Patents by Inventor Motoaki Iwaya
Motoaki Iwaya 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: 20240113174Abstract: A laminate includes an amorphous glass substrate, and an AlN layer formed on the amorphous glass substrate. The AlN layer is c-axis oriented on the amorphous glass substrate, a glass transition temperature (Tg) of the amorphous glass substrate is 720° C. to 810° C., a coefficient of thermal expansion (CTE) of the amorphous glass substrate is 3.5×10?6 [1/K] to 4.0×10?6 [1/K], and a softening point of the amorphous glass substrate is 950° C. to 1050° C.Type: ApplicationFiled: December 7, 2023Publication date: April 4, 2024Applicants: Japan Display Inc., MEIJO UNIVERSITYInventors: Masanobu IKEDA, Arichika ISHIDA, Satoshi KAMIYAMA, Motoaki IWAYA, Tetsuya TAKEUCHI
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Publication number: 20240072101Abstract: An LED array includes: a substrate having a depressing-projecting structure formed on a surface of the substrate; a planarization layer formed on the depressing-projecting structure; a plurality of micro LED elements each of which is formed on the planarization layer; and a stray light attenuating groove formed between a pair of adjacent micro LED elements among the plurality of micro LED elements, and extending from toward the pair of micro LED elements to toward the depressing-projecting structure at least part way of the planarization layer.Type: ApplicationFiled: August 5, 2023Publication date: February 29, 2024Applicants: SHARP KABUSHIKI KAISHA, Meijo UniversityInventors: YOSHIHIRO UETA, Motoaki IWAYA, Yoshinobu SUEHIRO, Yuta IMAIZUMI, Tatsunari SAITO
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Patent number: 11462659Abstract: Provided is a semiconductor light emitting device including a growth substrate; a pillar-shaped semiconductor layer formed on the growth substrate; and a buried semiconductor layer formed to cover the pillar-shaped semiconductor layer, wherein the pillar-shaped semiconductor layer has an n-type nanowire layer formed at a center, an active layer formed on an outermore side than the n-type nanowire layer, a p-type semiconductor layer formed on an outermore side than the active layer and a tunnel junction layer formed on an outermore side than the p-type semiconductor layer, and wherein at least a part of the pillar-shaped semiconductor layer is provided with a removed region formed by removing from the buried semiconductor layer to a part of the tunnel junction layer.Type: GrantFiled: September 9, 2020Date of Patent: October 4, 2022Assignees: KOITO MANUFACTURING CO., LTD., MEIJO UNIVERSITY, TOYODA GOSEI CO., LTD.Inventors: Satoshi Kamiyama, Tetsuya Takeuchi, Motoaki Iwaya, Isamu Akasaki, Lu Weifang, Naoki Sone, Kazuyoshi Iida, Ryo Nakamura, Masaki Oya
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Publication number: 20220285580Abstract: The semiconductor light-emitting device includes an n-type semiconductor layer, a plurality of columnar semiconductors on the n-type semiconductor layer, a buried layer filling in a space between the columnar semiconductors, and a current suppression region suppressing a current. The columnar semiconductors has a hexagonal column and an active layer covering the hexagonal column. The hexagonal column has a hexagonal first surface and a second surface opposite to the first surface. The first surface of the columnar semiconductors faces the base layer. The second surface of the columnar semiconductors faces the current suppression region.Type: ApplicationFiled: February 16, 2022Publication date: September 8, 2022Inventors: Koji Okuno, Koichi MUZUTANI, Masaki OYA, Kazuyoshi IIDA, Satoshi KAMIYAMA, Tetsuya TEKEUCHI, Motoaki IWAYA, Isamu AKASAKI
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Publication number: 20220246793Abstract: To suppress current leakage between the semiconductor layer below the mask and the buried layer above the mask. To reduce the drive voltage and improve the emission efficiency by improving the efficiency of carrier injection into the active layer. The semiconductor light-emitting device includes a substrate, a mask, a columnar semiconductor, a buried layer, a cathode electrode, and an anode electrode. The substrate has a conductive substrate, an n-type semiconductor layer disposed on the conductive substrate, and a p-type semiconductor layer disposed on the n-type semiconductor layer. The p-type semiconductor layer has a high resistance, thereby enhancing insulation between the n-type semiconductor layer and the buried layer.Type: ApplicationFiled: January 21, 2022Publication date: August 4, 2022Inventors: Koji OKUNO, Koichi MIZUTANI, Masaki OYA, Kazuyoshi IIDA, Satoshi KAMIYAMA, Tetsuya TAKEUCHI, Motoaki IWAYA, Isamu AKASAKI
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Publication number: 20220246789Abstract: A buried layer forming step includes three steps of a facet structure forming step, a c-plane forming step, and a flattening step. In the facet structure forming step, a buried layer grows to form a periodic facet structure that matches an arrangement pattern of columnar semiconductors. In the c-plane forming step, the buried layer grows such that a {0001} plane (upper surface) is formed in a region of the buried layer corresponding to an upper portion of the columnar semiconductor. In the flattening step, lateral growth of the buried layer is promoted and the c-plane formed in the c-plane forming step is widened to flatten a surface of the buried layer.Type: ApplicationFiled: January 28, 2022Publication date: August 4, 2022Inventors: Koji OKUNO, Koichi MIZUTANI, Masaki OYA, Kazuyoshi IIDA, Naoki SONE, Satoshi KAMIYAMA, Tetsuya TAKEUCHI, Motoaki IWAYA, Isamu AKASAKI
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Publication number: 20210375614Abstract: Provided is a nitride semiconductor element capable of stably withstand being driven at high current density without becoming insulated. The nitride semiconductor element includes an active layer and an AlGaN layer formed above the active layer and formed of AlGaN, the AlGaN containing Mg and having an Al composition ratio decreasing in a direction away from the active layer, and the Al composition ratio being larger than 0.2, in which the AlGaN layer includes a first AlGaN region in which a compositional gradient a1 of the Al composition ratio is larger than 0 Al %/nm and smaller than 0.22 Al %/nm, and a concentration b1 of the Mg in the AlGaN layer is larger than 0 cm?3 and smaller than 7.0×1019×a1-2.0×1018 cm?3.Type: ApplicationFiled: March 18, 2021Publication date: December 2, 2021Applicant: ASAHI KASEI KABUSHIKI KAISHAInventors: Kosuke SATO, Motoaki IWAYA
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Publication number: 20210366703Abstract: Provided is a nitride semiconductor element that does not cause element breakdown even when driven at high current density. A nitride semiconductor element includes an active layer, an electron block layer formed above the active layer, an AlGaN layer formed on the electron block layer, and a cover layer covering an upper surface of the AlGaN layer and formed of AlGaN or GaN having a lower Al composition ratio than in the AlGaN layer, in which the AlGaN layer includes protrusions provided on a surface opposite to the active layer, and the cover layer covers the protrusions. The AlGaN layer is preferably formed of AlGaN having an Al composition ratio decreasing in a direction away from the active layer, and the protrusions preferably have a frustum shape.Type: ApplicationFiled: March 18, 2021Publication date: November 25, 2021Applicant: ASAHI KASEI KABUSHIKI KAISHAInventors: Kosuke SATO, Motoaki IWAYA
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Publication number: 20210313760Abstract: To provide a Fabry-Perot semiconductor laser diode obtained through a step of forming a mirror facet using an etching technology, in which the threshold current density for laser oscillation is reduced. A method for manufacturing a semiconductor laser diode includes a step of forming a plurality of semiconductor laser diodes on a substrate, and then dividing the substrate into each semiconductor laser diode.Type: ApplicationFiled: March 18, 2021Publication date: October 7, 2021Applicant: ASAHI KASEI KABUSHIKI KAISHAInventors: Kosuke SATO, Motoaki IWAYA
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Patent number: 11088512Abstract: This invention aims at providing a nitride semiconductor causing no element breakdown even in driving under a high current density. A nitride semiconductor element is provided with a nitride semiconductor active layer made of AlxGa(1-x)N and a composition change layer made above the nitride semiconductor active layer and made of Alx3Ga(1-x3)N in which an Al composition ratio x3 decreases in a direction away from the nitride semiconductor active layer.Type: GrantFiled: March 3, 2020Date of Patent: August 10, 2021Assignee: Asahi Kasei Kabushiki KaishaInventors: Kosuke Sato, Motoaki Iwaya, Shinji Yasue, Yuya Ogino
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Publication number: 20210074877Abstract: Provided is a semiconductor light emitting device including a growth substrate; a pillar-shaped semiconductor layer formed on the growth substrate; and a buried semiconductor layer formed to cover the pillar-shaped semiconductor layer, wherein the pillar-shaped semiconductor layer has an n-type nanowire layer formed at a center, an active layer formed on an outermore side than the n-type nanowire layer, a p-type semiconductor layer formed on an outermore side than the active layer and a tunnel junction layer formed on an outermore side than the p-type semiconductor layer, and wherein at least a part of the pillar-shaped semiconductor layer is provided with a removed region formed by removing from the buried semiconductor layer to a part of the tunnel junction layer.Type: ApplicationFiled: September 9, 2020Publication date: March 11, 2021Applicants: KOITO MANUFACTURING CO., LTD., MEIJO UNIVERSITY, TOYODA GOSEI CO., LTD.Inventors: Satoshi Kamiyama, Tetsuya Takeuchi, Motoaki Iwaya, Isamu Akasaki, Lu Weifang, Naoki Sone, Kazuyoshi Iida, Ryo Nakamura, Masaki Oya
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Patent number: 10833223Abstract: To provide a Group III nitride semiconductor light-emitting device exhibiting the improved light extraction efficiency as well as reducing the influence of polarization that a p-type conductivity portion and an n-type conductivity portion occur in the AlGaN layer caused by the Al composition variation, and a production method therefor. A first p-type contact layer is a p-type AlGaN layer. A second p-type contact layer is a p-type AlGaN layer. The Al composition in the first p-type contact layer is reduced with distance from a light-emitting layer. The Al composition in the second p-type contact layer is reduced with distance from the light-emitting layer. The Al composition in the second p-type contact layer is lower than that in the first p-type contact layer. The Al composition variation rate to the unit thickness in the second p-type contact layer is higher than that in the first p-type contact layer.Type: GrantFiled: November 8, 2018Date of Patent: November 10, 2020Assignees: TOYODA GOSEI CO., LTD., MEIJO UNIVERSITYInventors: Tetsuya Takeuchi, Satoshi Kamiyama, Motoaki Iwaya, Isamu Akasaki, Hisanori Kojima, Toshiki Yasuda, Kazuyoshi Iida
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Publication number: 20200287354Abstract: This invention aims at providing a nitride semiconductor causing no element breakdown even in driving under a high current density. A nitride semiconductor element is provided with a nitride semiconductor active layer made of AlxGa(1-x)N and a composition change layer made above the nitride semiconductor active layer and made of Alx3Ga(1-x3)N in which an Al composition ratio x3 decreases in a direction away from the nitride semiconductor active layer.Type: ApplicationFiled: March 3, 2020Publication date: September 10, 2020Applicant: ASAHI KASEI KABUSHIKI KAISHAInventors: Kosuke SATO, Motoaki IWAYA, Shinji YASUE, Yuya OGINO
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Patent number: 10734225Abstract: A nitride semiconductor substrate includes a sapphire substrate and a nitride semiconductor layer formed thereon and containing a group III element including Al and nitrogen as a main component. A surface of the sapphire substrate where the nitride semiconductor layer is formed includes recesses having a maximum opening size of from 2 nm to 60 nm in an amount of from 1×109 pieces to 1×1011 pieces per cm2. The recesses and surfaces immediately above the recesses form spaces. Of a surface of the nitride semiconductor layer on the sapphire substrate side, a height difference ?H between a surface immediately above of each recess and a surface in contact with a flat surface is 10 nm or less. A portion of the nitride semiconductor layer above each recess has a crystalline structure produced by growth along a polar plane of the group III element.Type: GrantFiled: November 8, 2017Date of Patent: August 4, 2020Assignee: ASAHI KASEI KABUSHIKI KAISHAInventors: Akira Yoshikawa, Tomohiro Morishita, Motoaki Iwaya
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Publication number: 20200144451Abstract: Fabricating a high-quality nitride semiconductor crystal at a lower temperature. A nitride semiconductor crystal is fabricated by supplying onto a substrate (105) a group III element and/or a compound thereof, a nitrogen element and/or a compound thereof and an Sb element and/or a compound thereof, all of which serve as materials, and thereby vapor-growing at least one layer of nitride semiconductor film (104). A supply ratio of the Sb element to the nitrogen element in a growth process of the at least one layer of the nitride semiconductor film (104) is set to not less than 0.004.Type: ApplicationFiled: January 9, 2020Publication date: May 7, 2020Applicant: MEIJO UNIVERSITYInventors: Tetsuya TAKEUCHI, Tomoyuki SUZUKI, Hiroki SASAJIMA, Motoaki IWAYA, Isamu AKASAKI
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Patent number: 10593831Abstract: Achieving resistance reduction of a nitride semiconductor multilayer film reflector. In the nitride semiconductor multilayer film reflector, a first semiconductor layer has a higher Al composition than a second semiconductor layer. A first composition-graded layer is interposed between the first and second semiconductor layers so as to be located at a group III element face side of the first semiconductor layer, the first composition-graded layer being adjusted so that its Al composition becomes lower as coming close to the second semiconductor layer. A second composition-graded layer is interposed between the first and second semiconductor layers so as to be located at a nitride face side of the first semiconductor layer. The second composition-graded layer is adjusted so that its Al composition becomes lower as coming close to the second semiconductor layer.Type: GrantFiled: March 19, 2014Date of Patent: March 17, 2020Assignee: MEIJO UNIVERSITYInventors: Tetsuya Takeuchi, Motoaki Iwaya, Isamu Akasaki
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Publication number: 20190355571Abstract: A nitride semiconductor substrate includes a sapphire substrate and a nitride semiconductor layer formed thereon and containing a group III element including Al and nitrogen as a main component. A surface of the sapphire substrate where the nitride semiconductor layer is formed includes recesses having a maximum opening size of from 2 nm to 60 nm in an amount of from 1×109 pieces to 1×1011 pieces per cm2. The recesses and surfaces immediately above the recesses form spaces. Of a surface of the nitride semiconductor layer on the sapphire substrate side, a height difference ?H between a surface immediately above of each recess and a surface in contact with a flat surface is 10 nm or less. A portion of the nitride semiconductor layer above each recess has a crystalline structure produced by growth along a polar plane of the group III element.Type: ApplicationFiled: November 8, 2017Publication date: November 21, 2019Applicants: ASAHI KASEI KABUSHIKI KAISHA, MEIJO UNIVERSITYInventors: Akira Yoshikawa, Tomohiro Morishita, Motoaki Iwaya
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Patent number: 10424684Abstract: An MSM ultraviolet ray receiving element has a low dark state current value and a good photosensitivity. The MSM ultraviolet ray receiving element has a first nitride semiconductor layer on a substrate, a second nitride semiconductor layer on the first nitride semiconductor layer, and first and second electrodes on the second nitride semiconductor layer. The first nitride semiconductor layer contains AlXGa(1-X)N (0.4?X?0.90). The second nitride semiconductor layer contains AlYGa(1-Y)N with a film thickness t (nm) satisfying 5?t?25. The first electrode and the second electrode contain a material containing at least three elements of Ti, Al, Au, Ni, V, Mo, Hf, Ta, W, Nb, Zn, Ag, Cr, and Zr. Al composition ratios X and Y and a film thickness t satisfy ?0.009×t+X+0.22?0.03?Y??0.009×t+X+0.22+0.03.Type: GrantFiled: June 8, 2018Date of Patent: September 24, 2019Assignee: ASAHI KASEI KABUSHIKI KAISHAInventors: Akira Yoshikawa, Kazuhiro Nagase, Motoaki Iwaya, Saki Ushida
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Publication number: 20190148592Abstract: To provide a Group III nitride semiconductor light-emitting device exhibiting the improved light extraction efficiency as well as reducing the influence of polarization that a p-type conductivity portion and an n-type conductivity portion occur in the AlGaN layer caused by the Al composition variation, and a production method therefor. A first p-type contact layer is a p-type AlGaN layer. A second p-type contact layer is a p-type AlGaN layer. The Al composition in the first p-type contact layer is reduced with distance from a light-emitting layer. The Al composition in the second p-type contact layer is reduced with distance from the light-emitting layer. The Al composition in the second p-type contact layer is lower than that in the first p-type contact layer. The Al composition variation rate to the unit thickness in the second p-type contact layer is higher than that in the first p-type contact layer.Type: ApplicationFiled: November 8, 2018Publication date: May 16, 2019Inventors: Tetsuya TAKEUCHI, Satoshi KAMIYAMA, Motoaki IWAYA, Isamu AKASAKI, Hisanori KOJIMA, Toshiki YASUDA, Kazuyoshi IIDA
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Publication number: 20180358500Abstract: An MSM ultraviolet ray receiving element has a low dark state current value and a good photosensitivity. The MSM ultraviolet ray receiving element has a first nitride semiconductor layer on a substrate, a second nitride semiconductor layer on the first nitride semiconductor layer, and first and second electrodes on the second nitride semiconductor layer. The first nitride semiconductor layer contains AlXGa(1-X)N (0.4?X?0.90). The second nitride semiconductor layer contains AlYGa(1-Y)N with a film thickness t (nm) satisfying 5?t?25. The first electrode and the second electrode contain a material containing at least three elements of Ti, Al, Au, Ni, V, Mo, Hf, Ta, W, Nb, Zn, Ag, Cr, and Zr. Al composition ratios X and Y and a film thickness t satisfy ?0.009×t+X+0.22?0.03?Y??0.009×t+X+0.22+0.03.Type: ApplicationFiled: June 8, 2018Publication date: December 13, 2018Applicant: ASAHI KASEI KABUSHIKI KAISHAInventors: Akira YOSHIKAWA, Kazuhiro NAGASE, Motoaki IWAYA, Saki USHIDA