Patents by Inventor Kenichi Hirotsu
Kenichi Hirotsu 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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Patent number: 7750377Abstract: A vertical JFET 1a according to the present invention has an n+ type drain semiconductor portion 2, an n-type drift semiconductor portion 3, a p+ type gate semiconductor portion 4, an n-type channel semiconductor portion 5, an n+ type source semiconductor portion 7, and a p+ type gate semiconductor portion 8. The n-type drift semiconductor portion 3 is placed on a principal surface of the n+ type drain semiconductor portion 2 and has first to fourth regions 3a to 3d extending in a direction intersecting with the principal surface. The p+ type gate semiconductor portion 4 is placed on the first to third regions 3a to 3c of the n-type drift semiconductor portion 3. The n-type channel semiconductor portion 5 is placed along the p+ type gate semiconductor portion 4 and is electrically connected to the fourth region 3d of the n-type drift semiconductor portion 3.Type: GrantFiled: June 28, 2007Date of Patent: July 6, 2010Assignee: Sumitomo Electric Industries, Ltd.Inventors: Takashi Hoshino, Shin Harada, Kazuhiro Fujikawa, Satoshi Hatsukawa, Kenichi Hirotsu
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Patent number: 7671387Abstract: A lateral junction field effect transistor includes a first gate electrode layer arranged in a third semiconductor layer between source/drain region layers, having a lower surface extending on the second semiconductor layer, and doped with p-type impurities more heavily than the second semiconductor layer, and a second gate electrode layer arranged in a fifth semiconductor layer between the source/drain region layers, having a lower surface extending on a fourth semiconductor layer, having substantially the same concentration of p-type impurities as the first gate electrode layer, and having the same potential as the first gate electrode layer. Thereby, the lateral junction field effect transistor has a structure, which can reduce an on-resistance while maintaining good breakdown voltage properties.Type: GrantFiled: July 24, 2008Date of Patent: March 2, 2010Assignee: Sumitomo Electric Industries, Ltd.Inventors: Kazuhiro Fujikawa, Shin Harada, Kenichi Hirotsu, Satoshi Hatsukawa, Takashi Hoshino, Hiroyuki Matsunami, Tsunenobu Kimoto
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Patent number: 7671388Abstract: A lateral junction field effect transistor includes a first gate electrode layer arranged in a third semiconductor layer between source/drain region layers, having a lower surface extending on the second semiconductor layer, and doped with p-type impurities more heavily than the second semiconductor layer, and a second gate electrode layer arranged in a fifth semiconductor layer between the source/drain region layers, having a lower surface extending on a fourth semiconductor layer, having substantially the same concentration of p-type impurities as the first gate electrode layer, and having the same potential as the first gate electrode layer. Thereby, the lateral junction field effect transistor has a structure, which can reduce an on-resistance while maintaining good breakdown voltage properties.Type: GrantFiled: September 1, 2009Date of Patent: March 2, 2010Assignee: Sumitomo Electric Industries, Ltd.Inventors: Kazuhiro Fujikawa, Shin Harada, Kenichi Hirotsu, Satoshi Hatsukawa, Takashi Hoshino, Hiroyuki Matsunami, Tsunenobu Kimoto
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Publication number: 20090315082Abstract: A lateral junction field effect transistor includes a first gate electrode layer arranged in a third semiconductor layer between source/drain region layers, having a lower surface extending on the second semiconductor layer, and doped with p-type impurities more heavily than the second semiconductor layer, and a second gate electrode layer arranged in a fifth semiconductor layer between the source/drain region layers, having a lower surface extending on a fourth semiconductor layer, having substantially the same concentration of p-type impurities as the first gate electrode layer, and having the same potential as the first gate electrode layer. Thereby, the lateral junction field effect transistor has a structure, which can reduce an on-resistance while maintaining good breakdown voltage properties.Type: ApplicationFiled: September 1, 2009Publication date: December 24, 2009Applicant: Sumitomo Electric Industries, Ltd.Inventors: Kazuhiro Fujikawa, Shin Harada, Kenichi Hirotsu, Satoshi Hatsukawa, Takashi Hoshino, Hiroyuki Matsunami, Tsunenobu Kimoto
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Patent number: 7528426Abstract: A lateral JFET has a basic structure including an n-type semiconductor layer (3) formed of an n-type impurity region and a p-type semiconductor layer formed of a p-type impurity region on the n-type semiconductor layer (3). Moreover, in the p-type semiconductor layer, there are provided a p+-type gate region layer (7) extending into the n-type semiconductor layer (3) and containing p-type impurities of an impurity concentration higher than that of the n-type semiconductor layer (3) and an n+-type drain region layer (9) spaced from the p+-type gate region layer (7) by a predetermined distance and containing n-type impurities of an impurity concentration higher than that of the n-type semiconductor layer (3). With this structure, the lateral JFET can be provided that has an ON resistance further decreased while maintaining a high breakdown voltage performance.Type: GrantFiled: January 20, 2006Date of Patent: May 5, 2009Assignee: Sumitomo Electric Industries, Ltd.Inventors: Shin Harada, Kenichi Hirotsu, Hiroyuki Matsunami, Tsunenobu Kimoto
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Publication number: 20080277696Abstract: A lateral junction field effect transistor includes a first gate electrode layer arranged in a third semiconductor layer between source/drain region layers, having a lower surface extending on the second semiconductor layer, and doped with p-type impurities more heavily than the second semiconductor layer, and a second gate electrode layer arranged in a fifth semiconductor layer between the source/drain region layers, having a lower surface extending on a fourth semiconductor layer, having substantially the same concentration of p-type impurities as the first gate electrode layer, and having the same potential as the first gate electrode layer. Thereby, the lateral junction field effect transistor has a structure, which can reduce an on-resistance while maintaining good breakdown voltage properties.Type: ApplicationFiled: July 24, 2008Publication date: November 13, 2008Applicant: Sumitomo Electric Industries, Ltd.Inventors: Kazuhiro Fujikawa, Shin Harada, Kenichi Hirotsu, Satoshi Hatsukawa, Takashi Hoshino, Hiroyuki Matsunami, Tsunenobu Kimoto
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Patent number: 7420232Abstract: A lateral junction field effect transistor includes a first gate electrode layer arranged in a third semiconductor layer between source/drain region layers, having a lower surface extending on the second semiconductor layer, and doped with p-type impurities more heavily than the second semiconductor layer, and a second gate electrode layer arranged in a fifth semiconductor layer between the source/drain region layers, having a lower surface extending on a fourth semiconductor layer, having substantially the same concentration of p-type impurities as the first gate electrode layer, and having the same potential as the first gate electrode layer. Thereby, the lateral junction field effect transistor has a structure, which can reduce an on-resistance while maintaining good breakdown voltage properties.Type: GrantFiled: April 11, 2006Date of Patent: September 2, 2008Assignee: Sumitomo Electric Industries, Ltd.Inventors: Kazuhiro Fujikawa, Shin Harada, Kenichi Hirotsu, Satoshi Hatsukawa, Takashi Hoshino, Hiroyuki Matsunami, Tsunenobu Kimoto
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Publication number: 20070278540Abstract: A vertical JFET 1a according to the present invention has an n+ type drain semiconductor portion 2, an n-type drift semiconductor portion 3, a p+ type gate semiconductor portion 4, an n-type channel semiconductor portion 5, an n+ type source semiconductor portion 7, and a p+ type gate semiconductor portion 8. The n-type drift semiconductor portion 3 is placed on a principal surface of the n+ type drain semiconductor portion 2 and has first to fourth regions 3a to 3d extending in a direction intersecting with the principal surface. The p+ type gate semiconductor portion 4 is placed on the first to third regions 3a to 3c of the n-type drift semiconductor portion 3. The n-type channel semiconductor portion 5 is placed along the p+ type gate semiconductor portion 4 and is electrically connected to the fourth region 3d of the n-type drift semiconductor portion 3.Type: ApplicationFiled: June 28, 2007Publication date: December 6, 2007Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.Inventors: Takashi Hoshino, Shin Harada, Kazuhiro Fujikawa, Satoshi Hatsukawa, Kenichi Hirotsu
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Patent number: 7282760Abstract: A vertical JFET 1a according to the present invention has an n+ type drain semiconductor portion 2, an n-type drift semiconductor portion 3, a p+ type gate semiconductor portion 4, an n-type channel semiconductor portion 5, an n+ type source semiconductor portion 7, and a p+ type gate semiconductor portion 8. The n-type drift semiconductor portion 3 is placed on a principal surface of the n+ type drain semiconductor portion 2 and has first to fourth regions 3a to 3d extending in a direction intersecting with the principal surface. The p+ type gate semiconductor portion 4 is placed on the first to third regions 3a to 3c of the n-type drift semiconductor portion 3. The n-type channel semiconductor portion 5 is placed along the p+ type gate semiconductor portion 4 and is electrically connected to the fourth region 3d of the n-type drift semiconductor portion 3.Type: GrantFiled: July 24, 2003Date of Patent: October 16, 2007Assignee: Sumitomo Electric Industries, Ltd.Inventors: Takashi Hoshino, Shin Harada, Kazuhiro Fujikawa, Satoshi Hatsukawa, Kenichi Hirotsu
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Publication number: 20060202238Abstract: A lateral junction field effect transistor includes a first gate electrode layer arranged in a third semiconductor layer between source/drain region layers, having a lower surface extending on the second semiconductor layer, and doped with p-type impurities more heavily than the second semiconductor layer, and a second gate electrode layer arranged in a fifth semiconductor layer between the source/drain region layers, having a lower surface extending on a fourth semiconductor layer, having substantially the same concentration of p-type impurities as the first gate electrode layer, and having the same potential as the first gate electrode layer. Thereby, the lateral junction field effect transistor has a structure, which can reduce an on-resistance while maintaining good breakdown voltage properties.Type: ApplicationFiled: April 11, 2006Publication date: September 14, 2006Applicant: Sumitomo Electric Industries, Ltd.Inventors: Kazuhiro Fujikawa, Shin Harada, Kenichi Hirotsu, Satoshi Hatsukawa, Takashi Hoshino, Hiroyuki Matsunami, Tsunenobu Kimoto
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Publication number: 20060118813Abstract: A lateral JFET has a basic structure including an n-type semiconductor layer (3) formed of an n-type impurity region and a p-type semiconductor layer formed of a p-type impurity region on the n-type semiconductor layer (3). Moreover, in the p-type semiconductor layer, there are provided a p+-type gate region layer (7) extending into the n-type semiconductor layer (3) and containing p-type impurities of an impurity concentration higher than that of the n-type semiconductor layer (3) and an n+-type drain region layer (9) spaced from the p+-type gate region layer (7) by a predetermined distance and containing n-type impurities of an impurity concentration higher than that of the n-type semiconductor layer (3). With this structure, the lateral JFET can be provided that has an ON resistance further decreased while maintaining a high breakdown voltage performance.Type: ApplicationFiled: January 20, 2006Publication date: June 8, 2006Applicant: Sumitomo Electric Industries, Ltd.Inventors: Shin Harada, Kenichi Hirotsu, Hiroyuki Matsunami, Tsunenobu Kimoto
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Patent number: 7049644Abstract: A lateral junction field effect transistor includes a first gate electrode layer arranged in a third semiconductor layer between source/drain region layers, having a lower surface extending on the second semiconductor layer, and doped with p-type impurities more heavily than the second semiconductor layer, and a second gate electrode layer arranged in a fifth semiconductor layer between the source/drain region layers, having a lower surface extending on a fourth semiconductor layer, having substantially the same concentration of p-type impurities as the first gate electrode layer, and having the same potential as the first gate electrode layer. Thereby, the lateral junction field effect transistor has a structure, which can reduce an on-resistance while maintaining good breakdown voltage properties.Type: GrantFiled: December 2, 2002Date of Patent: May 23, 2006Assignee: Sumitomo Electric Industries, Ltd.Inventors: Kazuhiro Fujikawa, Shin Harada, Kenichi Hirotsu, Satoshi Hatsukawa, Takashi Hoshino, Hiroyuki Matsunami, Tsunenobu Kimoto
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Patent number: 7023033Abstract: A lateral JFET has a basic structure including an n-type semiconductor layer (3) formed of an n-type impurity region and a p-type semiconductor layer formed of a p-type impurity region on the n-type semiconductor layer (3). Moreover, in the p-type semiconductor layer, there are provided a p+-type gate region layer (7) extending into the n-type semiconductor layer (3) and containing p-type impurities of an impurity concentration higher than that of the n-type semiconductor layer (3) and an n+-type drain region layer (9) spaced from the p+-type gate region layer (7) by a predetermined distance and containing n-type impurities of an impurity concentration higher than that of the n-type semiconductor layer (3). With this structure, the lateral JFET can be provided that has an ON resistance further decreased while maintaining a high breakdown voltage performance.Type: GrantFiled: June 11, 2002Date of Patent: April 4, 2006Assignee: Sumitomo Electric Industries, Ltd.Inventors: Shin Harada, Kenichi Hirotsu, Hiroyuki Matsunami, Tsunenobu Kimoto
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Publication number: 20050230715Abstract: A vertical JFET 1a according to the present invention has an n+ type drain semiconductor portion 2, an n-type drift semiconductor portion 3, a p+ type gate semiconductor portion 4, an n-type channel semiconductor portion 5, an n+ type source semiconductor portion 7, and a p+ type gate semiconductor portion 8. The n-type drift semiconductor portion 3 is placed on a principal surface of the n+ type drain semiconductor portion 2 and has first to fourth regions 3a to 3d extending in a direction intersecting with the principal surface. The p+ type gate semiconductor portion 4 is placed on the first to third regions 3a to 3c of the n-type drift semiconductor portion 3. The n-type channel semiconductor portion 5 is placed along the p+ type gate semiconductor portion 4 and is electrically connected to the fourth region 3d of the n-type drift semiconductor portion 3.Type: ApplicationFiled: July 24, 2003Publication date: October 20, 2005Applicant: Sumitomo Electric Industries, Ltd.Inventors: Takashi Hoshino, Shin Harada, Kazuhiro Fujikawa, Satoshi Hatsukawa, Kenichi Hirotsu
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Publication number: 20050093017Abstract: A lateral junction field effect transistor includes a first gate electrode layer (18A) arranged in a third semiconductor layer (13) between source/drain region layers (6, 8), having a lower surface extending on the second semiconductor layer (12), and doped with p-type impurities more heavily than the second semiconductor layer (12), and a second gate electrode layer (18B) arranged in a fifth semiconductor layer (15) between the source/drain region layers (6, 8), having a lower surface extending on a fourth semiconductor layer (14), having substantially the same concentration of p-type impurities as the first gate electrode layer (18A), and having the same potential as the first gate electrode layer (18A). Thereby, the lateral junction field effect transistor has a structure, which can reduce an on-resistance while maintaining good breakdown voltage properties.Type: ApplicationFiled: December 2, 2002Publication date: May 5, 2005Inventors: Kazuhiro Fujikawa, Shin Harada, Kenichi Hirotsu, Satoshi Hatsukawa, Takashi Hoshino, Hiroyuki Matsunami, Tsunenobu Kimoto
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Patent number: 6870189Abstract: A junction field effect transistor (JFET) is provided that is capable of a high voltage resistance, high current switching operation, that operates with a low loss, and that has little variation. This JFET is provided with a gate region (2) of a second conductivity type provided on a surface of a semiconductor substrate, a source region (1) of a first conductivity type, a channel region (10) of the first conductivity type that adjoins the source region, a confining region (5) of the second conductivity type that adjoins the gate region and confines the channel region, a drain region (3) of the first conductivity type provided on a reverse face, and a drift region (4) of the first conductivity type that continuously lies in a direction of thickness of the substrate from a channel to a drain.Type: GrantFiled: September 11, 2000Date of Patent: March 22, 2005Assignee: Sumitomo Electric Industries, Ltd.Inventors: Shin Harada, Kenichi Hirotsu, Hiroyuki Matsunami, Tsunenobu Kimoto
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Publication number: 20050056872Abstract: A transverse JFET of SiC, employing an n+-type SiC substrate and comprising a channel region having carriers of high mobility, bringing a high yield is obtained. This transverse JFET has an n+-type SiC substrate, a p-type SiC film formed on a front face of the n+-type SiC substrate, an n-type SiC film, including a channel region, formed on the p-type SiC film, source and drain regions formed on the n-type SiC film separately on both sides of the channel region respectively, and a gate electrode provided on the SiC substrate or on the p-type SiC film.Type: ApplicationFiled: October 25, 2004Publication date: March 17, 2005Applicant: Sumitomo Electric Industries, Ltd.Inventors: Shin Harada, Kenichi Hirotsu
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Patent number: 6822275Abstract: A transverse JFET of SiC, employing an n-type SiC substrate and comprising a channel region having carriers of high mobility, bringing a high yield is obtained. This transverse JFET comprises an n-type SiC substrate (1n), a p-type SiC film (2) formed on the right face of the n-type SiC substrate, an n-type SiC film (3), including a channel region (11), formed on the p-type SiC film, source and drain regions (22, 23) formed on the n-type SiC film separately on both sides of the channel region respectively, and a gate electrode (14) provided in contact with the n-type SiC substrate (1n).Type: GrantFiled: June 19, 2002Date of Patent: November 23, 2004Assignee: Sumitomo Electric Industries, Ltd.Inventors: Shin Harada, Kenichi Hirotsu
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Publication number: 20030168704Abstract: A lateral JFET has a basic structure including an n-type semiconductor layer (3) formed of an n-type impurity region and a p-type semiconductor layer formed of a p-type impurity region on the n-type semiconductor layer (3). Moreover, in the p-type semiconductor layer, there are provided a p+-type gate region layer (7) extending into the n-type semiconductor layer (3) and containing p-type impurities of an impurity concentration higher than that of the n-type semiconductor layer (3) and an n+-type drain region layer (9) spaced from the p+-type gate region layer (7) by a predetermined distance and containing n-type impurities of an impurity concentration higher than that of the n-type semiconductor layer (3). With this structure, the lateral JFET can be provided that has an ON resistance further decreased while maintaining a high breakdown voltage performance.Type: ApplicationFiled: February 21, 2003Publication date: September 11, 2003Inventors: Shin Harada, Kenichi Hirotsu, Hiroyuki Matsunami, Tsunenobu Kimoto
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Publication number: 20020190258Abstract: A transverse JFET of SiC, employing an n-type SiC substrate and comprising a channel region having carriers of high mobility, bringing a high yield is obtained. This transverse JFET comprises an n-type SiC substrate (1n), a p-type SiC film (2) formed on the right face of the n-type SiC substrate, an n-type SiC film (3), including a channel region (11), formed on the p-type SiC film, source and drain regions (22, 23) formed on the n-type SiC film separately on both sides of the channel region respectively, and a gate electrode (14) provided in contact with the n-type SiC substrate (1n).Type: ApplicationFiled: June 19, 2002Publication date: December 19, 2002Inventors: Shin Harada, Kenichi Hirotsu