Characterization of SrRuO3 thin film grown by laser ablation at temperatures above 400 °C

Structural and electrical properties of SrRuO3 thin films grown at various temperatures (Td) were investigated. The films grew epitaxially when Td≧350 °C. The dependences of crystallinity, conductivity, and carrier density on temperature were less pronounced when Td was above 400 °C, whereas crystallinity and conductivity were markedly degraded with decreasing Td when Td≦400 °C. Owing to this unique dependence, SrRuO3 thin film deposited at Td as low as 400 °C showed an acceptable quality for application to electronic devices. For the SrRuO3/SrTiO3/SrRuO3 trilayered capacitor structure, when the top SrRuO3 layer was grown at 400 °C, a symmetric permittivity–voltage curve was observed and the SrRuO3 permittivity value of 340 ε0 was obtained. When the top SrRuO3 layer was grown at 600 °C, the permittivity value of SrTiO3 decreased and even a slight asymmetry of the permittivity–voltage curve could ever be observed. This indicates that the lower temperature deposition of SrRuO3 thin film causes less interface degradation.