Nanoscale luminescence spectroscopy of defects at buried interfaces and ultrathin films

Low energy electron-excited nano-luminescence (LEEN) spectroscopy provides electronic band gap, confined state, and deep level trap information from s emiconductor surfaces and interfaces on a nanometer scale. Correlation of l uminescence features with their spatial location inside a growth structure- either depth wise or laterally-also provides information on the physical or igin and growth dependence of the electronically active defects that form. LEEN spectroscopy of localized states illustrates this approach for a repre sentative set of III-V nitride interfaces, including metal-GaN Schottky bar riers, GaN/InGaN quantum wells, GaN ultrathin films, AlGaN/GaN pseudomorphi c heterostructures across a single growth wafer, and GaN/Al2O3 interfaces. In each case, electronic properties are sensitive to the chemical compositi on, bonding, and atomic structures near interfaces and in turn to the speci fics of the growth process. (C) 2001 American Vacuum Society.