Liquid delivery CVD of PLZT thick films for electro-optic applications

PLZT films in the composition range 7/0/100-32/0/100 have been deposited by CVD from a single source reagent using a liquid delivery/flash vaporization approach. Single phase perovskite films ranging in thickness from 1-5 μm were deposited on fused silica substrates at 535°C. The films had very strong crystallographic texture with [100] normal to the plane of the film. Optical loss per unit thickness was lower for thicker films suggesting that interfacial effects dominated losses. Very large electro-optic effects were observed in a number of the films. Birefringent shifts were measured by phase retardation in transmission mode with an electric field applied in the plane of the film using interdigitated electrodes. Birefringent shift varied quadratically with applied field and showed little hysteresis with R coefficients as high as 5×10^-16 (m/V)². The strength of the electro-optic effect is attributed to the high degree of crystallinity of the films and the a-axis orientation