Method of removing material from a surface in a vacuum chamber
AssigneeBalzers Aktiengesellschaft
InventorsJurgen Ramm, Eugen Beck, Albert Zueger
Life of this patent
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Abstract
In order to remove material from the surfaces in a vacuum chamber it is proposed to activate hydrogen gas in a plasma with the aid of a low voltage arc discharge which is supported by a hot emitting electrode in a cathode chamber. The removing method allows the cleaning of surfaces onto which subsequently safely adhering layers of a highest purity can be precipitated. The method can also be used for cleaning vacuum chambers. The small expenditures regarding apparatuses with the high rates of removal to be obtained produce a highly economical practicing of the method.
Claims14
A method of removing material from a surface in a vacuum chamber, comprising:
- admitting inert gas into a contaminant-free cathode chamber for use in striking a low-voltage arc;
- striking a low-voltage arc for generating a plasma in the contaminant-free cathode chamber, using a hot emitting electrode in the cathode chamber, the cathode chamber communicating with the vacuum chamber and the plasma extending into the vacuum chamber;
- supplying hydrogen gas into at least one of the vacuum chamber and the cathode chamber so that hydrogen is provided in the vacuum chamber;
- and
- plasma-activating the hydrogen in the vacuum chamber using the low voltage arc and plasma from the cathode chamber, to remove material from a surface in the vacuum chamber.
An apparatus for removing material from a surface in a vacuum chamber, comprising:
- vacuum pumping means connected to the vacuum chamber for removing gas from the vacuum chamber;
- means defining a cathode chamber having an opening communicating with the vacuum chamber;
- a built-in thermo-emitting electrode in the cathode chamber;
- first gas inlet means for supplying an inert gas to the cathode chamber;
- a first power supply connected to the emitting electrode for heating the emitting electrode to emitting temperatures;
- a second power supply connected to the cathode chamber and to the emitting electrode for producing a low-voltage arc discharge and plasma in the cathode chamber, the second power supply having a polarity so that the plasma in the low-voltage arc extends into the vacuum chamber through the opening;
- and
- at least one second gas inlet means for supplying hydrogen into at least one of the cathode chamber and vacuum chamber so that hydrogen is provided in the vacuum chamber, and so that activation of said second power supply produces the low-voltage arc discharge in the cathode chamber, with plasma which extends to the vacuum chamber forming plasma-activated hydrogen in the vacuum chamber for removing material from a surface of the vacuum chamber.
Dependencies are inferred from the claim text.