Edge detection method for transparent substrate by detecting non-light-emitting region of transparent substrate

US8339615B2 · kind B2 · utility

Assignee

• Kabushiki Kaisha Toshiba · JP

Inventors

• Masayuki Dohi · Yokohama, JP
• Itsuko Sakai · Chiryu, JP
• Takayuki Sakai · Nomi, JP
• Shunji Kikuchi · Kitakami, JP
• Takuto Inoue · Kitakami, JP
• Akihiro Hori · Ooita, JP
• Masayuki Narita · Wako, JP

Key dates

• Filing date: Jul 28, 2009
• Grant date: Dec 25, 2012
• Expiry date: Dec 13, 2030

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01L21/67259
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

An edge detection method includes preparing a transparent substrate which includes a first main face having a first main region and a first peripheral region and a second main face having a second main region and a second peripheral region, the first peripheral region having an inclination angle of θa1 and the second peripheral region having an inclination angle of θa2, causing measuring light to enter the first peripheral region from a direction perpendicular to the first main region, detecting a non-emitting region where the measuring light is not emitted from the second peripheral region, and detecting an edge of the transparent substrate on the basis of the non-emitting region, wherein if a refractive index of the transparent substrate is n, the inclination angles θa1 and θa2satisfy the following expression:n×sin(θa1+θa2−arcsin(sin θa1/n))≧1.