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:
Nov. 26, 1996
Filed:
May. 24, 1995
Takatoshi Hirota, Kawasaki, JP;
Fujitsu Limited, Kanagawa, JP;
Abstract
The method to etch an electrically conductive film comprises the steps of: forming a metal conductor film comprising copper or copper alloy, upon a substrate; and forming a mask pattern upon the metal conductor film; and etching an exposed part of the metal conductor film by the use of the mask pattern and a reactive ion-etching (RIE) employing a plasma of a gas mixture comprising a silicon tetra-chloride (SiCl.sub.4) gas, a nitrogen (N.sub.2) gas and a carbon compound gas, so that the exposed part of the metal conductor film is removed so as to leave the masked part. The metal conductor film may further comprise a diffusion protection layer formed of a refractory metal or its alloy upon and/or underneath the copper/mainly-copper layer. The mask pattern may be typically formed of silicon dioxide (SiO.sub.2). The substrate may further comprise an insulating layer thereon, typically formed of silicon dioxide (SiO.sub.2), for contacting said metal conductor film. The carbon compound gas may typically be a carbon tetra-chloride (CCl.sub.4), methane (CH.sub.4), ethane (C.sub.2 H.sub.6) or propane (C.sub.3 H.sub.8) and so on. When SiCl.sub.4 is employed the content may typically be 6.6 to 15% by volume in the gas mixture. When methane (CH.sub.4) gas is employed the content may typically be 8 to 18% by volume in the gas mixture. The etching step may preferably performed at a substrate temperature higher than 250.degree. C.