Organic thin films with defined chemical structures and physical,properties are required for various applications. Plasma polymerization is of technological interest, since the deposition of plasma polymers is possible on any material of any shape in the desired thickness. We report on the TOF-SIMS (TOR time-of-flight) and XPS investigations of pulse plasma 'poly(acetylene)' and alkali metal doped pulse plasma 'poly(acetylene)' films. The combination of TOF-SIMS and XPS supplies detailed information,on the surface chemistry of these films. Application of both methods provides the possibility for cross-checking certain results. Moreover the different sensitivities of the methods can be utilized, According to the TOF-SIMS and XPS data it can be concluded that the interaction of alkali metals with plasma 'poly(acetylene)' results in electrovalent bonds of the type Medelta+-Cdelta- between carbon and metal. Furthermore carbon-oxygen-metal interactions were observed. These interactions are of the type C=Odelta-...Medelta+ and/or C-Odelta--Medelta+. (C) 2002 Elsevier Science B.V. All rights reserved.