Corrosion-resistant aluminum article for semiconductor processing equipment

摘要

Corrosion of an aluminum article exposed to corrosive halogen-containing species within semiconductor processing apparatus is avoided by fabricating the aluminum article from a high purity aluminum-magnesium alloy having a magnesium content of about 0.1% to 1.5% by weight, either throughout the entire article or at least in the surface region which is to be rendered corrosion-resistant, and a mobile impurity atom content of less than 0.2% by weight. Upon exposure of the article to a halogen-containing species, a protective magnesium halide layer is formed beneath the surface of the article. The protective layer prevents halogens from penetrating to the base aluminum, thereby protecting the article from corrosion and cracking. To protect the magnesium layer from abrasion, the article preferably also includes a hard, cohesive coating over the magnesium halide layer. A preferred cohesive coating is aluminum oxide or aluminum nitride.