Characterization and aluminum metallization of a parylene AF-4 surface

The surface of vapor deposited parylene AF-4 [poly(alpha,alpha,alpha',alpha'-tetrafluoro-p-xylylene)] was characterized by atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). Subsequent interactions with trimethylaluminum (TMA) were studied by XPS. TMA was adsorbed onto an unmodified parylene AF-4 sample (30 L, 112 K). The sample was then annealed to 300, 550 and 600 K (sequentially) in ultra-high vacuum. A reaction occurs between the precursor, the polymer surface and physisorbed water at or below 300 K, producing Al-C, Al-O and Al-F bonds as evidenced by changes in the XPS spectra. The reaction produces a thermally stables aluminum-oxide film bound to the polymer through aluminum-carbon bonds. A fluorine concentration gradient exists in the form of a fluorinated aluminum oxide across the film, with increasing fluorination toward the adlayer/polymer interface. (C) 1998 Elsevier Science B.V.