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.