Speetroscopic Ellipsometry as a Potential In-Line Optical Metrology Tool For Relative Porosity Measurements of Low- K Dielectric Films

摘要

The optical properties of organosilicate glass (OSG) samples were investigated with spectroscopic ellipsometry. We found that samples with dramatically higher hardness had higher indices of refraction (RI) and thus higher electron densities and lower relative porosities than films with lower hardnesses. The reverse was true for films with low hardnesses. As well, these films did not have the same optical properties as porous SiO_2 across the spectral range measured, which we show has significant implications for the in-line optical metrology of these materials.