Ferroelectric single crystal recording media fabricated by polarization controlled wet etching process

Ferroelectric single crystal thin plates are promising materials for ultrahigh-density storage devices. In order to fabricate recording media with large area and high homogeneity, a polarization controlled wet etching process was developed in this paper. Differential etch rates of ferroelectrics are useful in controlling the thickness during the wet etching process. By applying DC voltage to a substrate, the etching process can be stopped when the thickness reaches the desired value. A 455-nm-thick LiTaO₃ thin plate with a diameter of 3 mm was prepared using this method. Nanodomains were artificially formed by applying voltage pulses to the substrate using a metal-coated cantilever top electrode.