Evidence for excess vacancy defects in the Pd-Si system: positron annihilation, x-ray diffraction and Auger electron spectroscopy study

The transformation of Pd/Si to Pd2Si/Si is investigated using depth-resolved positron annihilation, x-ray diffraction and Auger electron spectroscopy studies. The observed defect-sensitive positron S-parameter value of 1.022-1.054 indicates the existence of divacancies across the silicide/silicon interface and Si substrate region. Our experimental observation of vacancy defects is consistent with the model proposed for excess vacancy generation across the interface consequent to Si diffusion. (letter to the editor)