The effects of plasma treatment on the surface properties of Si-doped Al 0.5Ga 0.5N were studied by X-ray photoelectron spectroscopy and metal contact measurements. Plasma treatment resulted in a N-deficient nonstoichiometric AlGaN surface with an increased O concentration and large red shifts of photoelectron peaks. The red shifts remained after removal of the surface oxide, indicating a downward shift of the surface Fermi level as a result of ion-induced compensating defects. Pre-metel plasma treatment led to more rectifying electrical characteristics of Ti/Al/Ti/Au contacts. Current-voltage characterization at elevated temperatures revealed strong compensating effects of the plasma damage in Al 0.5Ga 0.5N even at 300°C.
|Number of pages||7|
|Journal||Physica Status Solidi (A) Applications and Materials Science|
|State||Published - Oct 2007|