Simultaneous addition of Al and N to Ta-O thin films is found to significantly improve the dielectric properties of the films. Specifically, substitution of 10-40 at. % Al for Ta along with ∼2 at. % N for O is found to decrease the density of catastrophic defects in the films, resulting in high and statistically more uniform breakdown voltages. This conclusion is based on evaluation of ∼750 individual capacitors in each experiment.