Water vapor passivation of a wall facing a plasma
AssigneeApplied Materials, Inc.
InventorXinyu Fu
Life of this patent
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Abstract
A chamber passivation method particularly useful for hydrogen plasma cleaning of low-k dielectrics prior to coating a barrier layer into a via hole with hydrogen radicals are provided from a remote plasma source. For each wafer, the chamber is passivated with water vapor (or other gas even more chemabsorbed on plasma facing walls) passed through the remote plasma source prior to the ignition of the hydrogen plasma. The water vapor is absorbed on walls, such as alumina and quartz parts of the remote plasma source, and forms a protective mono-layer that endures sufficiently long to protect the walls during the generation of the hydrogen plasma. Thereby, the plasma facing walls, particularly of a dielectric such as alumina, are protected from etching.
Claims22
A passivation method for processing a substrate in a plasma processing chamber, comprising the steps of:
- injecting a passivating gas in a non-excited state into the processing chamber, wherein the passivating gas is at least as greatly chemabsorbed on walls of the processing chamber as is water vapor;
- and
- then processing the substrate in the processing chamber in a plasma of a processing gas.
A plasma processing method, comprising the steps performed for each of a plurality of serially processed substrate of:
- inserting a substrate into a plasma processing chamber including a pedestal for supporting the substrate, a gas showerhead opposed to the pedestal, and a remote plasma source having a supply tube connecting its output to a manifold in back of the showerhead;
- passing water vapor through the remote plasma source without exciting the water vapor into an effective plasma;
- then passing a reducing processing gas though the remote plasma source and exciting it into a plasma;
- and
- then extinguishing the plasma and removing the substrate from the plasma processing chamber.
A passivation and processing method, comprising the steps of:
- injecting unexcited water vapor into a vacuum processing chamber containing a substrate to be processed;
- then pumping the vacuum processing chamber to remove a substantial amount of the water vapor therefrom;
- and
- thereafter exciting a processing gas into a plasma for processing the substrate within the vacuum processing chamber.
A method of operating a hydrogen plasma source, comprising repeating a sequence of the steps of:
- a first step of passing water vapor through a plasma generator while the generator is not activated;
- and
- a second step of passing hydrogen gas through the plasma generator while the generator is activated.
Dependencies are inferred from the claim text.