Liquid Phase Deposition of Carbon Nitride Films for Application as Low-k Insulating Materials

CNx films are fabricated using liquid phase deposition by applying a DC bias voltage to Si substrates immersed in acrylonitrile. X-ray photoelectron spectra reveal that C, N, and O are major components of the deposited films. From analysis of C 1s and N 1s spectra, the major bonding state in the CNx film is attributed to a mixture of C≡N and partially hydrogenated C=N bonds. Metal–insulator–semiconductor capacitors incorporating the CNx insulating layers are fabricated to evaluate the electrical properties of the deposited films. The lowest dielectric constant k of the CNx film is determined to be 2.6 from the accumulation capacitance and the thickness of the film, suggesting that the CNx film formed by liquid phase deposition is a promising low-k material for use in ultralarge-scale integration multilevel interconnections.