  We report on an XPS study of AlN thin films grown on Si(100) substrates by
ion beam sputter deposition (IBSD) in reactive assistance of N+/N2+ ions to
unravel the compositional variation of their surface when deposited at
different substrate temperatures. The temperature of the substrate was varied
as room temperature (RT), 100oC and 500oC. The binding energy of Al-2p, N-1s
and O-1s core electrons indicate the formation of 2H polytypoid of AlN. The
increase in concentration of AlN with substrate temperature during deposition
is elucidated through detailed analysis with calculated elemental atomic
concentrations (at. %) of all possible phases at the film surface. Our results
show that predominate formation of AlN as high as 74 at. % is achievable using
substrate temperature as the only process parameter. This high fraction of AlN
in thin film surface composition is remarkable when compared to other growth
techniques. Also, the formation of other phases is established based on their
elemental concentrations.
