abstract |
A process is described for inhibiting the vaporization or sublimation of aluminum base alloy surfaces when exposed to temperatures in excess of 400° C. in a vacuum chamber used for the processing of semiconductor wafers. The process comprises treating such aluminum base alloy surfaces with a plasma comprising a nitrogen-containing gas selected from the group consisting of nitrogen and ammonia. When nitrogen gas is used, the plasma must also contain hydrogen gas. When the vacuum chamber being treated is intended to be used for the deposition of tungsten, the maximum flow of the nitrogen-containing gas into the chamber for the initial 10 seconds of the treatment process must be controlled to avoid impairment of the subsequent tungsten depositions in the chamber. After the treatment step, the cleaned and treated aluminum surface is preferably passivated with nitrogen (N 2 ) gas. |