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:
Sep. 30, 2003
Filed:
May. 17, 2001
Haruo Kokubo, Tokyo-to, JP;
Dai Nippon Printing Co., Ltd., Tokyo-to, JP;
Abstract
In a method of manufacturing a phase-shift photomask comprising the steps of preparing a substrate transparent to an exposure light having a wavelength &lgr; and having a refraction factor n, forming, on the substrate, a pattern including a light-blocking portion blocking the light entering and a light transmission portion transmitting light, and etching the substrate on the transmission portion including a plurality of transmission sections so as to provide adjacent transmission sections, one having a recessed depth d1 and the other one having a recessed depth d2 so as to satisfy an equation of (d1−d2)=&lgr;/2(n−1), the etching step comprises a first etching process of a selective dry-etching to the light transmission section of the substrate having the depth d1 so as to provide a predetermined depth D1 after the formation of the light-blocking portion, a second etching process of a wet-etching process to the transmission section having the depth d1 so as to provide a depth of &lgr;/2(n−1), and a third etching process of a wet-etching to all the light transmission section having the depth d1 and the depth d2 so as to satisfy an equation of (d1−d2)=&lgr;/2(n−1).