Degradation of chemical composition of porous low-k films under extreme and various vacuum ultraviolet emissions is studied using specially developed sources. It is shown that the most significant damage is induced by Xe line emission (147 nm) in comparison with Ar (106 nm), He (58 nm), and Sn (13.5 nm) emissions. No direct damage was detected for 193 nm emission. Photoabsorption cross-sections and photodissociation quantum yields were derived for four films under study. 147 nm photons penetrate deeply into low-k films due to smaller photoabsorption cross-section and still have sufficient energy to excite Si-O-Si matrix and break Si-CH3 bonds.
Received 17 December 2012Accepted 06 March 2013Published online 18 March 2013
This research is carried out in the frame of MSU-IMEC Agreement and was supported by SRC Program Contract 2012-KJ-2280, the Russian Foundation of Basic Research (12-02-00536-a), Government Grant No. 11.519.11.1008 and Grant MK-6009.2012.2. The authors are very grateful to R&D ISAN (Troitsk, Russia) for providing the experiments with EUV 13.5 nm source.
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