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. 25, 1997
Filed:
Aug. 15, 1995
Akihiko Isao, Chichibu, JP;
Susumu Kawada, Chichibu, JP;
Atsushi Hayashi, Chichibu, JP;
Nobuyuki Yoshioka, Itami, JP;
Kazuyuki Maetoko, Itami, JP;
Ulvac Coating Corporation, Chichibu, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
A phase-shifting photomask blank has a transparent substrate, a phase-shifting film deposited on the transparent substrate, the phase-shifting film including a transversely central composition which results in a reduced rate of side etching, and a patterned photoresist film masking the phase-shifting film. When the phase-shifting film is dry-etched through the patterned photoresist film into a desired circuit pattern, transversely different rates of side etching of the phase-shifting film are substantially equalized due to the reduced rate of side etching resulting from the transversely central composition. The circuit pattern includes openings defined by removal of the phase-shifting film and shifters left between the openings. The shifters have respective side surfaces free of steps and extending substantially perpendicularly from the transparent substrate. If the phase-shifting film comprises a film of molybdenum silicide oxide nitride deposited by sputtering, then the proportion of a nitrogen mono oxide gas in a sputtering gas is adjusted to control the transversely central composition of the phase-shifting film.