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

Abstract

The over-volume defects of hydrogen-silsesquioxane (HSSQ) and methyl-silsesquioxane (MSSQ) spin-on-glass films were examined by Doppler broadening positron annihilation spectroscopy. A simple correlation between the total open volume and the permittivity of the films was established. In conjunction of the inherent depth resolution of the variable energy positron beams, the relation between the shape of the annihilation line at each depth and the permittivity allows a nondestructive depth profiling of the permittivity of homogeneous, as well as inhomogeneous films.