Patents by Inventor Yasushi Miyasaka
Yasushi Miyasaka 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: 9018633Abstract: A semiconductor device includes an active region in which current flows when the semiconductor device is in an on state and a breakdown voltage structure portion which surrounds the active region. In the active region, a MOS gate structure includes, a p well region, an n+ source region, a gate electrode, and a source electrode is provided on the front surface of a semiconductor substrate. A drain electrode which comes into contact with an n? drift region is provided from the rear surface to the side surface of the semiconductor substrate. The drain electrode forms a Schottky contact with the n? drift region which is the semiconductor substrate. In the breakdown voltage structure portion, a leakage current reducing layer reduces leakage current from the outer circumferential edge of the semiconductor substrate and is provided at least at the outer circumferential edge of the semiconductor substrate.Type: GrantFiled: August 12, 2013Date of Patent: April 28, 2015Assignee: Fuji Electric Co., Ltd.Inventors: Hiroki Wakimoto, Haruo Nakazawa, Yasushi Miyasaka
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Publication number: 20140061672Abstract: A semiconductor device includes an active region in which current flows when the semiconductor device is in an on state and a breakdown voltage structure portion which surrounds the active region. In the active region, a MOS gate structure includes, a p well region, an n+ source region, a gate electrode, and a source electrode is provided on the front surface of a semiconductor substrate. A drain electrode which comes into contact with an n? drift region is provided from the rear surface to the side surface of the semiconductor substrate. The drain electrode forms a Schottky contact with the n? drift region which is the semiconductor substrate. In the breakdown voltage structure portion, a leakage current reducing layer reduces leakage current from the outer circumferential edge of the semiconductor substrate and is provided at least at the outer circumferential edge of the semiconductor substrate.Type: ApplicationFiled: August 12, 2013Publication date: March 6, 2014Applicant: FUJI ELECTRIC CO., LTD.Inventors: Hiroki WAKIMOTO, Haruo NAKAZAWA, Yasushi MIYASAKA
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Patent number: 7507023Abstract: A temperature measurement device of a power semiconductor device includes a plurality of temperature detecting diodes formed on a first chip having a power semiconductor device; and a detection circuit that is formed on a second chip having an integrated circuit that controls the power semiconductor device and is connected to the temperature detecting diodes; wherein the detection circuit detects a temperature of the power semiconductor device based on a difference between the forward voltages of the temperature detecting diodes when different values of current flow to the respective temperature detecting diodes.Type: GrantFiled: April 14, 2006Date of Patent: March 24, 2009Assignee: Fuji Electric Device Technology Co., Ltd.Inventors: Kazunori Oyabe, Tomoyuki Yamazaki, Yasushi Miyasaka
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Patent number: 7282781Abstract: A semiconductor device has an n?-semiconductor layer and p+-diffusion regions each having a depth of 14 to 20 ?m (design value) selectively formed in the n? semiconductor layer. With the entire surface of the chip irradiated with light ions, such as He ions, a lifetime killer is introduced from a position d2 shallower than a position d1 of a p-n junction surface, formed from the n?-semiconductor layer and the p+-diffusion regions, to a position d3 deeper than the position d1 to form a short-lifetime region over the entire chip. The irradiation is carried out so that the light ion irradiation half width is not more than the depth of the p+-diffusion regions and a position of a peak of the light ions becomes deeper than the light ion irradiation half width and within the range between 80% and 120% of the depth of the p+-diffusion regions.Type: GrantFiled: March 15, 2005Date of Patent: October 16, 2007Assignee: Fuji Electric Device Technology Co., Ltd.Inventors: Toshiyuki Matsui, Yasuyuki Hoshi, Yasuyuki Kobayashi, Yasushi Miyasaka
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Patent number: 7276771Abstract: A diode is provided which includes a first-conductivity-type cathode layer, a first-conductivity-type drift layer placed on the cathode region and having a lower concentration than the cathode layer, a generally ring-like second-conductivity-type ring region formed in the drift layer, second-conductivity-type anode region formed in the drift layer located inside the ring region, a cathode electrode formed in contact with the cathode layer, and an anode electrode formed in contact with the anode region, wherein the lowest resistivity of the second-conductivity-type anode region is at least 1/100 of the resistivity of the drift layer, and the thickness of the anode region is smaller than the diffusion depth of the ring region.Type: GrantFiled: June 23, 2006Date of Patent: October 2, 2007Assignee: Fuji Electric Co., Ltd.Inventors: Tatsuhiko Fujihira, Yasushi Miyasaka
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Patent number: 7187054Abstract: A diode is provided which includes a first-conductivity-type cathode layer, a first-conductivity-type drift layer placed on the cathode region and having a lower concentration than the cathode layer, a generally ring-like second-conductivity-type ring region formed in the drift layer, second-conductivity-type anode region formed in the drift layer located inside the ring region, a cathode electrode formed in contact with the cathode layer, and an anode electrode formed in contact with the anode region, wherein the lowest resistivity of the second-conductivity-type anode region is at least 1/100 of the resistivity of the drift layer, and the thickness of the anode region is smaller than the diffusion depth of the ring region.Type: GrantFiled: March 4, 2005Date of Patent: March 6, 2007Assignee: Fuji Electric Holdings Co., Ltd.Inventors: Tatsuhiko Fujihira, Yasushi Miyasaka
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Publication number: 20060255361Abstract: A temperature measurement device of a power semiconductor device includes a plurality of temperature detecting diodes formed on a first chip having a power semiconductor device; and a detection circuit that is formed on a second chip having an integrated circuit that controls the power semiconductor device and is connected to the temperature detecting diodes; wherein the detection circuit detects a temperature of the power semiconductor device based on a difference between the forward voltages of the temperature detecting diodes when different values of current flow to the respective temperature detecting diodes.Type: ApplicationFiled: April 14, 2006Publication date: November 16, 2006Inventors: Kazunori Oyabe, Tomoyuki Yamazaki, Yasushi Miyasaka
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Publication number: 20060244006Abstract: A diode is provided which includes a first-conductivity-type cathode layer, a first-conductivity-type drift layer placed on the cathode region and having a lower concentration than the cathode layer, a generally ring-like second-conductivity-type ring region formed in the drift layer, second-conductivity-type anode region formed in the drift layer located inside the ring region, a cathode electrode formed in contact with the cathode layer, and an anode electrode formed in contact with the anode region, wherein the lowest resistivity of the second-conductivity-type anode region is at least 1/100 of the resistivity of the drift layer, and the thickness of the anode region is smaller than the diffusion depth of the ring region.Type: ApplicationFiled: June 23, 2006Publication date: November 2, 2006Applicant: Fuji Electric Holdings Co., Ltd.Inventors: Tatsuhiko Fujihira, Yasushi Miyasaka
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Patent number: 7112865Abstract: A diode is provided which includes a first-conductivity-type cathode layer, a first-conductivity-type drift layer placed on the cathode region and having a lower concentration than the cathode layer, a generally ring-like second-conductivity-type ring region formed in the drift layer, second-conductivity-type anode region formed in the drift layer located inside the ring region, a cathode electrode formed in contact with the cathode layer, and an anode electrode formed in contact with the anode region, wherein the lowest resistivity of the second-conductivity-type anode region is at least 1/100 of the resistivity of the drift layer, and the thickness of the anode region is smaller than the diffusion depth of the ring region.Type: GrantFiled: March 3, 2005Date of Patent: September 26, 2006Assignee: Fuji Electric Holdings Co., Ltd.Inventors: Tatsuhiko Fujihira, Yasushi Miyasaka
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Patent number: 6975013Abstract: A diode is provided which includes a first-conductivity-type cathode layer, a first-conductivity-type drift layer placed on the cathode region and having a lower concentration than the cathode layer, a generally ring-like second-conductivity-type ring region formed in the drift layer, second-conductivity-type anode region formed in the drift layer located inside the ring region, a cathode electrode formed in contact with the cathode layer, and an anode electrode formed in contact with the anode region, wherein the lowest resistivity of the second-conductivity-type anode region is at least 1/100 of the resistivity of the drift layer, and the thickness of the anode region is smaller than the diffusion depth of the ring region.Type: GrantFiled: October 2, 2002Date of Patent: December 13, 2005Assignee: Fuji Electric Co., Ltd.Inventors: Tatsuhiko Fujihira, Yasushi Miyasaka
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Publication number: 20050263842Abstract: A semiconductor device has an n?-semiconductor layer and p+-diffusion regions each having a depth of 14 to 20 ?m (design value) selectively formed in the n? semiconductor layer. With the entire surface of the chip irradiated with light ions, such as He ions, a lifetime killer is introduced from a position d2 shallower than a position d1 of a p-n junction surface, formed from the n?-semiconductor layer and the p+-diffusion regions, to a position d3 deeper than the position d1 to form a short-lifetime region over the entire chip. The irradiation is carried out so that the light ion irradiation half width is not more than the depth of the p+-diffusion regions and a position of a peak of the light ions becomes deeper than the light ion irradiation half width and within the range between 80% and 120% of the depth of the p+-diffusion regions.Type: ApplicationFiled: March 15, 2005Publication date: December 1, 2005Applicant: Fuji Electric DeviceInventors: Toshiyuki Matsui, Yasuyuki Hoshi, Yasuyuki Kobayashi, Yasushi Miyasaka
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Publication number: 20050179105Abstract: A diode is provided which includes a first-conductivity-type cathode layer, a first-conductivity-type drift layer placed on the cathode region and having a lower concentration than the cathode layer, a generally ring-like second-conductivity-type ring region formed in the drift layer, second-conductivity-type anode region formed in the drift layer located inside the ring region, a cathode electrode formed in contact with the cathode layer, and an anode electrode formed in contact with the anode region, wherein the lowest resistivity of the second-conductivity-type anode region is at least 1/100 of the resistivity of the drift layer, and the thickness of the anode region is smaller than the diffusion depth of the ring region.Type: ApplicationFiled: March 3, 2005Publication date: August 18, 2005Applicant: Fuji Electric Holdings Co., Ltd.Inventors: Tatsuhiko Fujihira, Yasushi Miyasaka
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Publication number: 20050151219Abstract: A diode is provided which includes a first-conductivity-type cathode layer, a first-conductivity-type drift layer placed on the cathode region and having a lower concentration than the cathode layer, a generally ring-like second-conductivity-type ring region formed in the drift layer, second-conductivity-type anode region formed in the drift layer located inside the ring region, a cathode electrode formed in contact with the cathode layer, and an anode electrode formed in contact with the anode region, wherein the lowest resistivity of the second-conductivity-type anode region is at least {fraction (1/100)} of the resistivity of the drift layer, and the thickness of the anode region is smaller than the diffusion depth of the ring region.Type: ApplicationFiled: March 4, 2005Publication date: July 14, 2005Applicant: Fuji Electric Holdings Co., Ltd.Inventors: Tatsuhiko Fujihira, Yasushi Miyasaka
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Patent number: 6815766Abstract: A semiconductor device has an alternating conductivity type layer that improves the tradeoff relation between the ON-resistance and the breakdown voltage and a method of manufacturing such a semiconductor device. The alternating conductivity type layer is formed of n-type drift regions and p-type partition regions alternately arranged with each other. At least the n-type drift regions or p-type partition regions are formed by ion implantation under an acceleration voltage changed continuously. The p-type partition regions or n-type drift regions are formed by epitaxial growth or by diffusing impurities from the surface of a substrate or a layer for the layer.Type: GrantFiled: April 21, 2003Date of Patent: November 9, 2004Assignee: Fuji Electric Co., Ltd.Inventors: Yasushi Miyasaka, Tatsuhiko Fujihira
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Patent number: 6787420Abstract: This invention clarifies the effects of parameters and enables the mass production of a super-junction semiconductor device, which has a drift layer composed of a parallel pn layer that conducts electricity in the ON state and is depleted in the OFF state. The quantity of impurities in n drift regions is within the range between 100% and 150% or between 110% and 150% of the quantity of impurities in p partition regions. The impurity density of either one of the n drift regions and the p partition regions is within the range between 92% and 108% of the impurity density of the other regions. In addition, the width of either one of the n drift regions and the p partition regions is within the range between 94% and 106% of the width of the other regions.Type: GrantFiled: July 16, 2001Date of Patent: September 7, 2004Assignee: Fuji Electric Co., Ltd.Inventors: Yasushi Miyasaka, Tatsuhiko Fujihira, Yasuhiko Ohnishi, Katsunori Ueno, Susumu Iwamoto
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Patent number: 6677626Abstract: This invention achieves a high inverse voltage of a super-junction semiconductor device, which has a drift layer composed of a parallel pn layer that conducts electricity in the ON state and is depleted in the OFF state. An n− high resistance region is formed at the periphery of a drift layer composed of a parallel pn layer of n drift regions and p partition regions. The impurity density ND of the n− high resistance region is 5.62×1017×VDSS−1.36(cm−3) or less. VDSS denotes the withstand voltage (V). An n low resistance region is arranged adjacent to the n− high resistance region.Type: GrantFiled: November 10, 1999Date of Patent: January 13, 2004Assignee: Fuji Electric Co., Ltd.Inventors: Youichi Shindou, Yasushi Miyasaka, Tatsuhiko Fujihira, Manabu Takei
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Patent number: 6673679Abstract: A semiconductor device has an alternating conductivity type layer that improves the tradeoff relation between the ON-resistance and the breakdown voltage and a method of manufacturing such a semiconductor device. The alternating conductivity type layer is formed of n-type drift regions and p-type partition regions alternately arranged with each other. At least the n-type drift regions or p-type partition regions are formed by ion implantation under an acceleration voltage changed continuously. The p-type partition regions or n-type drift regions are formed by epitaxial growth or by diffusing impurities from the surface of a substrate or a layer for the layer.Type: GrantFiled: January 11, 2000Date of Patent: January 6, 2004Assignee: Fuji Electric Co., Ltd.Inventors: Yasushi Miyasaka, Tatsuhiko Fujihira
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Publication number: 20030207536Abstract: To provide a semiconductor device with an alternating conductivity type layer that facilitates improves the tradeoff relation between the ON-resistance and the breakdown voltage and increasing the current capacity by reducing the ON-resistance while maintaining the high breakdown voltage, and to provide a method of manufacturing the semiconductor device with an alternating conductivity type layer easily and with excellent mass productivity. The semiconductor device according to the invention includes an alternating conductivity type layer that provides a current path in the ON-state of the device and is depleted in the OFF-state of the device. The alternating conductivity type layer is formed of n-type drift regions and p-type partition regions alternately arranged with each other. At least, n-type drift regions or p-type partition regions are formed by ion implantation under an acceleration voltage changed continuously.Type: ApplicationFiled: April 21, 2003Publication date: November 6, 2003Applicant: Fuji Electric, Co., Ltd.Inventors: Yasushi Miyasaka, Tatsuhiko Fujihira
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Publication number: 20030030120Abstract: A diode is provided which includes a first-conductivity-type cathode layer, a first-conductivity-type drift layer placed on the cathode region and having a lower concentration than the cathode layer, a generally ring-like second-conductivity-type ring region formed in the drift layer, second-conductivity-type anode region formed in the drift layer located inside the ring region, a cathode electrode formed in contact with the cathode layer, and an anode electrode formed in contact with the anode region, wherein the lowest resistivity of the second-conductivity-type anode region is at least {fraction (1/100)} of the resistivity of the drift layer, and the thickness of the anode region is smaller than the diffusion depth of the ring region.Type: ApplicationFiled: October 2, 2002Publication date: February 13, 2003Applicant: Fuji Electric Co., Ltd.Inventors: Tatsuhiko Fujihira, Yasushi Miyasaka
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Patent number: 6383836Abstract: A diode is provided which includes a first-conductivity-type cathode layer, a first-conductivity-type drift layer placed on the cathode region and having a lower concentration than the cathode layer, a generally ring-like second-conductivity-type ring region formed in the drift layer, second-conductivity-type anode region formed in the drift layer located inside the ring region, a cathode electrode formed in contact with the cathode layer, and an anode electrode formed in contact with the anode region, wherein the lowest resistivity of the second-conductivity-type anode region is at least {fraction (1/100)} of the resistivity of the drift layer, and the thickness of the anode region is smaller than the diffusion depth of the ring region.Type: GrantFiled: February 26, 2001Date of Patent: May 7, 2002Assignee: Fuji Electric Co., Ltd.Inventors: Tatsuhiko Fujihira, Yasushi Miyasaka