Efficiency evaluation of postetch metal stack anticorrosion treatments using chemical analyses by x-ray photoelectron spectroscopy and wide dispersive x-ray fluorescence

Abstract

Chemical analyses by x-ray photoelectron spectroscopy (XPS) combined with wide dispersive x-ray fluorescence (WDXRF) have been used to evaluate the efficiency of metal stack anticorrosion treatments previously etched in a low-pressure high-density plasma source. Analyses demonstrate that residual chlorine is still present in the metal stack showing that corrosion could occur in the subsequent technological steps of the process. In particular, XPS analyses have shown that, after anticorrosion treatment, residual chlorine species are located on the aluminum sidewalls of the features. Combining the results obtained by WDXRF and XPS has allowed a better understanding of the action of anticorrosion treatments.