Fabrication of Amorphous Carbon Thin Film from CH4 Using PEVCD

Abstract

Thin films of amorphous carbon have successfully been fabricated by radio frequency-plasma enhanced chemical vapor deposition (RF-PECVD). Carbon film fabrication with a methane gas (CH4) source has been fabricated with deposition parameters: 15 Watt of RF power, 13.5 MHz of frequency, 100 °C of substrate temperature, 450 m Torr of pressure and 120 minutes of deposition time. Methane gas flows were 40, 60, 80 sccm, respectively. Thin film can be in the form of DLC, Graphite or Amorphous Carbon depending on the ratio of hybridized orbitals of sp3, sp2 and sp. The X-ray diffractrometry (XRD) show the amorphous phase of the thin film has been formed. Further analysis using Fourier transform infrared (FTIR) combined with synchrotron photoemission spectroscopy (PES) showed that the sp3 hybridization was more dominant than sp2. This gives an indication that as fabricated thin films are tetrahedrally amorphous carbon (ta-C). Keywords: Amorphous carbon, methane gas, thin film.