Carbon films deposited by low frequency plasma as inter-metal dielectric

We present a study of the correlation between deposition conditions, microstructure, dielectric constant and resistivity of carbon films prepared by low frequency plasma enhanced chemical vapor deposition (LF PE CVD). The carbon films were deposited at relatively high temperature (T=350 °C). The microstructure of the films was studied by IR spectroscopy. The electrical properties were characterized by the measurement of current–voltage characteristics. The correlation between CC, C–HX bonding, resistivity ρ, and dielectric constant K has been found. The effect of isothermal annealing on the structure and dielectric properties has been studied and a correlation between CC and CHX bonding behavior and ρ and K was observed. Ultra low concentration of impurities, resulting from out-gassing of the reactor walls was found to have a great influence on the concentration of CC and CHX bonds, and causes changes in the K and ρ values. For all of the above experiments it is observed the correlation between CC and CHX bonding characteristics with the dielectric properties of the carbon films.