Fabrication method of GaN template for high-speed chemical lift-off

In this study, a gallium nitride (GaN) template fabrication method for efficient chemical lift-off (CLO) is developed. CLO is slower than other lift-off methods. An air tunnel structure is formed using a photoresist to reduce the process time and improve the etchant penetration rate. Furthermore, an aluminum nitride (AlN) sacrificial layer is mounted on a trapezoid-shaped patterned sapphire substrate. GaN epitaxial growth is observed on the AlN sacrificial layer. The basic physical properties of the grown GaN are investigated using x-ray diffraction, atomic force microscopy, and photoluminescence measurement. The GaN template with the air tunnel structure is depleted by CLO, and the peeling rate is found to be 2.3–6.45 times higher than that reported in the literature.