MOCVD of advanced dielectric and ferroelectric films by liquid delivery

Abstract An MOCVD technique has been developed for (Ba,Sr)TiO3 (BST) films based on flash vaporization of metalorganic precursors with exceptional composition control and no process drift for the equivalent of ∼1300 wafers of 30 nm thickness. Charge storage density of > 60 fF/μm2 has been routinely obtained for 30 nm films and values up to 100 fF/μm2 have been observed for films with electrical leakage < 10−7 A/cm2. The method has also been applied to other materials systems, including Pb(Zr,Ti)O3 (PZT). High quality, single phase PZT films have been deposited and the effect of Zr/Ti ratio has been examined. Remanent polarization (Pr) and coercive field follow expected trends. Pr of ∼ 20 μC/cm2 was observed with fully saturated hysteresis at 3V for films with 140–175 nm thickness. Coercive voltages < 1 V have also been obtained. This finding demonstrates promise of this deposition method for low voltage applications.