Modification of parylene AF-4 surfaces using activated water vapor

In this study, we investigate the addition of oxygen functionalities to parylene AF-4 using X-ray photoelectron spectroscopy (XPS). Subsequent reactions with trimethylaluminum (TMA) were also studied by XPS. Samples were exposed to water vapor that was passed over a heated W filament, and comparison is made with similarly exposed polystyrene. Oxygen incorporation occurred in both polymers and was substantially greater in polystyrene. Defluorination occurred in the parylene sample, and X-ray photoelectron spectra indicate that the oxygen is chemically bound to the polymer surface. TMA was dosed at room temperature onto the parylene samples, and prior modification of the AF-4 surface resulted in enhanced reactivity toward TMA. Atomic force microscopy (AFM) is used to characterize the surfaces and demonstrates that no significant surface roughness occurred due to the modification process. (C) 1999 Elsevier Science B.V. All rights reserved.