Improvement of barrier anodic oxide Al2O3 passivation of aluminum alloy for LSI/FPD plasma process equipment

Barrier type anodic oxides film of the aluminum alloy in nonaqueous electrolyte solution has some excellent characteristics as a passivation film. In electrolyte that used the ethylene glycol as nonaqueous solution, the thickness of the anodic oxides film was able to be formed only up to about 0.3μm. However, the thickness of 0.5μm or more is demanded from the viewpoint of mechanical strength in actual manufacturing equipments. The barrier type anodic oxides film that exceeded 0.5μm was able to be formed by the use of a low dielectric constant glycol system solvent, the viscosity control of the electrolyte and other optimizations. The thick nonaqueous anodic oxides will be put to actual use as the passivation film for the plasma process equipment of the LSI/FPD manufacturing.