A processing chamber may be effectively cleaned by a remote plasma flowed through
the chamber in a direction opposite to the direction of gas flowed during wafer
processing. Specifically, the remotely generated plasma may be introduced directly
into the chamber through a processing gas exhaust or other port, and then be exhausted
from the chamber by traveling through the gas distribution shower head to the foreline.
In one embodiment of the present invention, this reverse flow of remote cleaning
plasma is maintained for the duration of the chamber cleaning step. In an alternative
embodiment, the direction of flow of the remote cleaning plasma through the chamber
is alternated between this reverse flow and a conventional forward flow.