Apparatus for coating or etching by means of a plasma
AssigneeLeybold Aktiengesellschaft
InventorHeinrich Grunwald
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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.
Claims15
Apparatus for plasma coating or etching, with a first electrode in electrical connection with the substrate to be coated or etched, as well as a second electrode arranged above the first electrode, the two electrodes being disposed within a process chamber serving as a third electrode, and wherein the first electrode is connected with a medium frequency generator that controls the current and the ion bombardment of the substrate, while the second electrode is connected with a high frequency generator that controls the extent of dissociation and the formation of radical species, characterised in that the current of the ionic bombardment is also controllable with a fixedly predetermined voltage of the medium frequency generator (15).
Dependencies are inferred from the claim text.