CHARACTERIZATION OF AG-IMPLANTED AND W-IMPLANTED POLYIMIDE FILMS

A study has been made of the surface modification of polyimide films by metal-ion implantation. Ag and W ions were implanted in Kapton-H using a MEVVA-type ion implanter. The average energies of Ag and W ions were approximately 130 and approximately 190 keV, respectively. The fluence of implanted ions ranged from 1 x 10(15) to 5 x 10(17) atoms/cm2 with a current density of 1-3 muA/cm2. The target temperature and pressure during ion implantation were nearly room temperature and 5 X 10(-4) Pa, respectively. The composition, structure and chemical bonds of the implanted layers were examined with Rutherford backscattering spectroscopy (RBS), laser Raman spectroscopy (LRS), and X-ray photoelectron spectroscopy (XPS). Sheet resistivity of implanted layers was measured by a four-point probe method. RBS spectra of both implanted specimens show that 0 atoms escaped from the implanted layers, and C atoms were enriched. Raman spectra of both Ag- and W-implanted specimens are similar to that for amorphous-like carbon, which consists of graphite, long-range disordered graphite, amorphous and hydrogenated carbon. The deconvolution of these spectra suggests that the amorphous carbon component is larger for Ag implantation than for W implantation. From the XPS results, implanted Ag atoms are in a metallic state, and W compounds are formed. Sheet resistivity of implanted layers decreases with the increase of fluence in both cases, and the saturated value depends on the implanted species. In conclusion, the carbon structure in carbonized layers is influenced by implanted elements and its resistivity increases as the amorphous component increases.