In Situ Spectroscopic Examination of Plasma Emission during Excimer Laser Deposition of Pb0.95La0.05(Zr0.7Ti0.3)0.9875O3 Thin Films

The optical emission spectra radiated from the laser-induced PLZT plume under various levels of laser fluence and oxygen pressure were systematically examined. The plasma temperature of Ti species corresponding to each spectrum was estimated using the Boltzmann plot technique. No emission belonging to diatomic species was observed. For the Pb species, only the spectral lines from excited neutral atoms were observed. For the Ti and Zr species spectral lines from both excited neutral atoms and singly ionized ions were obtained. The intensity of the spectral lines increased with the laser fluence when the oxygen pressure (P O2) was kept constant. The plasma temperature of the Ti species varied insignificantly with the laser fluence under P O2=0.1 mbar. On the other hand, the spectral intensity markedly decreased and the plasma temperature significantly increased when P O2 level was reduced to below 0.01 mbar. The plasma temperature changed only moderately, when P O2 increased from 0.1 mbar to 1 mbar. The crystallinity of thus obtained PLZT films varied with the oxygen pressure.