Surface confinement of the InN-rich phase in thick InGaN on GaN

The surface confinement of InN-rich phase in thick In0.15Ga0.85N epitaxial films on GaN were observed by photoluminescence depth profiling employing an inductively coupled Cl2 plasma etching technique. The photoluminescence measurements showed that InN-rich phases were present on the surface of the thick In0.15Ga0.85N films. After removing the surface layer of 50 nm, the PL peaks corresponding to the InN-rich phases completely disappeared, suggesting that the InN-rich phase region is confined to a depth of 50 nm.