Effects of deposition temperature on the crystallinity of Ba0.5Sr0.5TiO3 epitaxial thin films integrated on Si substrates by pulsed laser deposition method

Epitaxial Ba0.5Sr0.5TiO3 (BSTO) thin films were grown on TiN buffered Si (0 0 1) substrates by PLD method and the effects of deposition temperature on their crystallinity and microstructure were studied. BSTO thin films were prepared with substrate temperature ranging from 350 to 650 °C. The BSTO films grown at below 400 °C showed amorphous phase and the film grown at 450 °C showed mixed phase of crystalline and amorphous, where crystalline phase was observed only at the top surface portion of the film. The BSTO films with fully crystalline phase were obtained in the samples deposited at above 500 °C. The (0 0 l) preferred orientation and the crystallinity of the BSTO films were improved with increasing the temperature. The dielectric constant, measured at 100 kHz and at room temperature, of the BSTO film grown at 650 °C was measured to be as high as 1129.