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:
Dec. 26, 2000
Filed:
May. 04, 1999
Hironobu Kawahara, Kudamatsu, JP;
Yoshinao Kawasaki, Yamaguchi-Ken, JP;
Yoshiaki Sato, Kudamatsu, JP;
Ryooji Fukuyama, Kudamatsu, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A plasma etching method includes the steps of placing a sample having metal a wiring portion on a sample table in a vacuum vessel, evacuating the vacuum vessel to establish a reduced pressure in the vacuum vessel, introducing an etching gas into the vacuum vessel while continuing to evacuate the vacuum vessel to maintain the reduced pressure in the vacuum vessel, and generating a plasma from the etching gas under the reduced pressure in the vacuum vessel using radio-frequency power. The plasma etches the metal wiring portion, and a residue forms on the metal wiring portion during the etching of the metal wiring portion by the plasma. The method further includes the step of applying to the sample table a bias voltage which periodically changes between two different voltages during the etching of the metal wiring portion by the plasma to remove the residue from the metal wiring portion.