The formation of TaNx films by in situ nitrogen implantation with energies
from 0.5 to 5 keV has been investigated in a wide compositional range (0 le
ss than or equal to x less than or equal to 0.92). X-ray photoelectron spec
troscopy (XPS) and valence band x-ray photoelectron spectroscopy (VBXPS) ha
ve been used to characterize the chemical composition and electronic struct
ure of the films, The XPS results show that nitrogen composition is depende
nt on both the ion dose and ion energy. For a given energy the nitrogen com
position increases with increasing ion dose. The composition range obtained
is consistent with a transformation of tantalum nitride from beta -TaN0.05
+ gamma -Ta2N to cubic TaNx + delta -TaN. The VBXPS results indicate a cha
rge transfer from Ta 5d to N 2p hands, and a decrease in the nitrogen vacan
cies concentration during the nitridation process. Copyright (C) 2000 John
Wiley & Sons, Ltd.