depositing a ferroelectric layer over a substrate;

performing a first ionized physical deposition process to deposit a top electrode layer over and in contact with the ferroelectric layer, wherein the first ionized physical deposition process is performed with an AC bias in a range from about 0 W to about 50 W, and the AC bias does not exceed 50 W to prevent a ratio of non-ferro phase in the ferroelectric layer from increasing, wherein the ferroelectric layer is exposed to ionized metal atoms during the first ionized physical deposition process;

patterning the top electrode layer into a top electrode; and

patterning the ferroelectric layer into a ferroelectric element below the top electrode.