Plasma oxidation as key mechanism for stoichiometry in Pulsed Laser Deposition grown oxide films

Abstract

We present a unique overview on the influence of growth parameters on the characteristics of the PLD plasma plume using Optical Self-Emission (OSE) imaging and spectroscopy, supported with Laser Induced Fluorescence (LIF) measurements. It is shown that in a relatively small background gas pressure regime, from 10-2 mbar to 10-1 mbar oxygen pressure, a transition from nonstoichiometric to stoichiometric growth of SrTiO3 films occurs as measured with X-ray Diffraction (XRD). In this pressure regime, OSE spectroscopy and LIF measurements also show a transition from incomplete to full oxidation of species in the plasma plume. This suggests that the oxidation of species in the plasma is a crucial mechanism for the stoichiometric reconstruction of the synthesized oxide thin films