Effect of implantation temperature on the H-induced microstructural damage in AlN

A detailed physical investigation of the H-induced microstructural damage in (0001) AlN epitaxial layers at various implantation temperatures is presented. Cross-sectional transmission electron microscopy revealed that in the case of samples implanted at 300 C, extended defects (nanocracks) were formed only within � 50 nm region situated below the H-concentration peak in the damage band of width � 280 nm compared with lower implantation temperatures. This implantation temperature-dependent behavior of the microstructural damage decides the morphology of the top buckled surface. Various favorable conditions for the buckling of H-implanted surface in the form of large area exfoliation are proposed based on the present study.