Correlation between crystallization and oxidation process of ScN films exposed to air

Oxidation and hydrolysis are two spontaneous reactions occurring when scandium nitride (ScN) is exposed to air (oxygen and humidity). In order to evaluate the detrimental effect of the oxidation on functional properties of the material, ScN films were prepared under ultrahigh vacuum conditions at 700 degrees C onto two different substrates; crystalline MgO(0 0 1) and amorphous fused silica. X-ray Photoelectron Spectroscopy analysis was performed to study the oxidation reactions. The study also employed vacuum transferred pristine samples. Crystalline quality and oxidation resistance were found to be strongly correlated. Degradation of electrical and optical properties was observed for polycristalline films prepared on fused silica. On the other hand, highly ordered crystalline films grown on MgO(0 0 1) demonstrated surface passivation preventing further progress of the oxidation. Post-deposition exposure to air was found to be a principal source of the observed oxidation.