Thermal oxidation of ruthenium silicide compounds

Ruthenium silicide compounds are a class of interesting semiconducting materials that have
shown promise as oxidation-resistant coatings in modern electronics. Gaining insights into the
oxidation mechanism of ruthenium silicide compounds is relevant for determining if
ruthenium silicide compounds may be used for developing oxidation–resistant coatings. This
work investigates the formation and subsequent thermal oxidation of ruthenium silicide
compounds. The formation of silicide compounds upon UHV annealing of PLD–deposited Ru
on Si(100) substrates is followed using in-situ XPS. Results obtained show that under similar
deposition and annealing conditions, different silicide compounds are formed at the sample’s
surface and a new unidentified peak is observable. The formation of different RuxSiy phases is
characterized using their composition and changes in the shape and position of the plasmonloss peak feature. The thermal oxidation of ruthenium silicide compounds at 350°C and
700°C showed that the ruthenium in ruthenium silicide compounds is extremely resistant to
oxidation when Ru2Si3 is the dominant phase. However, when the dominant phase is
approximately an equiatomic RuxSiy compound, thermal oxidation at 550°C causes ruthenium
to oxidize, thereby resulting in the formation of rutile ruthenium oxide.