Pulsed laser deposition of electroceramic thin films

Sintered targets of BaTiO3 are ablated by KrF excimer laser radiation (λL = 248 nm) with pulsed-laser deposition (PLD) in order to produce electroceramic thin films for dielectric and ferroelectric applications. Plasma formation and expansion is observed by a time-of-flight (TOF) setup with time-resolved (10 ns resolution) plasma emission spectroscopy (PES) in the 200 to 900 nm wave length range. Thin films with tetragonal crystalline structure and a dielectric constant up to 790 are deposited on Si(111)/Ti/Pt substrates. Ellipsometry is used to determine the influence of the laser cross-section geometry on the target surface on the film thickness homogeneity. The influence of beam parameters on particle speed in the plasma and on the electrical and structural properties of deposited films is presented. The chemical composition of the thin films as a function of processing variables is characterized by X-ray photoelectron spectroscopy (XPS). Crystalline structure is analysed by Raman-microprobe spectroscopy (RMP) and X-ray diffraction (XRD). Electrical characterisation is done by impedance measurements.