Plasma polymerization of fluorocarbon thin films on high temperature substrate and its application to low-k films

Amorphous fluorinated carbon films have been prepared by plasma enhanced chemical vapor deposition method using C6F6 at substrate temperature of 400 °C. Thermal stability up to 400 °C is automatically achieved. Dielectric constant of the films is 2. Infrared absorption spectra of the films have indicated that the films contain benzene rings, and F/C ratio is unity as seen in monomer molecules. No film deposition has been observed if C5F8 is used as a source monomer at this substrate temperature. In situ Fourier transform infrared spectroscopy of C6F6 plasma has indicated production of C6F5 because C12F10 has been observed. This result and inclusion of benzene rings in the films suggest that a possible deposition precursor is C6F5.