Surface Physical Properties of Ion Beam Sputtered Copper Thin Films on Poly Tetrafluoroethylene

Abstract

In this study thin copper (Cu) films are deposited on poly tetrafluoroethylene (PTFE) substrate using ion beam sputtering technique. The films are characterized using Raman spectroscopy, UV–VIS spectroscopy and atomic force microscope (AFM) techniques. The Raman spectrum shows some decrease in the intensities of Raman bands for Cu/PTFE film than pristine PTFE. UV–VIS transmittance spectra display that the optical transmission reduces from ~75% for pristine PTFE to ~0.20% after 60 min of deposition due to Cu nanoparticles dispersed in PTFE. The surface roughness is increased from 39.4 nm for PTFE to 75.9 nm, while the adhesion force is increased from 9.6 nN to 14.7 nN and Young’s modulus is enhanced from 0.58 GPa to 1.46 GPa after 40 min of Cu deposition time. The DC electrical conductivity at an applied voltage of 200 V is improved from 3.88 × 10–8 S.cm−1 for PTFE to 5.3 × 10–8 S.cm−1 after 60 min of deposition at room temperature. The fabricated Cu/PTFE films exhibit excellent surface properties, which demote that Cu/PTFE films could serve as a low cost material for a broad range of electrical and charge storing devices.