Thin film GaN-based membranes by laser lift-off and cleaved In GaN LD facet

Thin gallium nitride films,grown on sapphire substrates by MOCVD,are debonded by laser-induced lift-off. 3μm thick GaN membranes and 5μm thick InGaN MQW LD membranes are successfully separated from the growth substrates using KrF pulsed-excimer laser.Characterization of laser lift-off technology between wafers with sapphire substrates backside polished and wafers with sapphire substrates backside unpolished are compared.The threshold intensities are about 200mJ/cm2 and 300mJ/cm2 for these two kinds of wafers,and incident pulse intensities of 400mJ/cm2 and 600mJ/cm2 were required for stable interface splitting respectively. The InGaN MQW LD films are transfired onto a Si or InP support substrate and then cleaved. SEM was employed to analyze the cleaved facet. It can be concluded that the cleaved facet is ideal. GaN-based opto-electronic and electronic devices without sapphire substrate are available with this technology.