Flash‐Lamp Annealing for Repairing Residual Defects in Single‐Crystalline LiTaO ₃ ‐On‐Silicon Thin Films Fabricated by Crystal Ion Slicing

Single‐crystalline lithium tantalate (LiTaO 3 ) thin films fabricated on silicon substrates via crystal ion slicing inherently contain implantation‐induced defects and residual thermal stress, which severely limit their device performance. In this work, flash‐lamp annealing (FLA) with energy densities ranging from 10 to 50 J/cm 2 was employed to repair transferred LiTaO 3 thin films. Rutherford backscattering spectrometry with channeling analysis revealed a pronounced reduction of Ta displacement atoms after FLA. X‐ray diffraction demonstrated the disappearance of satellite peaks and a narrowing of the main Bragg peak, confirming strain relaxation and improved crystalline quality. Raman spectroscopy showed enhanced LiO and TaO vibrational modes, consistent with improved crystallinity. The LiTaO 3 thin films exhibited the best recovery at an FLA energy density of 40 J/cm 2 , the maximum energy level they could withstand without cracking. These results demonstrate that millisecond‐range FLA is a rapid and wafer‐compatible approach for eliminating residual defects and stress in LiTaO 3 thin films, offering a promising alternative to conventional furnace annealing. This strategy may also be extended to other heterogeneously integrated thin‐film systems to enhance their structural and functional properties.