Patents by Inventor Kazuaki Kozasa
Kazuaki Kozasa 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: 11628534Abstract: A silicon wafer single-side polishing method that can significantly improve the stepped minute defect occurrence rate is provided. The silicon wafer single-side polishing method comprises: a first polishing step of performing polishing on one side of a silicon wafer under a first polishing condition; and a second polishing step of performing polishing on the silicon wafer under a second polishing condition in which at least one of an applied pressure and a relative speed in the first polishing condition is changed, after the first polishing step, wherein a polishing rate ratio according to the first polishing condition is higher than a polishing rate ratio according to the second polishing condition.Type: GrantFiled: December 2, 2016Date of Patent: April 18, 2023Assignee: SUMCO CORPORATIONInventors: Toshiharu Nakajima, Kazuaki Kozasa, Katsuhisa Sugimori, Syunya Kobuchi
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Patent number: 11554458Abstract: A polishing head of a wafer polishing apparatus is provided with: a membrane head that can independently control a center control pressure pressing a center portion of a wafer, and an outer periphery control pressure pressing an outer peripheral portion of the wafer; an outer ring integrated with the membrane head so as to configure the outer peripheral portion of the membrane head; and a contact type retainer ring provided outside the membrane head. The membrane head has a central pressure chamber of a single compartment structure that controls the center control pressure, and an outer peripheral pressure chamber that is provided above the central pressure chamber, and that controls the outer periphery control pressure. A position of a lower end of the outer ring reaches at least a position of an inner bottom surface of the central pressure chamber.Type: GrantFiled: February 13, 2019Date of Patent: January 17, 2023Assignee: SUMCO CORPORATIONInventors: Yuki Nakano, Katsuhisa Sugimori, Kazuaki Kozasa, Jiro Kajiwara, Katsutoshi Yamamoto, Takayuki Kihara, Ryoya Terakawa
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Publication number: 20220415666Abstract: Provided is a wafer polishing method capable of improving nanotopography characteristics within a site on the surface of a wafer having a 2 mm square area or a small area equivalent thereto and a silicon wafer polished by the wafer polishing method, and further provided is a method of chemical-mechanical polishing the surface of a wafer through a polishing step in two or more polishing steps with different polishing rates, in which the in-plane thickness variation (standard deviation) of a polishing pad 150 used in a polishing step with a machining allowance of 0.3 ?m or more is 2.0 ?m or less.Type: ApplicationFiled: October 21, 2020Publication date: December 29, 2022Applicant: SUMCO CORPORATIONInventors: Kazuaki KOZASA, Katsuhisa SUGIMORI, Kazuki NISHIOKA, Tsuyoshi MORITA
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Patent number: 11211285Abstract: In a method of producing a bonded wafer, the amount of depression of the polishing cloth is 50 ?m to 90 ?m, and the surface hardness (ASKER C) of the polishing cloth is 50 to 60. In the bonded wafer, the polycrystalline silicon layer has a thickness variation ?t of 5% or less, and the support substrate wafer has a GBIR of 0.2 ?m or less and an SFQR of 0.06 ?m or less after the polycrystalline silicon layer is polished.Type: GrantFiled: January 8, 2019Date of Patent: December 28, 2021Assignee: SUMCO CORPORATIONInventors: Youzou Satou, Kazuaki Kozasa
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Publication number: 20210331285Abstract: A polishing head of a wafer polishing apparatus is provided with: a membrane head that can independently control a center control pressure pressing a center portion of a wafer, and an outer periphery control pressure pressing an outer peripheral portion of the wafer; an outer ring integrated with the membrane head so as to configure the outer peripheral portion of the membrane head; and a contact type retainer ring provided outside the membrane head. The membrane head has a central pressure chamber of a single compartment structure that controls the center control pressure, and an outer peripheral pressure chamber that is provided above the central pressure chamber, and that controls the outer periphery control pressure. A position of a lower end of the outer ring reaches at least a position of an inner bottom surface of the central pressure chamber.Type: ApplicationFiled: February 13, 2019Publication date: October 28, 2021Applicant: SUMCO CORPORATIONInventors: Yuki NAKANO, Katsuhisa SUGIMORI, Kazuaki KOZASA, Jiro KAJIWARA, Katsutoshi YAMAMOTO, Takayuki KIHARA, Ryoya TERAKAWA
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Publication number: 20200343130Abstract: In a method of producing a bonded wafer, the amount of depression of the polishing cloth is 50 ?m to 90 ?m, and the surface hardness (ASKER C) of the polishing cloth is 50 to 60. In the bonded wafer, the polycrystalline silicon layer has a thickness variation ?t of 5% or less, and the support substrate wafer has a GBIR of 0.2 ?m or less and an SFQR of 0.06 ?m or less after the polycrystalline silicon layer is polished.Type: ApplicationFiled: January 8, 2019Publication date: October 29, 2020Applicant: SUMCO CorporationInventors: Youzou SATOU, Kazuaki KOZASA
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Publication number: 20190030676Abstract: A silicon wafer single-side polishing method that can significantly improve the stepped minute defect occurrence rate is provided. The silicon wafer single-side polishing method comprises: a first polishing step of performing polishing on one side of a silicon wafer under a first polishing condition; and a second polishing step of performing polishing on the silicon wafer under a second polishing condition in which at least one of an applied pressure and a relative speed in the first polishing condition is changed, after the first polishing step, wherein a polishing rate ratio according to the first polishing condition is higher than a polishing rate ratio according to the second polishing condition.Type: ApplicationFiled: December 2, 2016Publication date: January 31, 2019Applicant: SUMCO CORPORATIONInventors: Toshiharu NAKAJIMA, Kazuaki KOZASA, Katsuhisa SUGIMORI, Syunya KOBUCHI
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Patent number: 9991110Abstract: A mirror-finishing chamfer polishing is applied using an abrasive-grain-free polishing solution to a chamfered portion of a semiconductor wafer having an oxide film on a top side or the top and bottom sides of the semiconductor wafer and having no oxide film on the chamfered portion. Further, prior to the mirror-finishing chamfer polishing, a pre-finish mirror chamfer polishing is applied using an abrasive-grain-containing polishing solution to the chamfered portion of the semiconductor wafer having the oxide film on the top side or the top and bottom sides and on the chamfered portion.Type: GrantFiled: November 19, 2014Date of Patent: June 5, 2018Assignee: SUMCO CORPORATIONInventors: Kazuaki Kozasa, Syunya Kobuchi, Katsuhisa Sugimori
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Patent number: 9956663Abstract: A method of a polishing a wafer includes: a first polishing step of polishing a surface of the wafer while supplying a rough polishing liquid onto a polishing surface of a rough polishing cloth; subsequent to the first polishing step, a protection film formation step of supplying a protection film formation solution containing a water-soluble polymer to the rough polishing cloth after being used in the first polishing step and bringing the protection film formation solution into contact with the polished surface of the wafer to form a protection film on the polished surface; and a second polishing step of polishing the surface of the wafer where the protection film is formed while supplying a finish polishing liquid to a polishing surface of a finish polishing cloth different from the rough polishing cloth.Type: GrantFiled: May 13, 2015Date of Patent: May 1, 2018Assignee: SUMCO CORPORATIONInventors: Kazuaki Kozasa, Katsuhisa Sugimori, Syunya Kobuchi
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Publication number: 20170252891Abstract: A method of a polishing a wafer includes: a first polishing step of polishing a surface of the wafer while supplying a rough polishing liquid onto a polishing surface of a rough polishing cloth; subsequent to the first polishing step, a protection film formation step of supplying a protection film formation solution containing a water-soluble polymer to the rough polishing cloth after being used in the first polishing step and bringing the protection film formation solution into contact with the polished surface of the wafer to form a protection film on the polished surface; and a second polishing step of polishing the surface of the wafer where the protection film is formed while supplying a finish polishing liquid to a polishing surface of a finish polishing cloth different from the rough polishing cloth.Type: ApplicationFiled: May 13, 2015Publication date: September 7, 2017Applicant: SUMCO CORPORATIONInventors: Kazuaki KOZASA, Katsuhisa SUGIMORI, Syunya KOBUCHI
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Publication number: 20170011903Abstract: A mirror-finishing chamfer polishing is applied using an abrasive-grain-free polishing solution to a chamfered portion of a semiconductor wafer having an oxide film on a top side or the top and bottom sides of the semiconductor wafer and having no oxide film on the chamfered portion. Further, prior to the mirror-finishing chamfer polishing, a pre-finish mirror chamfer polishing is applied using an abrasive-grain-containing polishing solution to the chamfered portion of the semiconductor wafer having the oxide film on the top side or the top and bottom sides and on the chamfered portion.Type: ApplicationFiled: November 19, 2014Publication date: January 12, 2017Applicant: SUMCO CORPORATIONInventors: Kazuaki KOZASA, Syunya KOBUCHI, Katsuhisa SUGIMORI
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Patent number: 9305850Abstract: A method and an apparatus of etching a semiconductor wafer are provided. The etching apparatus of a semiconductor wafer having a marker inside includes: a monitoring device capable of monitoring a surface of the semiconductor wafer so as to detect the marker; a nozzle capable of jetting a mixed gas that contains hydrogen fluoride and ozone onto the surface of the semiconductor wafer; a regulator capable of adjusting at least one of hydrogen fluoride concentration and ozone concentration in the mixed gas; and a controller capable of determining whether the marker is detected by the monitoring device and terminating the etching process.Type: GrantFiled: August 15, 2012Date of Patent: April 5, 2016Assignee: SUMCO TECHXIV CORPORATIONInventors: Kazuaki Kozasa, Tomonori Kawasaki
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Patent number: 8992791Abstract: A silicon wafer surface other than a defect is oxidized by ozone to form a silicon oxide film. A hydrofluoric acid is sprayed and subsequently a cleaning gas is sprayed onto the surface of the silicon wafer.Type: GrantFiled: September 30, 2009Date of Patent: March 31, 2015Assignee: Sumco Techxiv CorporationInventors: Kazuaki Kozasa, Tomonori Kawasaki, Takahisa Sugiman, Hironori Nishimura
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Patent number: 8696809Abstract: A manufacturing method of an epitaxial silicon wafer is provided. The epitaxial silicon wafer includes: a substrate cut out from a silicon monocrystal that has been manufactured, doped with nitrogen and pulled up in accordance with Czochralski method; and an epitaxial layer formed on the substrate. The manufacturing method includes: cleaning a surface of the substrate with fluorinated acid by spraying onto the surface of the substrate fluorinated acid vaporized by a bubbling tank of a substrate cleaning apparatus; and forming an epitaxial layer on the cleaned surface of the substrate.Type: GrantFiled: June 12, 2008Date of Patent: April 15, 2014Assignee: Sumco Techxiv CorporationInventors: Kazuaki Kozasa, Kosuke Miyoshi
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Publication number: 20120305187Abstract: A method and an apparatus of etching a semiconductor wafer are provided. The etching apparatus of a semiconductor wafer having a marker inside includes: a monitoring device capable of monitoring a surface of the semiconductor wafer so as to detect the marker; a nozzle capable of jetting a mixed gas that contains hydrogen fluoride and ozone onto the surface of the semiconductor wafer; a regulator capable of adjusting at least one of hydrogen fluoride concentration and ozone concentration in the mixed gas; and a controller capable of determining whether the marker is detected by the monitoring device and terminating the etching process.Type: ApplicationFiled: August 15, 2012Publication date: December 6, 2012Applicant: SUMCO TECHXIV CORPORATIONInventors: Kazuaki Kozasa, Tomonori Kawasaki
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Patent number: 8303373Abstract: A diluted slurry supplying apparatus utilized in a polishing apparatus for finishing a semiconductor wafer with a slurry containing colloidal silica and water-soluble polymer is provided. The polishing method comprises: a slurry supplier capable of supplying the slurry containing the colloidal silica and the water-soluble polymer; a diluent supplier capable of supplying a diluent containing an aggregation preventing agent to dilute the slurry; a mixer capable of receiving the slurry and the diluent having been supplied from the slurry supplier and the diluent supplier, respectively, the mixer forming a diluted slurry with a pH value of at least 9; and an ultrasonic vibrator capable of applying an ultrasonic vibration to the diluted slurry staying in the mixer or being fed out from the mixer. Here, the diluent supplying apparatus can change a dilution proportion of the diluted slurry.Type: GrantFiled: May 22, 2009Date of Patent: November 6, 2012Assignee: Sumco Techxiv CorporationInventor: Kazuaki Kozasa
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Patent number: 8273260Abstract: A method of etching a semiconductor wafer is provided. The method comprises the steps of: jetting a mixed gas including hydrogen fluoride and ozone onto a surface of a semiconductor wafer; monitoring the surface of the semiconductor wafer; analyzing the surface of the semiconductor wafer; and adjusting at least one of the hydrogen fluoride concentration and the ozone concentration in the mixed gas based on a result of the analysis.Type: GrantFiled: May 13, 2009Date of Patent: September 25, 2012Assignee: Sumco Techxiv CorporationInventors: Kazuaki Kozasa, Tomonori Kawasaki
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Publication number: 20100093177Abstract: A silicon wafer surface other than a defect is oxidized by ozone to form a silicon oxide film. A hydrofluoric acid is sprayed and subsequently a cleaning gas is sprayed onto the surface of the silicon wafer.Type: ApplicationFiled: September 30, 2009Publication date: April 15, 2010Applicant: SUMCO TECHXIV CORPORATIONInventors: Kazuaki KOZASA, Tomonori KAWASAKI, Takahisa SUGIMAN, Hironori NISHIMURA
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Patent number: 7666063Abstract: A rough-polishing method for conducting a rough polishing before mirror-finish polishing on a semiconductor wafer using a polishing apparatus includes a first polishing step for polishing the semiconductor wafer using slurry containing colloidal silica supplied by a slurry supplying unit and a second polishing step for polishing the semiconductor wafer using alkali solution provided by mixing deionized water supplied from a deionized-water supplying unit and alkali concentrate solution supplied by an alkali-concentrate-solution supplying unit. The pH value of the alkali solution and polishing time in the second polishing step are determined based on the load current value of the polishing table in the first polishing step.Type: GrantFiled: October 13, 2008Date of Patent: February 23, 2010Assignee: Sumco Techxiv CorporationInventors: Kazuaki Kozasa, Tomonori Kawasaki, Kosuke Miyoshi
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Publication number: 20090298393Abstract: A diluted slurry supplying apparatus utilized in a polishing apparatus for finishing a semiconductor wafer with a slurry containing colloidal silica and water-soluble polymer is provided. The polishing method comprises: a slurry supplier capable of supplying the slurry containing the colloidal silica and the water-soluble polymer; a diluent supplier capable of supplying a diluent containing an aggregation preventing agent to dilute the slurry; a mixer capable of receiving the slurry and the diluent having been supplied from the slurry supplier and the diluent supplier, respectively, the mixer forming a diluted slurry with a pH value of at least 9; and an ultrasonic vibrator capable of applying an ultrasonic vibration to the diluted slurry staying in the mixer or being fed out from the mixer. Here, the diluent supplying apparatus can change a dilution proportion of the diluted slurry.Type: ApplicationFiled: May 22, 2009Publication date: December 3, 2009Inventor: Kazuaki Kozasa