Dielectric constant, unit barrier thickness and breakdown voltages of anodic $Al_2O_3$ using 2% ammonium tartrate $((NH_4)_2C_4H_4O_6)$ aqueous solution as an electrolyte are measured and problems in the application of aluminum anodization method to the I.C. fabrication are studied experimentally.
Low breakdown voltages of the formed $Al_2O_3$ layer have been found to be mainly due to non-ideal, sharp and rough surfaces in the metal pattern edge.
The breakdown voltage can be improved by long anodization time of about two hours or by 'anodize and $Al_2O_3$ etch before anodization' method.