Localized near-band gap studies in nitrides via EELS.

EELS (PEELS) in the extreme-low loss energy range and Energy Loss Near Edge Spectroscopy (ELNES) were carried out in a cold FEG-STEM to study GaN(0001), AlGaN, and AlN. Using cross sectional samples, a study was performed of the variation of near-band gap states when stepping the e-beam parallel to the c direction along threading dislocations and in the perfect material. The aforementioned techniques, along with Energy Dispersive x-rays (EDX), were employed to study the substrate-thin film interface regions. Evidence was found of impurities gettering at dislocations and showed how this method can be used to measure small changes in near band-gap related energy values in a spatially resolved fashion. [on SciFinder (R)]