VTE - A new method for the characterisation of thin film thermophysical properties

Variable temperature ellipsometry (VTE) is a new non-destructive method for the thermophysical characterisation of (polymeric) materials in the thin film state by combining spectroscopic ellipsometry with temperature dependency. The variation of temperature opens a complete new use of ellipsometry to investigate thin film properties. The method is suitable especially for characterisation of polymeric layers which play an increasing role in microelectronic and microsystem technique. Polymeric materials often show different properties in the nanometer scale compared to the well investigated bulk state or don't exists in the bulk state like plasma polymers or CVDs. For this reason, VTE was developed to investigate the physical properties in the thin film state directly. The method can be used to investigate the following thin film polymeric properties and their thickness dependence in the thickness range from 50 nm to some /spl mu/m: coefficient of thermal expansion, glass transition temperature, thermal degradation, kinetic of evaporation of volatiles (low molecular weight components, solvents), absorption of water, thermal stresses, changes in optical properties.