Annealing behavior and electrical properties of atomic layer deposited PbTiO3 and PZT films

The annealing behavior and electrical properties of lead titanate (PTO) and lead zirconate titanate (PZT) thin films deposited by atomic layer deposition (ALD) were investigated. ALD films were deposited on platinized silicon substrates. The composition of the PTO films ranged from Pb-deficient Pb0.73TiO3−x to Pb-rich Pb2.3TiO3−x, including stoichiometric PbTiO3. The PZT films were all Pb-deficient, with Pb/(Zr + Ti) ratios of 0.40-0.75. Stoichiometric PbTiO3 films showed the perovskite structure, and a well-defined, dense microstructure after crystallization at 600 °C for 1 min in 2 slpm O2 in a rapid thermal annealer (RTA). Pb excess PbTiO3 films developed into perovskite PbTiO3 after annealing but the surface microstructure showed a large grained microstructure with significant porosity. The dielectric constant was 140 at 10 kHz and a ferroelectric polarization - electric field curve was observed. A Pb-deficient Pb0.66Zr0.55Ti0.45O3−x film showed a dense and fine-grained microstructure after annealing at 700 °C for 1 min in 2 slpm O2 in a rapid thermal annealer (RTA). The dielectric constant was 100 at 10 kHz.