro NAKAJIMA
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Publication number: 20150214053Abstract: A first nickel film is deposited inside a contact hole of an interlayer dielectric formed on an n+-type SiC substrate. Irradiation with a first laser is carried out, forming an Ohmic contact with a silicon carbide semiconductor. A second nickel film and a front surface electrode film are deposited on the first nickel film, forming a source electrode. The back surface of the n+-type SiC substrate is ground, and a third nickel film is formed on the ground back surface of the n+-type SiC substrate. Irradiation with a second laser is carried out, forming an Ohmic contact with the silicon carbide semiconductor. A fourth nickel film and a back surface electrode film are deposited on the third nickel film, forming a drain electrode. By so doing, it is possible to prevent electrical characteristic deterioration of a semiconductor device, and to prevent warping and cracking of a wafer.Type: ApplicationFiled: April 9, 2015Publication date: July 30, 2015Applicant: FUJI ELECTRIC CO., LTD.Inventors: Haruo NAKAZAWA, Masaaki TACHIOKA, Naoto FUJISHIMA, Masaaki OGINO, Tsunehiro NAKAJIMA, Kenichi IGUCHI