RF マグネトロンスパッタリングによる SrTiO_3 薄膜の作製と評価

SrTiO_3 thin films were prepared on various substrates using a rf magnetron sputtering technique with a ceramic target. Optical emission spectroscopy during sputtering was also measured. Emission lines attributed to Sr, Ti, O, O_2^+ and Ar were identified. The oxygen partial pressure affected the emission intensities, which may correlate to the sputtering process and the quality of the deposited thin films. Optical emission spectroscopy was shown to be a useful technique for monitoring oxygen content and ionization probabilities of oxygen in the sputtering gas. The crystalline structure and dielectric properties were studied as functions of substrate temperature and lower electrode type. The X-ray diffraction peak intensities and the dielectric constant of the SrTiO_3 thin films increased with substrate temperature. The dielectric constant of the SrTiO_3 thin films deposited at 580℃ was 255. Strong bias voltage dependence and the maximum capacitance at -1V were observed in the films deposited on both the Pt/SiO_2/Si and Ru/SiO_2/Si substrates. The leakage current density of the 150nm thick films on Pt/SiO_2/Si was 2.5×10^A/cm^2 at 5V.SrTiO_3 thin films were prepared on various substrates using a rf magnetron sputtering technique with a ceramic target. Optical emission spectroscopy during sputtering was also measured. Emission lines attributed to Sr, Ti, O, O_2^+ and Ar were identified. The oxygen partial pressure affected the emission intensities, which may correlate to the sputtering process and the quality of the deposited thin films. Optical emission spectroscopy was shown to be a useful technique for monitoring oxygen content and ionization probabilities of oxygen in the sputtering gas. The crystalline structure and dielectric properties were studied as functions of substrate temperature and lower electrode type. The X-ray diffraction peak intensities and the dielectric constant of the SrTiO_3 thin films increased with substrate temperature. The dielectric constant of the SrTiO_3 thin films deposited at 580℃ was 255. Strong bias voltage dependence and the maximum capacitance at -1V were observed in the films deposited on both the Pt/SiO_2/Si and Ru/SiO_2/Si substrates. The leakage current density of the 150nm thick films on Pt/SiO_2/Si was 2.5×10^A/cm^2 at 5V