Crack-Free Laser Lift-Off of Epitaxial Oxide Superconductor Films

Integrating the outstanding functionality of biaxially textured materials with technologically desirable non-native substrates remains a challenge in material science. Laser lift-off (LLO) of single-layer epitaxial films is a straightforward path, but there has been limited successful examples, such as GaN and Pb(Zr,Ti)O₃, that question the applicability of the solution path to a wide range of compounds. Here, we report a crack-free millimeter-scale transfer of epitaxial YBa₂Cu₃O_7-x films via LLO from native single-crystalline substrates to silicon, fused silica, and polyimide substrates. Our standard characterization measurements suggest relatively intact structural and superconducting properties of the transferred films, except for a 130 nm thick amorphous layer formed at the laser-irradiated surface. Notably, we also found a correlation between the texture quality of a target film before LLO and the microcrack formation at LLO, thus suggesting that the grain boundaries in our successful films effectively relieved the stress exerted by the laser irradiation and prevented microcracks. Our results not only demonstrate a simple route of integration between high-temperature superconductivity and abundant substrates but also suggest versatility of LLO in epitaxial films with controlled texture quality.