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:
Feb. 01, 2000
Filed:
Feb. 25, 1999
Yoshihiko Okamoto, Kodaira, JP;
Tsuneo Terasawa, Ome, JP;
Akira Imai, Hachioji, JP;
Norio Hasegawa, Hinode-machi, JP;
Shinji Okazaki, Urawa, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
To prevent positional shifts of the image forming plane during the exposure process using the two-layer phase shift mask, the height position of the semiconductor wafer 14 is moved in the optical axis direction according to the mask substrate thickness of the second component mask 12b, prior to performing the exposure process which uses the stacked-layer mask 12 that comprises a first component mask 12a formed with a pattern of light-shielding areas and light-transmitting areas and a second component mask 12b formed with a phase shift pattern to produce a phase shift in the transmitted light.