Heteroepitaxial Growth of High K Dielectric Thin Films by Pulsed Laser Deposition

Abstract

High K dielectric [Pb(Mg1/3Nb2/3)O3]1 − x -[PbTiO3] x (PMN1 − x -PT x ) thin films and conducting La0.7Sr0.3MnO3 (LSMO) oxide electrodes were deposited on LaAlO3 (LAO) (100) single crystal substrates by pulsed laser deposition. A novel “split-target” technique was used to fabricate films with x = 0.00, 0.10, 0.35, 0.53 and 1.00. Conditions for depositing high quality films were studied. The structural characteristics of the PMN1 − x -PT x /LSMO/LAO heterostructures were examined by X-ray diffraction and scanning electron microscopy. A cube-on-cube epitaxy was obtained for films grown at 650°C and under an oxygen ambient pressure of 200 mTorr. Electrical measurement was performed with 0.2 mm diameter patterned Au top electrodes. The dielectric constant and dielectric loss of the PMN1 − x -PT x films were studied as functions of frequency and temperature for x = 0.10 and 0.35. All films grown at 650°C showed small leakage current density of below 10−7 Acm−2 at 1 V.