Measuring low dielectric constant film properties during processing

A system for measuring dielectric constant of a low-k dielectric film formed over a reflective layer, said system comprising:

• an ellipsometer that measures an electronic component of said dielectric constant of said low-k dielectric film and produces a measured electronic component;
• an infrared spectrometer that measures an ionic component of said dielectric constant of said low-k dielectric film and produces a measured ionic component;
• a microwave spectrometer that measures an overall dielectric constant of said low-k dielectric film and produces a measured overall dielectric constant;
• and
• means for deriving a dipole component of said dielectric constant using said measured electronic component, said measured ionic component and said measured overall dielectric constant.