Effects of plasma oxidation and plasma nitridation on chemical bonding state of AlScN evaluated by AR-HAXPES

The effect of plasma treatment on AlScN films is investigated using angle-resolved hard X-ray photoelectron spectroscopy (HAXPES). As a result, it was observed that the ratio of the oxide component to the nitride component in the AlScN film increased with oxygen plasma treatment. It was also observed that AlScN was less susceptible to oxidation after 1 min of pre-nitridation. Furthermore, the inhibition of oxidation was more pronounced for Sc atoms than for Al atoms. These suggest that the nitridation treatment reduced the number of nitrogen vacancies around Sc atoms. These facts mean that the increase in the on/off ratio of the current in the MIM capacitor can be attributed to the decrease in the number of nitrogen vacancies in the AlScN.