Mesoporous low-k hydrogen-silsesquioxane films characterized by positron annihilation and other techniques

Pore characteristics of hydrogen-silsesquioxane low-k films with various porosities were studied by positron annihilation γ-ray spectroscopy and lifetime measurements. From positron annihilation γ-ray spectra, 3γ annihilation probabilities (I3γ) of incident positrons were determined. I3γ due to the self-annihilation of ortho-positronium escaped out from the film increased with increasing film porosity, indicating the presence of open pores in high porosity films. Positron lifetime measurement showed that the pore is enlarged with increasing film porosity