How to evaluate surface free energies of dense and ultra low-k dielectrics in pattern structures

A method to evaluate the surface free energy in pattern structure, of chem. vapor deposited dense and ultra low-κ (ULK) SiOCH dielec. films, is presented. Therefore dense and ultra low-κ films were treated by different post ash plasma processes. This films were characterized using Auger electron spectroscopy, at. force microscopy and contact angle measurements. For both material systems a correlation between the amt. of surface near carbon and the surface free energy was found, independent on the plasma chem. used. The range of the surface roughness is very small and does not have a strong impact on the surface free energy. The correlation model can be applied for pattern structures. After measuring the carbon concn. at the side walls by methods like TEM-EELS or other the model provides the polar and dispersive part of the surface free energy. Having the surface free energy, contact angle of different liqs. on or in pattern structures can be calcd. Hence, the wetting beh