Thin films were prepared by reactive magnetron sputtering of polyimide (Kapton) targets using Ar-N 2 discharge gas mixtures. Mass analysis of ions in the discharge space showed that the masses indicating a monomer of polyimide or an imide base were not observed. The compositions of the films investigated by XPS were nitrogen-rich. In the spectra of FTIR, two wide spread peaks corresponding to expansion/contraction mode and angle variation mode of imide or amide base were observed. The thermal stability of the films was relatively inferior to that of bulk Kapton but the wear characteristics of the films were remarkably excellent. The relative dielectric constant of the films adjustable by controlling the N2 gas content in the discharge gas and became 3 or less.
