Dielectric Relaxation of La-Doped Zirconia Caused by Annealing Ambient

La-doped zirconia films, deposited by ALD at 300 degrees C, were found to be amorphous with dielectric constants (k-values) up to 19. A tetragonal or cubic phase was induced by post-deposition annealing (PDA) at 900 degrees C in both nitrogen and air. Higher k-values (similar to 32) were measured following PDA in air, but not after PDA in nitrogen. However, a significant dielectric relaxation was observed in the air-annealed film, and this is attributed to the formation of nano-crystallites. The relaxation behavior was modeled using the Curie-von Schweidler (CS) and Havriliak-Negami (HN) relationships. The k-value of the as-deposited films clearly shows a mixed CS and HN dependence on frequency. The CS dependence vanished after annealing in air, while the HN dependence disappeared after annealing in nitrogen.