Growth and Characterization of BaTiO₃ Sputtered Thin Films at Low Temperature by RF Magnetron Sputtering

Abstract

  We deposited BaTiO₃ (BTO) thin films on Pt/Ti/SiO₂ substrates at the substrate temperatures (T_sub) of 300 and 500℃ in RF magnetron sputtering method, changing sputtering gas flow ratios of oxygen to total gas (R[O₂]) and the distances between substrates and targets (d_T-S). From the results, we found that the (001)-oriented BTO films were obtained at the low T_sub of 300℃ using the d_T-S of 30 mm. The orientation of the BTO films deposited at 300℃ are dependent on the d_T-S from 30 mm to 50 mm. The deposition rates of the BTO films at the d_T-S of 30 mm were larger than those at 40 and 50 mm. Electrical resistance perpendicular to the substrate in the film deposited at 500℃ was higher than that at 300℃. The P_r and E_c of the film at 500℃ were estimated to be 3.4 μC/cm² and 63.5 kV/cm, respectively. (001)-oriented BTO films crystallized at low T_sub of 300℃ is obtained by short d_T-S, since the short d_T-S may supply more materials to the substrates in the plasma where there are many active particles of constituent elements in BTO.