Spectroscopic and capacitance-voltage characterization of thin aminopropylmethoxysilane films doped with copper phthalocyanine, tris(dimethylvinylsilyloxy)-POSS and fullerene cages

We report on studies about novel 3-aminopropyltrimethoxysilane (APTMS) based hybrid composites doped by copper phthalocyanine (CuPc), [6,6]-phenyl-C61-butyric acid methyl ester and tris(dimethylvinylsilyloxy)-POSS (POSS). APTMS was used as siloxane matrix in order to produce thin layers of composite materials spin-coated onto silicon. The surface chemistry and the dielectric properties were investigated by the combination of X-ray photoelectron spectroscopy and capacitance voltage technique. We observed strong correlations between the dopant concentration and the chemical composition, homogeneity and electrical properties (permittivity, hysteresis) of the produced layers. Hence, an increase of the surfaces chemical resistance against the ambient conditions due to the POSS incorporation into the siloxane matrix was found. Furthermore, this work demonstrates that a properly chosen concentration of CuPc and POSS dopants within the siloxane matrix leads to homogenous films with an extremely low dielectric constant in the range of 1.8.

► The combination of the XPS and CV techniques. ► The incorporation of POSS within the APTMS based material increases the surface resistance against the ambient influence. ► The application of POSS and CuPc dopants allowed to decrease the composite dielectric constant to 1.8. ► CuPc molecules decrease the hysteresis inside the CV measurements of the composite film.