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. 16, 1990
Filed:
May. 19, 1989
Masaaki Sato, Kanagawa, JP;
Yoshinobu Arita, Kanagawa, JP;
Nippon Telegraph and Telephone Corporation, Tokyo, JP;
Abstract
A plasma etching apparatus a first cathode electrode, an anode electrode, an annular second cathode electrode, a magnetic field applying unit and high-frequency power sources. An object to be etched is placed on the first cathode electrode. The anode electrode is arranged opposite to the first cathode electrode so as to be separated therefrom and connected to a constant potential source. The second cathode electrode is located between the first cathode electrode and the anode electrode and substantially surrounds the first cathode electrode in an insulated state. The magnetic field applying unit includes coils which generate lines of magnetic force passing through the annular second cathode electrode substantially parallel to a surface of the first cathode electrode on which the object to be etched is placed. The high-frequency power sources are respectively connected to the first and second cathode electrodes to generate a plasma by gas discharge, thereby generating ions near the first and second cathode electrodes.