Probing capped and uncapped mesoporous low-dielectric constant films using positron annihilation lifetime spectroscopy

Petkov, Mihail P.; Weber, Marc H.; Lynn, Kelvin G.; Rodbell, Kenneth P.
October 2000
Applied Physics Letters;10/16/2000, Vol. 77 Issue 16
Academic Journal
We have measured uncapped mesoporous low-dielectric-constant films using positron annihilation lifetime spectroscopy (PALS), a nondestructive technique, which yields both pore-size distributions and the threshold for pore interconnectivity. Pairs of fully cured capped and uncapped identical films, initially containing 5%-50% porogen additions, exhibited similar signatures in PALS, establishing a technique in which film capping is unnecessary. We also found that it was possible to distinguish between closed and percolated pores, without film capping, by comparing lifetime spectra of a film taken using different detector configurations. Interconnected pores were observed in cured samples, which had greater than 20% porogen additions. © 2000 American Institute of Physics.


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