A Strategy for Fabricating\nMicroscale Freestanding\nSingle-Crystalline Complex Oxide Device Arrays

We present a general fabrication strategy for freestanding\nsingle-crystalline\ncomplex oxide device arrays via wet chemical etching-based microfabrication\nprocesses and epitaxial lift-off. Here, we used 0.5Ba(Zr<sub>0.2</sub>Ti<sub>0.8</sub>)O<sub>3</sub>-0.5Ba(Zr<sub>0.7</sub>Ti<sub>0.3</sub>)O<sub>3</sub> (BCZT) as a model relaxor ferroelectric oxide system\nand La<sub>0.7</sub>Sr<sub>0.3</sub>MnO<sub>3</sub> as the sacrificial\nlayer for demonstration. Arrays of SrRuO<sub>3</sub> (SRO)/BCZT/SRO\nferroelectric capacitor mesas were first defined and isolated on the\ngrowth wafer, and then they were released using epitaxial lift-off\nwith lithography-defined surrounding etching holes, after which the\nfreestanding device arrays were integrated onto a glass substrate.\nOur proposed strategy sheds light on preparing various freestanding\nsingle-crystalline oxide devices and paves the way for their heterogeneous\nintegration onto arbitrary substates.