Patents by Inventor Kazushige Takaishi
Kazushige Takaishi 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).
-
Publication number: 20240055264Abstract: Provided is a wafer polishing method comprising: a step of determining a first correlation a second correlation; a step of calculating mechanical polishing rate/chemical polishing rate; a step of obtaining a relationship between the ratio of the mechanical polishing rate to the chemical polishing rate and one or more indications of wafer flatness and determining a specific range of the ratio of the mechanical polishing rate to the chemical polishing rate; a step of selecting a first target polishing solution that meets the specific range of the ratio of the mechanical polishing rate to the chemical polishing rate based on the first correlation and the second correlation; and a step of polishing wafers using the first target polishing solution. Also provided is a wafer production method including a step of performing a polishing process by the above wafer polishing method.Type: ApplicationFiled: October 28, 2021Publication date: February 15, 2024Applicant: SUMCO CorporationInventors: Chih Hao LIN, Kazushige TAKAISHI
-
Publication number: 20230201993Abstract: The sum of torques: the torque of the sun gear and the torque of the internal gear, and the ratio of the torques are controlled within predetermined ranges.Type: ApplicationFiled: February 5, 2021Publication date: June 29, 2023Applicant: SUMCO CORPORATIONInventors: Kazushige TAKAISHI, Chin Fu TSAI
-
Patent number: 9190267Abstract: Provided is an epitaxial silicon wafer in which the warping is reduced by rendering a cross-sectional form of a silicon wafer for epitaxial growth into an adequate form as compared with the conventional one. An epitaxial silicon wafer comprising a silicon wafer for epitaxial growth and an epitaxial layer is characterized in that the epitaxial layer is formed on a silicon wafer for epitaxial growth having a cross-sectional form satisfying a relation of a given expression.Type: GrantFiled: November 10, 2011Date of Patent: November 17, 2015Assignee: SUMCO CorporationInventors: Takayuki Kihara, Kazushige Takaishi, Yasuyuki Hashimoto
-
Patent number: 8900033Abstract: An object of the present invention is to provide a method of polishing silicon wafers, capable of suppressing generation of undesired sounds from carriers and reducing the thickness variation of the wafers after polished. The method is a wafer polishing method in which wafers 20 are polished by supplying a polishing solution to surfaces 30a of a pair of polishing pads 30 positioned above and below carriers 10 each having a circular hole 11 for retaining the wafers 20, the carriers 10 being thinner than the wafers 20; and sliding the polishing pads 30 relatively to the carriers 10, thereby simultaneously polishing both surfaces of the wafers 20 retained in the carriers 10. The method is characterized in that information sourced from the carriers 10 when a difference between the thickness of the carriers 10 and the thickness of the wafers 20 reaches a predetermined value is detected to calculate the thickness of the wafers 20, thereby terminating polishing.Type: GrantFiled: November 30, 2010Date of Patent: December 2, 2014Assignee: Sumco CorporationInventors: Kazushige Takaishi, Keiichi Takanashi, Tetsurou Taniguchi, Shinichi Ogata, Shunsuke Mikuriya
-
Patent number: 8759229Abstract: A method for manufacturing an epitaxial wafer that can reduce occurrence of a surface defect or a slip formed on an epitaxial layer is provided. The manufacturing method is characterized by comprising: a smoothing step of controlling application of an etchant to a wafer surface in accordance with a surface shape of a silicon wafer to smooth the wafer surface; and an epitaxial layer forming step of forming an epitaxial layer formed of a silicon single crystal on the surface of the wafer based on epitaxial growth.Type: GrantFiled: January 24, 2007Date of Patent: June 24, 2014Assignee: Sumco CorporationInventors: Sakae Koyata, Kazushige Takaishi, Tomohiro Hashii, Katsuhiko Murayama, Takeo Katoh
-
Patent number: 8728942Abstract: Mirror-polishing a front surface of a silicon wafer using polishing liquid composed of an abrasive grain-free alkaline solution including water-soluble polymers simplifies a polishing process, thus leading to an increase in productivity and a reduction in cost, and reduces the density of LPDs attributable to processing and occurring in the front surface of a mirror-polished wafer, thus improving the surface roughness of the wafer front surface.Type: GrantFiled: August 20, 2010Date of Patent: May 20, 2014Assignee: Sumico CorporationInventors: Shinichi Ogata, Kazushige Takaishi, Hironori Nishimura, Shigeru Okuuchi, Shunsuke Mikuriya, Yuichi Nakayoshi
-
Patent number: 8466071Abstract: An object of the present invention is to provide a method for etching a single wafer, which effectively realizes a high flatness of wafer and an increase in productivity thereof. In a method for etching a single wafer, a single thin disk-like wafer sliced from a silicon single crystal ingot is spun, and a front surface of the wafer is etched with an etching solution supplied thereto. In the method, a plurality of supply nozzles are disposed above and opposite to the front surface of the wafer at different portions in the radial direction of the wafer, respectively; and then one or more conditions selected from the group consisting of temperatures, kinds, and supply flow rates of etching solutions from the plurality of supply nozzles are changed.Type: GrantFiled: January 24, 2007Date of Patent: June 18, 2013Assignee: Sumco CorporationInventors: Sakae Koyata, Tomohiro Hashii, Katsuhiko Murayama, Kazushige Takaishi, Takeo Katoh
-
Publication number: 20130017763Abstract: An object of the present invention is to provide a method of polishing silicon wafers, capable of suppressing generation of undesired sounds from carriers and reducing the thickness variation of the wafers after polished. The method is a wafer polishing method in which wafers 20 are polished by supplying a polishing solution to surfaces 30a of a pair of polishing pads 30 positioned above and below carriers 10 each having a circular hole 11 for retaining the wafers 20, the carriers 10 being thinner than the wafers 20; and sliding the polishing pads 30 relatively to the carriers 10, thereby simultaneously polishing both surfaces of the wafers 20 retained in the carriers 10. The method is characterized in that information sourced from the carriers 10 when a difference between the thickness of the carriers 10 and the thickness of the wafers 20 reaches a predetermined value is detected to calculate the thickness of the wafers 20, thereby terminating polishing.Type: ApplicationFiled: November 30, 2010Publication date: January 17, 2013Inventors: Kazushige Takaishi, Keiichi Takanashi, Tetsurou Taniguchi, Shinichi Ogata, Shunsuke Mikuriya
-
Publication number: 20120156878Abstract: Mirror-polishing a front surface of a silicon wafer using polishing liquid composed of an abrasive grain-free alkaline solution including water-soluble polymers simplifies a polishing process, thus leading to an increase in productivity and a reduction in cost, and reduces the density of LPDs attributable to processing and occurring in the front surface of a mirror-polished wafer, thus improving the surface roughness of the wafer front surface.Type: ApplicationFiled: August 20, 2010Publication date: June 21, 2012Applicant: SUMCO CORPORATIONInventors: Shinichi Ogata, Kazushige Takaishi, Hironori Nishimura, Shigeru Okuuchi, Shunsuke Mikuriya, Yuichi Nakayoshi
-
Patent number: 8147295Abstract: A silicon wafer is polished by applying a polishing solution substantially containing no abrasive grain onto a surface of a polishing pad having a given fixed grain bonded abrasive and then relatively sliding the polishing pad to a silicon wafer to polish the surface of the silicon wafer, wherein a hydroplane layer is formed by the polishing solution supplied between the surface of the silicon wafer and the surface of the polishing pad and a thickness of the hydroplane layer is controlled to change a polishing state of the surface of the silicon wafer.Type: GrantFiled: May 27, 2009Date of Patent: April 3, 2012Assignee: Sumco CorporationInventors: Takeo Katoh, Ryuichi Tanimoto, Shinichi Ogata, Takeru Takushima, Kazushige Takaishi
-
Publication number: 20120056307Abstract: Provided is an epitaxial silicon wafer in which the warping is reduced by rendering a cross-sectional form of a silicon wafer for epitaxial growth into an adequate form as compared with the conventional one. An epitaxial silicon wafer comprising a silicon wafer for epitaxial growth and an epitaxial layer is characterized in that the epitaxial layer is formed on a silicon wafer for epitaxial growth having a cross-sectional form satisfying a relation of a given expression.Type: ApplicationFiled: November 10, 2011Publication date: March 8, 2012Applicant: SUMCO CORPORATIONInventors: Takayuki Kihara, Kazushige Takaishi, Yasuyuki Hashimoto
-
Patent number: 8080106Abstract: Provided are an epitaxial silicon wafer in which the warping is reduced by rendering a cross-sectional form of a silicon wafer for epitaxial growth into an adequate form as compared with the conventional one, and a production method thereof. An epitaxial silicon wafer comprising a silicon wafer for epitaxial growth and an epitaxial layer is characterized in that the epitaxial layer is formed on a silicon wafer for epitaxial growth having a cross-sectional form satisfying a relation of a given expression.Type: GrantFiled: July 20, 2009Date of Patent: December 20, 2011Assignee: Sumco CorporationInventors: Takayuki Kihara, Kazushige Takaishi, Yasuyuki Hashimoto
-
Patent number: 8066896Abstract: An apparatus for etching a wafer by a single-wafer process comprises a fluid supplying device which feeds an etching fluid on a wafer, and a wafer-chuck for horizontally holding the wafer. The wafer-chuck is equipped with a gas injection device for injecting a gas to the wafer, a first fluid-aspirating device, and a second fluid-aspirating device. The etching fluid supplied on the wafer is spread by a rotation of the wafer. The etching fluid is scattered by a centrifugal force, or flows down over an edge portion of the wafer and is blown-off by the gas injected from the gas injection unit, and is aspirated by the first fluid-aspirating device or the second fluid-aspirating device.Type: GrantFiled: August 15, 2007Date of Patent: November 29, 2011Assignee: Sumco CorporationInventors: Sakae Koyata, Tomohiro Hashii, Katsuhiko Murayama, Kazushige Takaishi, Takeo Katoh
-
Patent number: 7998867Abstract: An epitaxial wafer is provided capable of eliminating particles in a device process, particles being generated from a scratch in a boundary area between a rear surface and a chamfered surface of a wafer. The scratch in the boundary area between the rear surface and the chamfered surface is removed in a scratch removal process. Thus, no particles exist caused by a scratch, at a time of immersion in an etching solution in the device process, and thus a device yield is increased.Type: GrantFiled: November 6, 2008Date of Patent: August 16, 2011Assignee: Sumco CorporationInventors: Kazushige Takaishi, Tomonori Miura
-
Patent number: 7955440Abstract: After a water film is formed on a wafer front surface in a chamber, the water film is supplied sequentially with an oxidizing component of an oxidation gas, an organic acid component of an organic acid mist, an HF component of an HF gas, the organic acid mist, and the oxidizing component of the oxidation gas. As a result, the HF component and the organic acid component provide cleaning effect on the wafer surface, and a concentration of the cleaning components in the water film within a wafer surface can be even.Type: GrantFiled: November 21, 2008Date of Patent: June 7, 2011Assignee: Sumco CorporationInventors: Shigeru Okuuchi, Kazushige Takaishi
-
Patent number: 7955982Abstract: Disclosed is a method for smoothing the surface of at least one side of a wafer which is obtained by slicing a semiconductor ingot. In this method, a fluid is applied according to projections of the wafer surface, thereby reducing the projections. Alternatively, a fluid is applied over the wafer surface, thereby smoothing the entire surface of the wafer while reducing the projections in the wafer surface.Type: GrantFiled: January 17, 2007Date of Patent: June 7, 2011Assignee: Sumco CorporationInventors: Takeo Katoh, Tomohiro Hashii, Katsuhiko Murayama, Sakae Koyata, Kazushige Takaishi
-
Patent number: 7906438Abstract: An object of the present invention is to provide a single wafer etching apparatus realizing a high flatness of wafers and an increase in productivity thereof. In the single wafer etching apparatus, a single thin disk-like wafer sliced from a silicon single crystal ingot is mounted on a wafer chuck and spun thereon, and an overall front surface of the wafer is etched with an etching solution supplied thereto by centrifugal force generated by spinning the wafer 11. The singe wafer etching apparatus includes a plurality of supply nozzles 26, 27 capable of discharging the etching solution 14 from discharge openings 26a, 27a onto the front surface of the wafer 11, nozzle-moving devices each capable of independently moving the plurality of supply nozzles 28, 29, and an etching solution supplying device 30 for supplying the etching solution 14 to each of the plurality of supply nozzles and discharging the etching solution 14 from each of the discharge openings to the front surface of the wafer 11.Type: GrantFiled: January 31, 2007Date of Patent: March 15, 2011Assignee: Sumco CorporationInventors: Sakae Koyata, Tomohiro Hashii, Katsuhiko Murayama, Kazushige Takaishi, Takeo Katoh
-
Patent number: 7851375Abstract: An alkali etchant for controlling surface roughness of a semiconductor wafer, which is a sodium hydroxide solution or a potassium hydroxide solution having a weight concentration of 55 wt % to 70 wt %.Type: GrantFiled: March 25, 2005Date of Patent: December 14, 2010Assignee: Sumco CorporationInventors: Sakae Koyata, Kazushige Takaishi
-
Publication number: 20100261341Abstract: An epitaxial wafer is provided capable of eliminating particles in a device process, particles being generated from a scratch in a boundary area between a rear surface and a chamfered surface of a wafer. The scratch in the boundary area between the rear surface and the chamfered surface is removed in a scratch removal process. Thus, no particles exist caused by a scratch, at a time of immersion in an etching solution in the device process, and thus a device yield is increased.Type: ApplicationFiled: November 6, 2008Publication date: October 14, 2010Applicant: SUMCO CORPORATIONInventors: Kazushige Takaishi, Tomonori Miura
-
Publication number: 20100252070Abstract: After a water film is formed on a wafer front surface in a chamber, the water film is supplied sequentially with an oxidizing component of an oxidation gas, an organic acid component of an organic acid mist, an HF component of an HF gas, the organic acid mist, and the oxidizing component of the oxidation gas. As a result, the HF component and the organic acid component provide cleaning effect on the wafer surface, and a concentration of the cleaning components in the water film within a wafer surface can be even.Type: ApplicationFiled: November 21, 2008Publication date: October 7, 2010Applicant: SUMCO CORPORATIONInventors: Shigeru Okuuchi, Kazushige Takaishi