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(Pb, La)TiO3(PLT, La/Ti=0.17) thin films were prepared by multiple cathode rf-magnetron sputtering. The electrical properties of these films were investigated. The PLT thin films deposited on Pt/MgO substrates exhibited higher crystallinity and better ferroelectric properties, compared to the films deposited on Pt/SiO2/Si substrates. The hysteresis loops of the PLT films on RuO2/Ru/SiO2/Si or RuO2/Ru/MgO were narrow compared to that of film deposited on platinum electrodes. The dielectric constant of PLT films deposited at 540° C decreased with decreasing film thickness. Existence of a Pb-deficient layer near the film/substrate interface was observed by X-ray photoemission spectroscopy (XPS) analysis. By lowering the substrate temperature to 515° C, Pb re-evaporation from the substrate decreased, and ferroelectric properties were improved. By controlling the Pb/Ti incident ratio, thin films with different Pb contents of the interface layer were formed. With an increase in the Pb content near the film/substrate interface, the fatigue resistance increased.

Ru and RuO2thin films were prepared by RF magnetron sputtering. The crystalline structure and electrical properties of these films were investigated. Reactive sputtering of a ruthenium metal target was carried out in a mixed gas of argon and oxygen at 580° C. Total pressure (PO2+PAr) was controlled to maintain a constant pressure of 1 Pa. The RuO2single phase could be obtained when PO2was 0.5 Pa and the deposition rate was about 30 nm/min. The resistivity of the 290 nm-thick RuO2thin films deposited on SiO2(1000 nm)/Si was 54.9 µ ?· cm. However, the resistivity increased with decreasing film thickness. Fatigue resistance of (Pb, La)TiO3thin films with RuO2as top and bottom electrodes was improved compared to the films on Pt electrodes.

The ferroelectric fatigue and refreshment of (Pb, La)TiO3thin films by multiple cathode rf-magnetron sputtering were investigated. The remanent polarization of the fatigued (Pb, La)TiO3thin films increased after the application of the DC bias voltage of -20 V for 104s. By heat treatment of the fatigued films at 400° C for 1 h, the coercive field decreased, and squareness of the loop was improved. These behaviors were discussed from the viewpoint of the behavior of defect dipoles.

The ferroelectric properties of (Pb, La)TiO3thin films fabricated by multiple cathode rf-magnetron sputtering were investigated. After argon ion etching of the (Pb, La)TiO3thin films, the reduction of Pb-O bonds, shift of hysteresis loop on the E-axis and the decrease of remanent polarization was induced. After heat treatment at 700° C in N2, squareness and saturation of the loop worsened, and remanent polarization decreased. After reheat treatment of the films at 400° C for 1 h, the coercive field decreased, and the squareness of the loop was improved. These results were discussed from the viewpoint of the behavior of space charge.

The preparation of PbTiO3thin films by multiple cathode rf-magnetron sputtering was investigated. The effects of incident Pb/Ti ratio, the kind of substrates, substrate temperatures and film thickness on the crystalline structure of the PbTiO3thin films prepared were studied. The thin films with perovskite PbTiO3structure on Si wafers were obtained by deposition at an incident Pb/Ti ratio of 1.2 at a substrate temperature of 460?500°C. The X-ray photoemission spectroscopy (XPS) depth profile revealed that less reaction of the thin films with the Si substrate was observed at the interface at lower substrate temperatures.