COATING FILM EXCELLENT IN CORROSION RESISTANCES TO HALOGEN GAS AND HALOGEN PLASMA, AND LAMINATED STRUCTURE FORMED WITH THE COATING FILM

摘要

PROBLEM TO BE SOLVED: To provide a coating film constitution which exhibits excellent corrosion resistance to plasma by specifying the atomic ratio of O/Al and specifying the half-width in X-ray diffraction. SOLUTION: This coating film is composed of the oxide of Al. The atm. ratio of O/Al of the thin film layer is >=1.3 to <1.5 and the thin film layer has no peak below the half-width 5 deg. in X-ray diffraction. The stipulation relating to the atomic ratio signifies a slight oxygen lacking state resulted by the stoichiometric ratio (O/Al=3/2=1.5) of Al2 O3 . The term, 'the thin film layer has no peak below the half-width 5 deg.' signifies that the Al oxide is amorphous. The thickness of the coating film is preferably 0.1 to 20μm. The formation of the thin film layer by a sputtering method on an arbitrary base material is an optimum method as an example of the process for production. As a result, the excellent halogen gas corrosion resistance and plasma corrosion resistance is exhibited always stably.