XPS AND AES CHARACTERIZATION OF SINX-H LAYERS DEPOSITED BY PECVD ON PARYLENE-C - EFFECTS OF THERMAL TREATMENTS ON PARYLENE-C SURFACES AND PARYLENE-C SINX-H INTERLAYERS

Comparison of the X-ray photoelectron spectroscopy (XPS) spectra for s urfaces of Parylene C thin layers deposited on alumina substrates with out heating or after various heating times at 150 degrees C revealed a n increase in chlorine concentration near the surface with increasing heating time. After 200 h heating at 150 degrees C, the Parylene C lay er flaked off of the alumina substrate. The deterioration of the Paryl ene C seemed to be related to a chlorine transfer from the bulk of the layer to the free surface. A SiNx:H thin film was deposited on the Pa rylene C layer and characterized by XPS measurements. An Auger study o f the SiN,:H film/Parylene C interface also revealed a chlorine excess in the interfacial region induced by heating the SiNx:H-Parylene C mu ltilayer. However, after 200 h heating of the SiNx:H-coated Parylene C , the polymer appeared to be much less deteriorated than the uncoated film. This better stability of the coated Parylene C polymer seems to be the result of a decrease of the chlorine. loss caused by the presen ce of the SiNx:H barrier.