Significant suppression of island growth in epitaxial (Pb,La)(Zr,Ti)O₃ thin films by two-step growth technique

抄録

(001)-epitaxial (Pb_0.91La_0.09)(Zr_0.65Ti_0.35)O₃ (PLZT) ferroelectric thin films were fabricated on SrTiO₃ and MgO substrates, with an SrRuO₃ bottom electrode layer, using pulsed laser deposition. When films were deposited in a single step at a high temperature conventionally used for epitaxial growth, island growth was observed. To suppress the island growth, we used a two-step growth technique. First, a thin initial layer was deposited at a low temperature to promote rapid strain relaxation from the lattice mismatch. Consequently, the island growth was suppressed and when a second layer was deposited at high temperature, a remarkably flatter surface was achieved as compared with that of conventional one-step-grown films. The two-step-grown PLZT films are promising for use in ferroelectric thin film-based plasmonic electro-optic devices.