Selective Growth and Micropatterning Technique for Oxide Thin Films by Sacrificial a-CaO Layer

Abstract

Selective growth and micropatterning through a water lift-off (WLO) process utilizing a sacrificial amorphous CaO (a-CaO) layer were demonstrated to fabricate hetero-epitaxial all-oxides film capacitors. Patterned Pb(Zr,Ti)O 3 (PZT) and SrRuO 3 (SRO) films were grown on (100) SrTiO 3 (STO) substrate by pulsed laser deposition, and the subsequent lift-off process for target oxides was carried out using pure water. The results showed that selective growth and micropatterning of an all-oxides capacitor structure could be realized through WLO process using a-CaO as the sacrificial layer. Electron backscattered diffraction results revealed that SRO/PZT/SRO capacitor structures were grown hetero-epitaxially on the STO substrate. Furthermore, the electrical properties of patterned SRO/PZT/SRO film capacitors could be improved by suppressing the height of overgrown parts of the SRO bottom electrodes with a thick a-CaO sacrificial layer.