With the development of ultralarge scale integrated circuit, new interlayer dielectrics with low dielectric constant
for multilevel interconnections are required, instead of conventional SiO2 films. For the sake of seeking perfect dielectrics,
amorphous fluoropolymer (AF) thin film with a thickness of about 0.9μm has been prepared by spin-coating method,
following the principle of phase separation. By capacitance-voltage (C-V) measurements the dielectric constant of
the thin film is equal to 1.57 at 1 MHz, which is attributed to numerous pores contained in the film matrix. X-ray
photoelectron spectroscopy (XPS) spectra show that after annealing, about 71% CFa groups in the AF film have
decomposed into CF2, CF, etc. This leads to the increase of CF2 groups by three times and CF groups by 8% in the
AF film. In a word, compared with the film without being annealed, about 25% carbon, 7% fluorine and 12% oxygen
atoms will be lost after annealing at 400℃ for 30min.