Patents by Inventor Naohisa Tamada
Naohisa Tamada 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: 11018004Abstract: A method of manufacturing a semiconductor device according to the present invention includes a step of forming an opening portion in a resist coated on a substrate, a step of coating a thermally-shrinking shrink agent on the resist to fill the opening portion with the shrink agent, a shrinking step of heating and thermally shrinking the shrink agent to reduce a width of the opening portion, a removing step of removing the shrink agent after the shrinking step, a step of forming a metal layer on the resist and in the opening portion after the removing step and a step of removing a portion of the metal layer above the resist and the resist, wherein in the shrinking step, a side surface of the resist forming the opening portion forms a curved surface protruding toward a center portion of the opening portion.Type: GrantFiled: June 1, 2017Date of Patent: May 25, 2021Assignee: Mitsubishi Electric CorporationInventors: Takahiro Ueno, Naohisa Tamada, Motoshi Kitagawa
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Publication number: 20200043717Abstract: A method of manufacturing a semiconductor device according to the present invention includes a step of forming an opening portion in a resist coated on a substrate, a step of coating a thermally-shrinking shrink agent on the resist to fill the opening portion with the shrink agent, a shrinking step of heating and thermally shrinking the shrink agent to reduce a width of the opening portion, a removing step of removing the shrink agent after the shrinking step, a step of forming a metal layer on the resist and in the opening portion after the removing step and a step of removing a portion of the metal layer above the resist and the resist, wherein in the shrinking step, a side surface of the resist forming the opening portion forms a curved surface protruding toward a center portion of the opening portion.Type: ApplicationFiled: June 1, 2017Publication date: February 6, 2020Applicant: Mitsubishi Electric CorporationInventors: Takahiro UENO, Naohisa TAMADA, Motoshi KITAGAWA
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Patent number: 9711936Abstract: A method for manufacturing a semiconductor laser of the present invention includes a step of forming an insulating film on a surface of a grooved semiconductor substrate, a step of pasting an insulating sheet to a top surface of the insulating film so as to cover an opening of the groove and forming an insulating layer on the semiconductor substrate, a step of forming an opening of providing a first opening in the insulating layer so that a part corresponding to an electrode of the semiconductor substrate is exposed and a step of forming the electrode on a top surface of the insulating layer so as to fill the first opening.Type: GrantFiled: July 25, 2016Date of Patent: July 18, 2017Assignee: Mitsubishi Electric CorporationInventors: Masafumi Minami, Naohisa Tamada, Takahiro Ueno, Motoshi Kitagawa
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Publication number: 20170133820Abstract: A method for manufacturing a semiconductor laser of the present invention includes a step of forming an insulating film on a surface of a grooved semiconductor substrate, a step of pasting an insulating sheet to a top surface of the insulating film so as to cover an opening of the groove and forming an insulating layer on the semiconductor substrate, a step of forming an opening of providing a first opening in the insulating layer so that a part corresponding to an electrode of the semiconductor substrate is exposed and a step of forming the electrode on a top surface of the insulating layer so as to fill the first opening.Type: ApplicationFiled: July 25, 2016Publication date: May 11, 2017Applicant: Mitsubishi Electric CorporationInventors: Masafumi MINAMI, Naohisa TAMADA, Takahiro UENO, Motoshi KITAGAWA
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Patent number: 6890692Abstract: A photomask for focus monitoring of the present invention is provided with a substrate that allows the exposure light to pass through and a unit mask structure for focus monitoring. Unit mask structure for focus monitoring has two patterns, and that are formed on the surface of substrate and a light blocking film that has a rear surface pattern that is formed on the rear surface of substrate for substantially differentiating the incident directions of the exposure light that enters two patterns, and for position measurement. When the dimension of rear surface pattern is L and the wavelength of the exposure light is ?, L/? is 10, or greater.Type: GrantFiled: June 4, 2004Date of Patent: May 10, 2005Assignee: Renesas Technology Corp.Inventors: Shuji Nakao, Yuki Miyamoto, Naohisa Tamada, Shinroku Maejima
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Publication number: 20050064676Abstract: In a first step, first trenches are formed to constitute alignment marks. In a second step, second trenches are formed, and the first and second trenches are filled with metal. When detecting alignment marks, the second trenches filled with metal prevent the position of the first trenches from being detected. In a third step, third trenches of the same shape as the first trenches are formed. In a fourth step, fourth trenches are formed, and the third and fourth trenches are filled with metal. When detecting alignment marks, the fourth trenches filled with metal prevent the position of the third trenches formed in a lower layer from being detected. The third and fourth steps are repeated with an increase in the number of stacked layers. Consequently, influences caused by detection of alignment marks formed in a lower layer are reduced while controlling an increase in the area occupied by alignment marks.Type: ApplicationFiled: September 21, 2004Publication date: March 24, 2005Inventors: Akihiro Tobioka, Naohisa Tamada
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Patent number: 6869735Abstract: In the layout of a photomask for pattern transfer, main patterns for transferring an image to a photosensitive film are positioned; auxiliary patterns, which do not substantially transfer an image to a photosensitive film are temporarily positioned; an auxiliary pattern is selected so an end partially overlaps an end of the main pattern and makes contact with the main pattern; and adjusting the position of the auxiliary pattern selected so that the end of the auxiliary pattern selected completely overlaps the end of the main pattern. Inspection of the photomask for mask defects is simplified while achieving an increase in resolution of a photomask for pattern transfer.Type: GrantFiled: January 8, 2003Date of Patent: March 22, 2005Assignee: Renesas Technology Corp.Inventor: Naohisa Tamada
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Publication number: 20040219441Abstract: A photomask for focus monitoring of the present invention is provided with a substrate that allows the exposure light to pass through and a unit mask structure for focus monitoring. Unit mask structure for focus monitoring has two patterns, and that are formed on the surface of substrate and a light blocking film that has a rear surface pattern that is formed on the rear surface of substrate for substantially differentiating the incident directions of the exposure light that enters two patterns, and for position measurement. When the dimension of rear surface pattern is L and the wavelength of the exposure light is &lgr;, L/&lgr; is 10, or greater.Type: ApplicationFiled: June 4, 2004Publication date: November 4, 2004Applicant: RENESAS TECHNOLOGY CORP.Inventors: Shuji Nakao, Yuki Miyamoto, Naohisa Tamada, Shinroku Maejima
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Patent number: 6797443Abstract: Non-telecentric illuminating light obtained by controlling the shape of an opening of an illumination aperture is directed onto a photomask, and a characteristic such that an image of a pattern of the photomask formed by the non-telecentric illumination moves in the direction perpendicular to an optical axis when an image-forming plane is moved in the direction of the optical axis, to perform focus monitoring. This eliminates the need for a special photomask, so that inexpensive and highly precise focus monitoring method, focus monitoring apparatus, and a method of manufacturing a semiconductor device can be obtained.Type: GrantFiled: November 7, 2001Date of Patent: September 28, 2004Assignee: Renesas Technology Corp.Inventors: Shuji Nakao, Yuki Miyamoto, Naohisa Tamada
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Patent number: 6764794Abstract: A photomask for focus monitoring of the present invention is provided with a substrate that allows the exposure light to pass through and a unit mask structure for focus monitoring. Unit mask structure for focus monitoring has two patterns, and that are formed on the surface of substrate and a light blocking film that has a rear surface pattern that is formed on the rear surface of substrate for substantially differentiating the incident directions of the exposure light that enters two patterns, and for position measurement. When the dimension of rear surface pattern is L and the wavelength of the exposure light is &lgr;, L/&lgr; is 10, or greater.Type: GrantFiled: April 4, 2002Date of Patent: July 20, 2004Assignee: Renesas Technology Corp.Inventors: Shuji Nakao, Yuki Miyamoto, Naohisa Tamada, Shinroku Maejima
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Publication number: 20040018434Abstract: A method for the layout of a photomask for pattern transfer according to the present invention is provided with the step of positioning main patterns for transferring an image to a photosensitive film; the step of temporarily positioning auxiliary patterns, which do not substantially transfer an image to a photosensitive film; the step of selecting an auxiliary pattern, of which an end side forming one end thereof partially overlaps an end side forming one end of the main pattern so as to make contact; and the step of adjusting the position of the selected auxiliary pattern so that the end side of the selected auxiliary pattern completely overlaps the end side of the main pattern so as to make contact. It becomes possible to easily carry out inspection for mask defects while achieving an increase in resolution by using such a method for layout of a photomask for pattern transfer.Type: ApplicationFiled: January 8, 2003Publication date: January 29, 2004Applicant: Mitsubishi Denki Kabushiki KaishaInventor: Naohisa Tamada
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Publication number: 20030203286Abstract: The high-transmittance halftone phase shift mask is structured, in a first phase shift pattern region, with a transmission region exposing a transparent substrate and having a rectangular (square) two-dimensional shape; a phase shift region surrounding the transmissive region exposing halftone phase shift film and having a rectangular shape two-dimensional shape; and a light shielding region surrounding the phase shift region and formed of a light shielding film provided on the halftone phase shift film. With the present mask, a high-transmittance halftone phase shift mask that can transfer desired pattern clearly on the photosensitive resin and a method for producing semiconductor devices using the mask can be attained.Type: ApplicationFiled: October 29, 2002Publication date: October 30, 2003Applicant: MITSUBISHI DENKI KABUSHIKI KAISHAInventors: Kiyoshi Maeshima, Naohisa Tamada
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Publication number: 20030073009Abstract: A photomask for focus monitoring of the present invention is provided with a substrate that allows the exposure light to pass through and a unit mask structure for focus monitoring. Unit mask structure for focus monitoring has two patterns, and that are formed on the surface of substrate and a light blocking film that has a rear surface pattern that is formed on the rear surface of substrate for substantially differentiating the incident directions of the exposure light that enters two patterns, and for position measurement. When the dimension of rear surface pattern is L and the wavelength of the exposure light is &lgr;, L/&lgr; is 10, or greater.Type: ApplicationFiled: April 4, 2002Publication date: April 17, 2003Applicant: Mitsubishi Denki Kabushiki KaishaInventors: Shuji Nakao, Yuki Miyamoto, Naohisa Tamada, Shinroku Maejima
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Patent number: 6503665Abstract: A shading member is mounted on the upper side of a corner portion of a shading zone area corresponding to an area causing triple exposure with an adhesive. It is possible to provide a phase shift mask capable of readily exposing a semiconductor substrate with no bad influence on adjacent exposed areas.Type: GrantFiled: October 28, 1999Date of Patent: January 7, 2003Assignee: Mitsubishi Denki Kabushiki KaishaInventor: Naohisa Tamada
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Publication number: 20020195539Abstract: Non-telecentric illuminating light obtained by controlling the shape of an opening of an illumination aperture is directed onto a photomask, and a characteristic such that an image of a pattern of the photomask formed by the non-telecentric illumination moves in the direction perpendicular to an optical axis when an image-forming plane is moved in the direction of the optical axis, to perform focus monitoring. This eliminates the need for a special photomask, so that inexpensive and highly precise focus monitoring method, focus monitoring apparatus, and a method of manufacturing a semiconductor device can be obtained.Type: ApplicationFiled: November 7, 2001Publication date: December 26, 2002Applicant: Mitsubishi Denki Kabushiki KaishaInventors: Shuji Nakao, Yuki Miyamoto, Naohisa Tamada
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Patent number: 6395456Abstract: A semiconductor device achieving higher integration without deterioration of electrical characteristics thereof, a method of manufacturing the semiconductor device, and a method of forming a resist pattern used for that can be obtained. According to the method of forming a resist pattern used for the method of manufacturing a semiconductor device, light is directed via a mask onto a resist film surface formed on a substrate to project a first optical image having a width equal to or less than the wavelength of the light onto the resist surface. The mask is shifted relative to the substrate. Via the shifted mask, light is directed onto the resist film surface to project a second optical image having a width equal to or less than the wavelength of the light onto the resist surface such that the second optical image partially overlaps faith a region where the first optical image is projected.Type: GrantFiled: June 29, 1999Date of Patent: May 28, 2002Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Naohisa Tamada, Yoshiaki Yamada
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Patent number: 5868560Abstract: A reticle that allows deviation in rotation and magnification of an exposure region detected just using a wafer subjected to exposure and development without having to provide an underlying pattern, a pattern transferred using such a reticle, and a correction method are achieved. A first measurement pattern is provided on a dicing line pattern of the X axis direction. Also, a second measurement pattern is formed on a line of extension of the first measurement pattern in the Y axis direction. Similarly, a third measurement pattern is formed on the dicing line pattern in the Y axis direction. A fourth measurement pattern is provided corresponding to the third measurement pattern.Type: GrantFiled: September 30, 1997Date of Patent: February 9, 1999Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Naohisa Tamada, Toshihide Kawachi, Yuki Miyamoto