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:
Oct. 29, 2002
Filed:
Aug. 16, 1999
Haruhiro Harry Goto, Saratoga, CA (US);
Kai-An Wang, Cupertino, CA (US);
Jenny T. Tran, San Jose, CA (US);
Applied Komatsu Technology, Inc., Tokyo, JP;
Abstract
A process and apparatus for etching an exposed region of a multi-layer metal having at least two layers: a layer of aluminum or aluminum alloy, and an underlying layer of refractory metal. The etching process includes at least two steps. In a first step, the aluminum layer is etched by processing the substrate with a first plasma chemistry that etches aluminum. Optionally a portion, but not all, of the refractory metal layer also is etched by the first plasma chemistry. In a subsequent second step, the remainder of the refractory metal layer is etched by a second plasma chemistry that etches the lower refractory metal much faster than it etches aluminum. The invention minimizes undercutting of the aluminum side wall as the refractory metal layer becomes depleted.