The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 10, 1998
Filed:
Oct. 30, 1996
Sony Corporation, Tokyo, JP;
Abstract
An optical disk master exposure apparatus employs first laser light modulated in accordance with signals to be recorded is irradiated on a resist layer to expose the resist layer in patterns corresponding to the signals to be recorded, and second laser light having a wavelength which is not sensed by the resist layer is irradiated on a predetermined surface of a predetermined member. The thickness of the resist layer is measured based on a change in output amount of the second laser light emitted by a light source, the output light amount of which is controlled so as to maintain a constant amount of second reflected light produced by irradiating the second laser light on the predetermined surface of the predetermined member. Also, the predetermined surface of the predetermined member is tested for possible defects existing thereon based on a change in amount of the second reflected light. In this way, a layer thickness test and a defect test can be conducted during an exposure stage, thereby making it possible to integrate the layer thickness testing stage, the defect testing stage, and the exposure stage into a single stage and accordingly realize an exposure apparatus which is capable of simply performing a mastering procedure at a low cost.