Doppler broadening positron annihilation spectroscopy: A technique for measuring open-volume defects in silsesquioxane spin-on glass films

Abstract

Doppler broadening positron annihilation spectroscopy is used to measure the concentration, spatial distribution, and size of open-volume defects in low dielectric constant (low-k) hydrogen- and methyl-silsesquioxane thin films. A simple correlation between the number of open-volume defects and the dielectric constant is obtained. In addition, the depth-resolving capability enables profiling of the local electronic environment of open-volume defects as a function of depth. The potential for using this technique for measuring k as a function of film depth is also discussed.