Abstract
Self-cleansing of transition metal nitrides is discovered to take place during ultra-high vacuum annealing of TiN, NbN, and VN thin films. Native oxide layers from air exposure disappear after isothermal anneal at 1000 °C. Also, for TiN, the Ti 2p and N 1s X-ray photoelectron spectra (XPS) recorded after the anneal are identical to those obtained from in-situ grown and analyzed epitaxial TiN(001). These unexpected effects are explained by oxide decomposition in combination with N-replenishing of the nitride during recrystallization. The finding opens up new possibilities for true bonding assignments through non-destructive XPS analyses, thus avoiding artefacts from Ar etching.
Highlights
Self-cleansing of transition metal nitrides is discovered to take place during ultra-high vacuum annealing of TiN, NbN, and VN thin films
Interpretation of X-ray photoelectron spectra (XPS) results obtained in such way always poses a number of questions as to what extent the actual XPS spectra reflect the native material to be studied instead of the ion-beam modified surface layer, which thickness is comparable to the XPS probing depth
We report on a surprising observation that allows for a non-destructive acquisition of high-quality XPS spectra characteristic of a native material from samples that have been exposed to atmosphere
Summary
Self-cleansing of transition metal nitrides is discovered to take place during ultra-high vacuum annealing of TiN, NbN, and VN thin films. Ti 2p signal obtained after the 1000 C in-situ anneal is essentially identical to that of epitaxial stoichiometric TiN/MgO(001) films (epi-TiN) grown and analyzed insitu in a UHV XPS system, as discussed below.25,26 In particular, the satellite features on the high BE side above the primary peaks,27–29 exhibit high intensities comparable to those obtained from epi-TiN.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
