Synthesis and Properties of Ba(Ti,Sn)O3 Films by E-Beam Evaporation
Ba(Ti,Sn)O3 thin films, for use as dielectrics for MLCCs, were grown from Sn doped BaTiO3 sourcesby e-beam evaporation. The crystalline phase, microstructure, dielectric and electrical properties of films wereinvestigated as a function of the (Ti+Sn)/Ba ratio. When BaTiO3 sources doped with 20~50mol% of Sn wereevaporated, BaSnO3films were grown due to the higher vapor pressure of Ba and Sn than of Ti. However, itwas possible to grow the Ba(Ti,Sn)O3 thin films with ≤15mol% of Sn by co-evaporation of BTS and Ti metalsources. The (Ti+Sn)/Ba and Sn/Ti ratio affected the microstructure and surface roughness of films and thedielectric constant increased with increasing Sn content. The dielectric constant and dissipation factor ofBa(Ti,Sn)O3 thin films with ≤15mol% of Sn showed the range of 120 to 160 and 2.5~5.5% at 1KHz,respectively. The leakage current density of films was order of the 10−9~10−8A/cm2 at 300KV/cm. The researchresults showed that it was feasible to grow the Ba(Ti,Sn)O3 thin films as dielectrics for MLCCs by an e-beamevaporation technique.