Investigation of low dielectric carbon-doped silicon oxide films prepared by PECVD using methyltrimethoxysilane precursor

Carbon-doped silicon oxide (SiOC(-H)) films with low dielectric constant were deposited on a p-type Si(100) substrate using inductively coupled plasma chemical vapor deposition with methyltrimethoxysilane (MTMS:CH3Si(OCH3)3) precursor and oxygen gases. Fourier transform infrared spectroscopy was used to investigate the bonding configurations and atomic concentrations within the films. The dielectric constant of SiOC(-H) composite film depends on the relative carbon concentration and the content of the ring link mode in SiOC(-H) bonding structure. The lowest dielectric constant of an annealed film at 400 °C was 2.25, which was deposited with [MTMS / (MTMS + O2)] flow rate ratio of 100%.