High-speed epitaxial growth of SrTiO₃ films on MgO substrates by laser chemical vapor deposition

Epitaxial (100) and (111) SrTiO₃ films were prepared on (100) and (111) MgO single-crystal substrates, respectively, using laser chemical vapor deposition. The effect of deposition temperature (T_dep) on the orientation and microstructure of the SrTiO₃ films was investigated. On the (100) MgO substrates, SrTiO₃ films showed a (111) orientation at a low T_dep of 1023 K. (100) SrTiO₃ films, which were epitaxially grown at T_dep=1123-1203 K, had dense cross sections and flat surfaces with rectangular-shaped terraces. On the (111) MgO substrates, (111) SrTiO₃ films were epitaxially grown at T_dep=983-1063 K; however, these films' orientations became random at high T_dep of 1063-1113 K. The (111) SrTiO₃ films consisted of columnar grains with triangular pyramidal caps. The deposition rates of the epitaxial (100) and (111) SrTiO₃ films were 13-25 and 18-32 μm h^-1, respectively, which is 5-530 times higher than those obtained by MOCVD.