In Situ Monitoring in the Pulsed Laser Deposition of Ferroelectric Thin Films

ABSTRACTOptical multichannel emission spectroscopie studies and ICCD (intensified charge coupled device) imaging have been applied to real-time, in situ gas phase species identification and plume structure analysis during the pulsed excimer laser deposition (PLD) of various ferroelectric thin films. Additional information on the non-excited plume species has been obtained using molecular beam-sampling mass spectrometry. The materials studied included targets of PbZr0.53Ti0.47O3 (PZT) and BaTiO3. For the BaTiO3 films, the partial pressure of oxygen in the buffer gas and the atomic oxygen emission within the plume both correlated with the observed lattice parameter, as determined by X-ray analysis. Reduced plume oxygen content resulted in an increased lattice parameter that, in turn, could be related to a reduced oxygen content in the film. ICCD imaging of plumes from PZT targets identified the presence of ejected particulates in the plume after multiple laser shots had worked the target surface. Scanning electron microscopy (SEM) studies of the PZT target surface and film morphology, revealed cone-like formations on the target and éjecta on the films which correlated well with the ICCD observation of plume particulates.