Bond nature of oxygen-deficient HfO2/Si(100) film

The authors investigate the bonding environment of an oxygen-deficient HfO2/Si film grown by means of pulsed laser deposition, by analyzing the Hf L-3-edge extended x-ray absorption fine structure. The local characteristics around the Hf atom, such as the bond length or the number of nearest neighbors, are found to depend on the oxygen supply during film growth. The chemical states of these samples are also probed in situ by x-ray/ultraviolet photoelectron spectroscopies. The core-level binding energy and the work function for each sample are found to be correlated with the mean Hf-O bond length, implying a close connection between the chemical environment and bond nature. (c) 2006 American Institute of Physics.