In this article, the properties of plasma deposited Al2O3 and Ta2O5 thin films (k ≈ 12 and 25 respectively) are discussed as possible high k alternatives to SiO2. The films were formed in a 4” compatible triode plasma CVD reactor using Ta(V)ethoxide for Ta2O5 and Al acetylacetonate, Al tri-sec-butoxide, Al triisopropoxide, and triethyldialuminum tri-sec-butoxide metal organic precursors for Al2O3. Precursors were heated to 150 °C and delivered to the reactor with He and Ar carrier gases downstream from the plasma. For Ta2O5 films, film properties were strongly dependent on the oxygen precursor, with O2 resulting in higher growth rates, better uniformity, and better stability to water exposure than films deposited using N2O. For Al2O3, distinct differences in OH and C incorporation were observed for the various Al and O precursors studied. In particular, films deposited from alkoxides had higher concentrations of OH and C, and had higher leakage currents. For films deposited with triethydialuminum tri-sec-butoxide, the N2O plasma O atom source resulted in smaller leakage currents and less C than an O2 plasma. Temperature dependence of the deposition rates and the leakage currents was also observed.