Effect of n‐AlGaN cleave assistance layers on the morphology of c ‐plane cleaved facets for m ‐plane InGaN/GaN laser diodes

The effect of thick n-type Al0.12Ga0.88N cleave assistance layers (CALs) on the morphology of c -plane cleaved facets was investigated for m -plane InGaN/GaN laser diode (LD) ridge waveguide structures. Five LD structures with AlGaN CAL thicknesses ranging from 0 to 800 nm were thinned, scribed, cleaved, and characterized via plan view optical microscopy to evaluate the morphology of the cleaved facets. The fraction of facets that appeared straight across the entire width of the ridge waveguides increased with increasing AlGaN CAL thickness, nearly doubling from a minimum of 43% in samples with no AlGaN CAL to a maximum of 85% in samples with a 600 nm AlGaN CAL. (© 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)