スパッタ中の酸素分圧によるPbTiO₃スパッタ薄膜の微細構造変化

抄録

Thin films of PbTiO₃ (PT) were epitaxially grown on miscut (001)SrTiO₃ (ST) substrates with various partial oxygen pressures during the sputtering deposition. Under a low partial oxygen pressure (Ar/O₂≥20/5) the film growth was governed by a step-flow resulting in a continuous structure with a flat surface. Under a higher partial oxygen pressure (Ar/O₂≤20/6) the sputtered films showed island structures with micro-pinholes. It is considered that the excess oxygen will reduce the surface mobility of adatoms which induces the island growth. XRD analyses showed that the increase of partial oxygen pressure increased the full width at half maximum intensity of the PT thin films, although these sputtered films showed a single crystal of PT with (001) orientation. The partial oxygen pressure is essential for the control of microstructure.