Role of oxygen pressure during pulsed laser deposition on the electrical and dielectric properties of antiferroelectric lanthanum-doped lead zirconate stannate titanate thin films

摘要

Lanthanum-doped lead zirconate titanate stannate antiferroelectric thin films of ~420 nm with compositions in the antiferroelectric tetragonal region have been prepared on Pt-buffered Si substrates by pulsed laser deposition. Effects of oxygen pressure during deposition were studied, with emphasis placed on the electrical and dielectric properties of the films. The dielectric constant and the maximum polarization increased with the oxygen pressure during deposition, from 75 to 125 mTorr. So did the dielectric strength. This property enhancement with deposition oxygen pressure was believed to be due to the reduction of pyrochlore phase in the films. However, increasing the oxygen pressure beyond 150 mTorr during deposition had led to the increase of surface roughness, which eventually resulted in film cracking. It was also found that increasing the oxygen pressure did not benefit the fatigue performance in any appreciable way.