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. 30, 1993
Filed:
Sep. 20, 1991
Yasunori Ohno, Mito, JP;
Takashi Iga, Hitachi, JP;
Noriyuki Sakudo, Hitachi, JP;
Kenichi Natsui, Hitachi, JP;
Isao Hashimoto, Hitachi, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A plasma-generating apparatus has a plasma discharge chamber having a plasma-generation region. Microwave energy is applied, while introducing plasma-forming gas, and a magnetic field is applied to the plasma-generation region by an electromagnetic coil extending around the chamber. To enhance the field in the plasma-generation region while reducing it outside said region, and a permanent magnet arrangement is at least partly located radially within the coil so as to provide a unidirectional magnetic field which extends through the whole of the plasma-generation region as seen in radial cross-section and is oriented in the axial direction of the coil.