Spalling-induced β-Ga2O3 lift-off protocol

Fabrication of gallium oxide 1–100 µm-thick layers by exfoliation them from single crystals opens up the way to provide good thermal management in high-power Ga₂O₃ devices. Here we propose a lift-off protocol based on spalling of homoepitaxial layers from (100) β-Ga₂O₃ bulk crystal. The process includes sputtering of Ni sacrificial mask on β-Ga₂O₃ substrate and its modification by annealing, prior to epitaxial layer deposition in mist-CVD reactor. The separated 4 μm-thick β-Ga₂O₃ layers have been studied. It is shown that implementation of the lift-off protocol allows obtaining high-quality free-standing layers.