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:
Jul. 21, 1998
Filed:
Apr. 10, 1996
Hideyuki Shoji, Tokyo, JP;
NEC Corporation, , JP;
Abstract
A method is for dry etching metal films having a high melting point, such as tungsten (W) films. A SiO.sub.2 film is grown on a silicon substrate after which a W film is deposited using sputtering technology. Then, a photoresist film is deposited and is patterned by optical lithography. A semiconductor substrate thus formed is placed in a dry etching system of a narrow gap type with an anode coupled configuration and is etched using a gas mixture composed of SF.sub.6, Cl.sub.2 and O.sub.2 under conditions such that the flow rate ratio of the gases SF.sub.6 /Cl.sub.2 /O.sub.2 are 20.0:0.5.about.1.5:3.about.7. With this, it is possible to achieve excellent selective etching of the W film with respect to the SiO.sub.2 film that is used as an underlying film.