Controlled oxidation of tantalum and aluminium in a radio-frequency-excited glow discharge

Abstract

A controlled method of oxidizing thin films of tantalum and aluminium in a radio-frequency-excited glow discharge is described. The oxide films have been assessed as the dielectric in metal-metal-oxide-metal capacitor structures. Reciprocal capacitance varies linearly with the voltage applied to the metal film in the discharge over the range 0 to 48 v. The process is similar to but less efficient than anodization in a liquid electrolyte. Compared with oxide films formed by liquid anodization the electrical properties are poor, probably because of the more energetic conditions in the discharge.