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:
Sep. 05, 1989
Filed:
Jul. 01, 1988
Heinrich Grunwald, Hanau, DE;
Leybold Aktiengesellschaft, Hanau, DE;
Abstract
The invention concerns apparatus for coating or etching by means of a plasma. Herein a first electrode (5) is connected to a high frequency voltage which produces plasma from a gas. A second electrode (6), on which the substrate (7) to be coated or etched is disposed, is connected to a medium frequency voltage which accelerates the ions of the plasma to the substrate (7). According to the invention, this medium frequency voltage consists of unipolar pulses that have the same amplitude for a predeterminable time interval. The number of ions impinging on the substrate (7) is thereby decoupled from the amplitude of the applied medium frequency voltage. It is determined solely by the frequency or width of these pulses.