The influence of carbon content in carbon-doped silicon oxide film by thermal treatment

Abstract

Carbon-doped silicon oxide (SiOC) low- k dielectric film was deposited on a p-type Si(100) substrate with mixture of bis-trimethylsilylmethane (BTMSM) and oxygen by inductively coupled plasma chemical vapor deposition (ICPCVD). Electron density and electron temperature of ∼10 12 cm −3 and 1.6 eV, respectively, were obtained at low pressure (<300 mTorr) and radio frequency (RF) power of approximately 300 W. Fourier-transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS) were used to investigate the bonding configurations, porosity and atomic concentrations within the films. The carbon content increased and the film density decreased in films annealed at 400 °C in vacuum. SiOSi and SiOC bonds were separately identified in the bonding structure of SiOC composite films. We can deduce the existence of caged SiO bonds and enhanced porosity of the film from these results. The dielectric constant of the SiOC composite film depends on the relative carbon content and the pore density. The porosity calculated is 68% when the dielectric constant is approximately 2.1.