Effects of ion bombardment on chemical interactions at SiC surface and Al/SiC interfaces

An investigation into the SiC surface and its interaction with aluminum, in particular, focusing on the effect of ion bombardment and adsorption of oxygen, is described. Stoichiometric and carbon rich and SiC surfaces were produced and analyzed in situ by Auger electron spectroscopy and x-ray photoelectron spectroscopy. Cubic SiC shows preferential sputtering under Ar ion bombardment, leading to carbon rich surface, whereas high temperature annealing also causes carbon rich surface. Activity of these surfaces was compared with oxygen and aluminum adsorption. Stoichiometrically sputtered surface showed vastly increased oxygen affinity, whereas carbon-rich sputtered surfaces did not. Aluminum deposition caused significant Al-C interaction for the stoichiometric ion-bombarded surface. Aluminum carbide was induced catalytically upon heating in the presence of oxygen. Carbon-rich surfaces had, however, no significant interactions with as-deposited Al due to strong surface C-C bonds