Plasma procedures were used for the deposition of polymer barrier layers that are highly cross-linked as a consequence of the molecular fragmentation of the feed gases. Plasma polymers from vinyltrimethysilan (VTMS) as feed gas showed good protection against chemical and electrochemical attacks on gold (against 4 M H2SO4). A combination of a plasma-VTMS primer covered by a plasma hydrocarbon layer showed good resistance against alkaline corrosion on aluminium. (C) 1998 Published by Elsevier Science S.A.