P. A. Luchnikov, A. A. Rogachev, A. S. Vishnevskiy, A. P. Luchnikov, V. M. Berezin

Films are deposited on the polished silicon wafers surface from an active gas phase in cathodic RF - discharge at the frequency of an electromagnetic field of 13.56 MHz at the vapour pressure of sputtered block polytetrafluoroethylene of 0.4 - 0.5 Pa. The films under study are kept at the open air under normal conditions. It is shown, that electronic processing of a growing polymer layer results in partial destruction of fluoropolymer natural structure with formation of radiating defects. IR - spectra of vacuum films have additional absorption peak in the range from 1660 to 1772 cm-1 as a result of spin - radical groups presence and crosslinking in a molecular network of fluoropolymer. The fluoropolymer composition by X-ray phase spectroscopy shows presence of molecular C-C, C-CF, CF2, CF, СF3 groups in the basic network as well as additional peroxide spin - radical C = O, C-O-C groups. It is established, that vacuum fluoropolymer films prepared in RF-plasma in an external electric field have more perfect molecular structure and the improved electrical properties than films prepared by cathodic RF discharge. Electret films formed at joint influence of plasma and an external electric field have higher charge stability than films deposited without influence of an electric field. Thermal annealing of virgin fluoropolymer films at vacuum at ~ 480 - 580 K during 1.5 - 2 hours essentially improves their electrical properties due to partial recombination of spin - radical groups in polymer.