Bonding properties and their relation to residual stress and refractive index of amorphous Ta(N,O) films investigated by x-ray absorption spectroscopy

This work presents N, O K-edge x-ray absorption near-edge structure (XANES) and Ta L-3-edge extended x-ray absorption fine structure (EXAFS) studies of amorphous Ta(N,O) films prepared with various flow rate ratios of N-2/O-2. The N and O K-edge XANES and Ta L-3-edge EXAFS spectra demonstrate the presence of N-2 molecules. These spectra also show that Ta(N,O) films have similar local atomic structure as. that of Ta2O5. No evidence of the formation of Ta-N bond was obtained. The intensities of the pi* feature in the N K-edge spectra and the features of O 2p-Ta 5d hybridized states were found to correlate with the residual stress and the refractive index, respectively. (c) 2005 American Institute of Physics.