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:
Apr. 19, 2005
Filed:
Mar. 28, 2002
Satoshi Aoyama, Hyogo-ken, JP;
Shouichi Sakamoto, Hyogo-ken, JP;
Takaei Sasaki, Saitama-ken, JP;
Noriyuki Harashima, Saitama-ken, JP;
Satoshi Aoyama, Hyogo-ken, JP;
Shouichi Sakamoto, Hyogo-ken, JP;
Takaei Sasaki, Saitama-ken, JP;
Noriyuki Harashima, Saitama-ken, JP;
Ulvac Coating Corporation, Chichibu, JP;
Mitsubishi Denki Kabushiki, Tokyo, JP;
Abstract
A dry-etching method comprises the step of dry-etching a metal thin film as a chromium-containing film, wherein the method is characterized by using, as an etching gas, a mixed gas including (a) a reactive ion etching gas, which contains an oxygen-containing gas and a halogen-containing gas, and (b) a reducing gas added to the gas component (a), in the process for dry-etching the metal thin film. The dry-etching method permits the production of a photomask by forming patterns to be transferred to a wafer on a photomask blank. The photomask can in turn be used for manufacturing semiconductor circuits. The method permits the decrease of the dimensional difference due to the coexistence of coarse and dense patterns in a plane and the production of a high precision pattern-etched product.