Oxygen chemiluminescence in He plasma as a method for plasma damage evaluation

We propose a method for evaluating the hydrophilisation degree of low-k films upon plasma damage. The evaluation is based on optical emission spectroscopy analysis of O∗ emission during He plasma exposure of sample in question. The O∗ is presumably desorbed from damaged low-k film by vacuum–ultraviolet radiation from He plasma. The new method correlates well with other methods for plasma damage characterization such as Fourier Transform Infrared Spectroscopy and Water–Vapor Ellipsometric Porosimetry. The presented method gives a unique opportunity to assess the degree of hydrophilisation of low-k films immediately after processing.