Large etch-selectivity enhancement in the epitaxial liftoff of single-crystal LiNbO3 films

Abstract

We report on a large etch selectivity enhancement in the epitaxial liftoff of He+-implanted single-crystal lithium niobate (LiNbO3) films upon rapid thermal annealing. A buried sacrificial layer is formed by ion implantation. Heat treatment is found to reduce the time needed for film detachment by a factor as large as 100. Implant damage and postanneal stress-induced etch selectivity become nearly independent of implantation energy upon annealing. Large (0.5×1 cm2) 5–10-μm-thick single-crystal LiNbO3 films of excellent quality are detached in just a matter of a few hours.