Patents by Inventor Toshiya Yokogawa
Toshiya Yokogawa 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: 20240063341Abstract: A light-emitting device includes a light generating portion including an active layer interposed between a first conductivity type layer and a second conductivity type layer. The active layer generates light. The light-emitting device further includes a light guide layer disposed on an optical path of light generated from the active layer. The light guide layer includes a textured structure on the optical path. The light guide layer can have a same conductivity type as the first conductivity type layer.Type: ApplicationFiled: October 30, 2023Publication date: February 22, 2024Inventors: Toshiya YOKOGAWA, Chae Hon KIM, Chung Hoon LEE
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Patent number: 11804573Abstract: A group III-V light-emitting diode is provided. The light-emitting diode includes a light generating portion including an active layer interposed between a first conductivity type semiconductor layer and a second conductivity type semiconductor layer. The active layer generates light. The light-emitting diode further includes an optical trap disposed on an optical path of light generated from the active layer. The optical trap includes a light absorption layer interposed between light guide layers. The light-emitting diode further includes a side reflector disposed on a side surface of the optical trap.Type: GrantFiled: December 11, 2020Date of Patent: October 31, 2023Assignee: Seoul Viosys Co., Ltd.Inventors: Toshiya Yokogawa, Chae Hon Kim, Chung Hoon Lee
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Publication number: 20210119082Abstract: A group III-V light-emitting diode is provided. The light-emitting diode includes a light generating portion including an active layer interposed between a first conductivity type semiconductor layer and a second conductivity type semiconductor layer. The active layer generates light. The light-emitting diode further includes an optical trap disposed on an optical path of light generated from the active layer. The optical trap includes a light absorption layer interposed between light guide layers. The light-emitting diode further includes a side reflector disposed on a side surface of the optical trap.Type: ApplicationFiled: December 11, 2020Publication date: April 22, 2021Applicant: SEOUL VIOSYS CO., LTD.Inventors: Toshiya YOKOGAWA, Chae Hon KIM, Chung Hoon LEE
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Patent number: 9379284Abstract: A nitride semiconductor light emitting chip includes: a conductive substrate including a nitride semiconductor layer; an n-type nitride semiconductor layer, an active layer, and a p-type nitride semiconductor layer sequentially formed on a principal surface of the nitride semiconductor layer; and an n-side electrode formed in contact with the conductive substrate. A recess is formed in a back surface of the conductive substrate opposite to the principal surface. The n-side electrode is in contact with at least part of a surface of the recess. A depth D1 is not less than 25% of a thickness T, where T represents a thickness of the conductive substrate, and D1 represents a depth of the recess.Type: GrantFiled: October 16, 2013Date of Patent: June 28, 2016Assignee: Panasonic Intellectual Property Management Co., Ltd.Inventors: Akira Inoue, Toshiyuki Fujita, Masaki Fujikane, Toshiya Yokogawa
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Patent number: 9324913Abstract: A nitride semiconductor structure includes: a plurality of crystal growth seed regions formed of a nitride semiconductor, of which the principal surface is an m-plane and which extends to a range that defines an angle of not less than 0 degrees and not more than 10 degrees with respect to an a-axis; and a laterally grown region formed of a nitride semiconductor which has extended in a c-axis direction from each of the plurality of crystal growth seed regions. An S width that is the spacing between adjacent ones of the plurality of crystal growth seed regions is at least 20 ?m.Type: GrantFiled: June 2, 2014Date of Patent: April 26, 2016Assignee: Panasonic Intellectual Property Management Co., Ltd.Inventors: Songbaek Choe, Shunji Yoshida, Toshiya Yokogawa
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Patent number: 9318659Abstract: A nitride semiconductor light emitting element includes a light emitting layer. The light emitting layer includes an InxGa1-xN well layer (0<x?1) having a principal surface that is an m-plane. A profile in a depth direction (depth profile) of an In composition ratio x in the InxGa1-xN well layer has a plurality of peaks. Values of the In composition ratios x at the respective plurality of peaks are different from one another.Type: GrantFiled: August 23, 2013Date of Patent: April 19, 2016Assignee: Panasonic Intellectual Property Management Co., Ltd.Inventors: Akira Inoue, Shunji Yoshida, Toshiya Yokogawa
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Patent number: 9287378Abstract: Provided is a nitride semiconductor light-emitting element having a low contact resistance between an n-type nitride semiconductor layer and an n-side electrode. A portion of the n-type nitride semiconductor layer is removed by a plasma etching process using a gas containing halogen to expose a surface region of the n-type nitride semiconductor layer. Next, such an exposed surface region is further subjected to a plasma treatment using a gas containing oxygen. After that, the n-side electrode formed of aluminum is formed so as to be in contact with the surface region. In the surface region, a carrier concentration is decreased from the inside of the n-type nitride semiconductor layer toward the n-side electrode.Type: GrantFiled: July 1, 2014Date of Patent: March 15, 2016Assignee: Panasonic Intellectual Property Management Co., Ltd.Inventors: Mitsuaki Oya, Toshiya Yokogawa
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Patent number: 9276171Abstract: Provided is a nitride semiconductor light-emitting diode having a higher light extraction efficiency and a higher polarization degree. A nitride semiconductor light-emitting diode according to the present invention comprises an active layer generating a polarized light, a first side surface, a second side surface, a third side surface, and a fourth side surface. The first and second side surfaces consist only of a plane including the Z-axis and the Y-axis. The third and fourth side surfaces are perpendicular to the first and second side surfaces and include the X-axis. The third and fourth side surfaces include an inclined surface.Type: GrantFiled: June 2, 2014Date of Patent: March 1, 2016Assignee: PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO., LTD.Inventors: Toshiyuki Fujita, Toshiya Yokogawa, Akira Inoue
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Patent number: 9252330Abstract: A semiconductor light-emitting element according to the present invention includes: an n-type nitride semiconductor layer 21; a p-type nitride semiconductor layer 23; an active layer region 22 which includes an m plane nitride semiconductor layer and which is interposed between the n-type nitride semiconductor layer and the p-type nitride semiconductor layer; an n-type electrode 30 which is electrically connected to the n-type nitride semiconductor layer; a p-type electrode 40 which is electrically connected to the p-type nitride semiconductor layer; a light-emitting face, through which polarized light that has been produced in the active layer region is extracted out of this element; and a striped structure 50 which is provided for the light-emitting face and which has a plurality of projections that run substantially parallel to the a-axis direction of the m plane nitride semiconductor layer.Type: GrantFiled: August 5, 2011Date of Patent: February 2, 2016Assignee: Panasonic Intellectual Property Management Co., Ltd.Inventors: Akihiro Isozaki, Akira Inoue, Atsushi Yamada, Toshiya Yokogawa
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Patent number: 9209254Abstract: In a structure including a gallium nitride-based semiconductor having an m-plane as a principal plane, and a metal layer provided on the principal plane, the principal plane has an n-type conductivity. An interface between the gallium nitride-based semiconductor and the metal layer contains oxygen. The metal layer includes a crystal grain extending form a lower surface to an upper surface of the metal layer.Type: GrantFiled: May 29, 2014Date of Patent: December 8, 2015Assignee: Panasonic Intellectual Property Management Co., Ltd.Inventors: Masaki Fujikane, Akira Inoue, Toshiya Yokogawa
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Patent number: 9209350Abstract: When a belt-like nitride semiconductor stacking structure 110 having a principal plane of an m-plane is broken along a linear groove 104, two or more side surfaces may be formed on the lateral side thereof. This decreases the fabrication efficiency of the triangular prismatic m-plane nitride semiconductor light-emitting diode. To solve this problem, Angle X of not less than 75 degrees and not more than 105 degrees is formed between the linear groove 104 and one cleavage axis selected from the group consisting of an a-axis and a c-axis. Then, the belt-like nitride semiconductor stacking structure 110 was broken along the linear groove 104 to form a quadratic prismatic nitride semiconductor stacking structure 120. Subsequently, the quadratic prismatic nitride semiconductor stacking structure 120 is broken along another linear groove 106 to obtain a triangular prismatic m-plane nitride semiconductor light-emitting diode 130.Type: GrantFiled: September 26, 2014Date of Patent: December 8, 2015Assignee: PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO., LTD.Inventors: Mitsuaki Oya, Toshiya Yokogawa
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Patent number: 9209361Abstract: The present invention improves luminous efficiency of a nitride semiconductor light-emitting element. In the nitride semiconductor light-emitting element, a non-polar or semi-polar Alx2Iny2Gaz2N layer having a thickness of t1 is interposed between the Alx1Iny1Gaz1N layer included in the p-type nitride semiconductor layer and the active layer (0<x2?1, 0?y2<1, 0<z2<1, x2+y2+z2=1). The Alx2Iny2Gaz2N layer has first and second interfaces located close to or in contact with the active layer and the Alx1Iny1Gaz1N layer, respectively. The Alx2Iny2Gaz2N layer has a hydrogen concentration distribution along its thickness direction in the inside thereof in such a manner that the hydrogen concentration is increased from the first interface to a thickness t2 (t2<t1), reaches a peak at the thickness t2, and is decreased from the thickness t2 to the second interface. Magnesium contained in the Alx1Iny1Gaz1N layer is prevented from being diffused into the active layer to improve the luminous efficiency.Type: GrantFiled: June 30, 2014Date of Patent: December 8, 2015Assignee: PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO., LTD.Inventors: Akio Ueta, Masaaki Yuri, Toshiya Yokogawa, Ryou Kato
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Patent number: 9196794Abstract: A semiconductor light-emitting device made of a nitride-based semiconductor includes a semiconductor stacked structure having a nonpolar plane or a semipolar plane as a principal plane, and including an active layer for emitting polarized light. The semiconductor light-emitting device includes a striped structure which is provided in a position intersecting an exit path of the polarized light and includes a plurality of recesses. An angle formed between the extension direction of the recesses and the polarization direction of the polarized light is from 0° to 45°. The recesses have a minute uneven structure (texture) at at least part of a surface of each recess, the minute uneven structure being shallower than the depth of each recess.Type: GrantFiled: April 3, 2014Date of Patent: November 24, 2015Assignee: Panasonic Intellectual Property Management Co., Ltd.Inventors: Toshiyuki Fujita, Akira Inoue, Toshiya Yokogawa
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Publication number: 20150318445Abstract: A nitride-based semiconductor light-emitting device includes: a nitride-based semiconductor multilayer structure including a p-type semiconductor region having an m-plane as a growing plane; and an Ag electrode provided so as to be in contact with the growing plane of the p-type semiconductor region, wherein the Ag electrode has a thickness in a range of not less than 200 nm and not more than 1,000 nm; an integral intensity ratio of an X-ray intensity of a (111) plane on the growing plane of the Ag electrode to that of a (200) plane is in a range of not less than 20 and not more than 100; and the Ag electrode has a reflectance of not less than 70%.Type: ApplicationFiled: July 16, 2015Publication date: November 5, 2015Inventors: Songbaek CHOE, Naomi ANZUE, Ryou KATO, Toshiya YOKOGAWA
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Patent number: 9147804Abstract: A nitride semiconductor light-emitting element includes: n-side and p-side electrodes; n-type and p-type nitride semiconductor layers; and an active layer arranged between the n- and p-type nitride semiconductor layers. The p-type nitride semiconductor layer has a projection having a height of 30 nm to 50 nm. The projection is formed of a p-type nitride semiconductor including magnesium and silicon. The p-type nitride semiconductor has a silicon concentration of 1.0×1017 cm?3 to 6.0×1017 cm?3. The projection projects from the active layer toward the p-side electrode. On a plan view of the nitride semiconductor light-emitting element, the p-side electrode overlaps with the projection. The projection includes a dislocation. The projection is surrounded with a flat surface which is formed of the p-type nitride semiconductor. And the projection has a higher dislocation density than the flat surface.Type: GrantFiled: September 17, 2013Date of Patent: September 29, 2015Assignee: Panasonic Intellectual Property Management Co., Ltd.Inventors: Ryou Kato, Kunimasa Takahashi, Masaki Fujikane, Toshiya Yokogawa
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Patent number: 9130141Abstract: Disclosed is a light-emitting diode element including a first semiconductor layer of a first conductivity type, a second semiconductor layer of a second conductivity type, an active layer. A first electrode is provided on a surface of the second semiconductor layer. A second electrode is provided in a second region of the principal surface of the first semiconductor layer. A conductive layer is arranged such that the conductive layer covers a third region, a fourth region, and a fifth region in the rear surface of the first semiconductor layer. In the rear surface of the first semiconductor layer, the first semiconductor layer includes a sixth region which is not covered with the conductive layer and which overlaps another part of the first electrode. The first semiconductor layer is not provided with a through electrode.Type: GrantFiled: January 2, 2014Date of Patent: September 8, 2015Assignee: Panasonic Intellectual Property Management Co., Ltd.Inventors: Junko Iwanaga, Akira Inoue, Toshiya Yokogawa, Shigeo Hayashi
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Patent number: 9117961Abstract: A nitride-based semiconductor light-emitting element includes a substrate and a nitride semiconductor multilayer structure. The nitride semiconductor multilayer structure includes a nitride semiconductor active layer which emits polarized light. Angle ?, which is formed by at least one of the plurality of lateral surfaces of the substrate with respect to the principal surface of the substrate, is greater than 90°. Angle ?2 (mod 180°), which is an absolute value of an angle which is formed by an intersecting line of at least one of the plurality of lateral surfaces of the substrate and the principal surface of the substrate with respect to a polarization direction in the principal surface of the polarized light, is an angle which does not include 0° or 90°.Type: GrantFiled: February 27, 2013Date of Patent: August 25, 2015Assignee: Panasonic Intellectual Property Management Co., Ltd.Inventors: Akira Inoue, Masaki Fujikane, Toshiya Yokogawa
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Publication number: 20150200330Abstract: When a belt-like nitride semiconductor stacking structure 110 having a principal plane of an m-plane is broken along a linear groove 104, two or more side surfaces may be formed on the lateral side thereof. This decreases the fabrication efficiency of the triangular prismatic m-plane nitride semiconductor light-emitting diode. To solve this problem, Angle X of not less than 75 degrees and not more than 105 degrees is formed between the linear groove 104 and one cleavage axis selected from the group consisting of an a-axis and a c-axis. Then, the belt-like nitride semiconductor stacking structure 110 was broken along the linear groove 104 to form a quadratic prismatic nitride semiconductor stacking structure 120. Subsequently, the quadratic prismatic nitride semiconductor stacking structure 120 is broken along another linear groove 106 to obtain a triangular prismatic m-plane nitride semiconductor light-emitting diode 130.Type: ApplicationFiled: September 26, 2014Publication date: July 16, 2015Inventors: MITSUAKI OYA, TOSHIYA YOKOGAWA
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Publication number: 20150162495Abstract: A nitride semiconductor light-emitting element 300 is a nitride semiconductor light-emitting element which has a multilayer structure 310, the multilayer structure 310 including an active layer which is made of an m-plane nitride semiconductor. The multilayer structure 310 has a light extraction surface 311a which is parallel to an m-plane in the nitride semiconductor active layer 306 and light extraction surfaces 311b which are parallel to a c-plane in the nitride semiconductor active layer 306. The ratio of an area of the light extraction surfaces 311b to an area of the light extraction surface 311a is not more than 46%.Type: ApplicationFiled: December 10, 2014Publication date: June 11, 2015Inventors: Akira INOUE, Toshiya YOKOGAWA, Atsushi YAMADA, Masaki FUJIKANE
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Patent number: 8994031Abstract: In a gallium nitride based compound semiconductor light-emitting element including an active layer, the active layer includes a well layer 104 and a barrier layer 103, each of which is a semiconductor layer of which the growing plane is an m plane. The well layer 104 has a lower surface and an upper surface and has an In composition distribution in which the composition of In changes according to a distance from the lower surface in a thickness direction of the well layer 104. The In composition of the well layer 104 becomes a local minimum at a level that is defined by a certain distance from the lower surface and that portion of the well layer 104 where the In composition becomes the local minimum runs parallel to the lower surface.Type: GrantFiled: January 16, 2013Date of Patent: March 31, 2015Assignee: Panasonic Intellectual Property Management Co., Ltd.Inventors: Ryou Kato, Shunji Yoshida, Toshiya Yokogawa