Depth-resolved impact of integration process on porosity and solvent diffusion in a SiOCH low-k material

摘要

The impact of plasma etching and chemical wet cleaning on solvent diffusion in porous network of a SiOCH low-k dielectric material is studied. Characterization of porosity and pore size distribution by means of ellipso-porosimetry and positron annihilation lifetime spectros-copy are presented. The results are compared with solvent diffusion kinetics, measured using probe molecules of different polarity, surface energies and molecular sizes. Infrared spectroscopy, Doppler broadening of annihilation radiation and time-of-flight secondary ion mass spectrom-etry measurements are also performed to investigate material modifications causing variations of diffusion kinetics.